phenylephrine-hydrochloride and Staphylococcal-Infections

The study aimed at examining the relationship between nasal colonization of Staphylococcus aureus (SA) or methicillin-resistant Staphylococcus aureus (MRSA) and the risk of SSI after spinal surgeries MATERIALS AND METHODS: PubMed, CENTRAL, Scopus, Web of Science, and Embase databases up to 24th September 2022 for articles on nasal colonization of SA/MRSA and spine surgeries.. Ten studies were included. Meta-analysis revealed that the incidence of SSI was not significantly different between SA-positive and SA-negative patients (RR: 0.75, 95% CI: 0.47, 1.18 I2=2% p=0.21). It was noted that when no decolonization was done, there was no statistically significant difference in the risk of SSI between MRSA positive and MRSA negative patients, but a tendency of higher SSI in MRSA carriers (RR: 2.40, 95% CI: 0.91, 6.32, I2=37% p=0.08). However, in the subgroup analysis with decolonization, the risk of SSI was significantly higher in the MRSA-positive group (RR: 2.99, 95% CI: 1.27, 7.03, I2=24% p=0.01). Specifically, the risk of MRSA-SSI was significantly higher in MRSA carriers with (RR: 6.05, 95% CI: 1.14, 31.99, I2=43% p=0.03) and without decolonization (RR: 7.54, 95% CI: 1.43, 39.85, I2=38% p=0.02).. Evidence from observational studies indicates that only MRSA nasal colonization increases the risk of SSIs in spinal surgery patients. Nasal decolonization was unable to reduce the risk of overall or MRSA-specific SSIs in MRSA carriers. Evidence was biased due to the extremely small number of MRSA-positive patients in the studies and the lack of adjustment of confounding factors.

Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Staphylococcus aureus (SA) is a frequent colonizer in humans, and it is known to be associated with chronic allergic diseases including asthma. Recent individual studies suggested that nasal SA colonization may be positively associated with asthma.. To examine relationships between nasal SA colonization and asthma prevalence and activity in adults.. Electronic databases were searched for studies published until June 2018. Studies that reported nasal SA colonization prevalence and asthma outcome (prevalence and disease activity) in general adult populations or patients with chronic rhinosinusitis (CRS) were included. Random effects meta-analyses were performed to calculate pooled odds ratio (OR) of the relationships. Subgroup analysis was conducted for the presence of nasal polyps within CRS populations.. A total of 21 cross-sectional studies were identified, and the data from 16 studies using culture methods for SA detection were meta-analyzed (5 general population-based studies and 11 studies of patients with CRS). In studies of general populations, nasal SA colonization had significant relationships with asthma prevalence (OR 1.19; 95% confidence interval [CI] 1.06-1.34; I. This study demonstrated modest but significant relationships between nasal SA colonization and asthma, supporting potential roles of SA in adult patients with asthma. Further longitudinal cohort and intervention studies are warranted to identify host determinants and to clarify causality of the relationships.

Topics: Adult; Asthma; Chronic Disease; Humans; Nose; Prevalence; Rhinitis; Sinusitis; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Drug Development; Humans; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

Menstrual toxic shock syndrome (mTSS) is a life-threatening disease caused by superantigen-producing Staphylococcus aureus. Incidence ranges from 0·03 to 0·50 cases per 100 000 people, with overall mortality around 8%. In this Grand Round, we present the case of a previously healthy 23-year-old menstruating woman who was diagnosed with mTSS after she presented at our hospital with a septic condition for the second time. The diagnosis was confirmed by fulfilment of the clinical criteria outlined by the US Centers for Disease Control and Prevention (CDC; fever, rash, desquamation, hypotension, and multi-system involvement) as well as a nasal swab positive for the S aureus strain and presence of the gene encoding for toxic shock syndrome toxin 1 (TSST-1). In the early 1980s, when mTSS was first described, use of tampons was considered the main risk factor. Today, the complex interplay between pathogenic factors of S aureus, immunological mechanisms of the host, and changes in the vaginal ecosystem during menstruation has broadened current understanding of the disease, and the CDC criteria have appreciable limitations in everyday clinical practice.

Topics: Bacterial Toxins; Enterotoxins; Female; Humans; Menstruation; Nose; Recurrence; Risk Factors; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus; Superantigens; Young Adult

Viral infections of the respiratory tract can be complicated by bacterial superinfection, resulting in a significantly longer duration of illness and even a fatal outcome. In this review, we focused on interactions between S. aureus and non-influenza viruses. Clinical data evidenced that rhinovirus infection may increase the S. aureus carriage load in humans and its spread. In children, respiratory syncytial virus infection is associated with S. aureus carriage. The mechanisms by which some non-influenza respiratory viruses predispose host cells to S. aureus superinfection can be summarized in three categories: i) modifying expression levels of cellular patterns involved in S. aureus adhesion and/or internalization, ii) inducing S. aureus invasion of epithelial cells due to the disruption of tight junctions, and iii) decreasing S. aureus clearance by altering the immune response. The comprehension of pathways involved in S. aureus-respiratory virus interactions may help developing new strategies of preventive and curative therapy.

Topics: Animals; Bacterial Adhesion; Carrier State; Disease Models, Animal; Epithelial Cells; Host-Pathogen Interactions; Humans; Mice; Microbial Interactions; Nose; Picornaviridae Infections; Respiratory Syncytial Virus Infections; Respiratory System; Respiratory Tract Infections; Rhinovirus; Staphylococcal Infections; Staphylococcus aureus; Superinfection; Virus Diseases

Surgical site infection rates in the month following surgery vary from 1% to 5%. Due to the large number of surgical procedures conducted annually, the costs of these surgical site infections (SSIs) can be considerable in financial and social terms. Nasal decontamination using antibiotics or antiseptics is performed to reduce the risk of SSIs by preventing organisms from the nasal cavity being transferred to the skin where a surgical incision will be made. Staphylococcus aureus (S aureus) colonises the nasal cavity and skin of carriers and can cause infection in open or unhealed surgical wounds. S aureus is the leading nosocomial (hospital-acquired) pathogen in hospitals worldwide. The potential effectiveness of nasal decontamination of S aureus is thought to be dependent on both the antibiotic/antiseptic used and the dose of application; however, it is unclear whether nasal decontamination actually reduces postoperative wound infection in S aureus carriers.. To assess the effects of nasal decontamination on preventing surgical site infections (SSIs) in people who are S aureus carriers undergoing surgery.. In September 2016 we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library), Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched three clinical trial registries and the references of included studies and relevant systematic reviews. There were no restrictions based on language, date of publication or study setting.. Randomised controlled trials (RCTs) which enrolled S aureus carriers with any type of surgery and assessed the use of nasal decontamination with antiseptic/antibiotic properties were included in the review.. Two review authors independently performed study selection, data extraction, risk of bias assessment and GRADE assessment.. We located two studies (291 participants) for inclusion in this review. The trials were clinically heterogeneous with differences in duration of follow-up, and nasal decontamination regimens. One study compared mupirocin (2% contained in a base of polyethylene glycol 400 and polyethylene glycol 3350) with a placebo in elective cardiac surgery patients; and one study compared Anerdian (iodine 0.45% to 0.57% (W/V), chlorhexidine acetate 0.09% to 0.11% (W/V)) with no treatment also in cardiac surgery patients. The trials reported limited outcome data on SSI, adverse events and secondary outcomes (e.g. S aureus SSI, mortality). Mupirocin compared with placeboThis study found no clear difference in SSI risk following use of mupirocin compared with placebo (1 trial, 257 participants); risk ratio (RR) 1.60, 95% confidence interval (CI) 0.79 to 3.25 based on 18/130 events in the mupirocin group and 11/127 in the control group; low-certainty evidence (downgraded twice due to imprecision). Anerdian compared with no treatmentIt is uncertain whether there is a difference in SSI risk following treatment with Anerdian compared with no treatment (1 trial, 34 participants); RR 0.89, 95% CI 0.06 to 13.08 based on 1/18 events in the Anerdian group and 1/16 in the control group; very low certainty evidence (downgraded twice due to imprecision and once due to risk of bias).. There is currently limited rigorous RCT evidence available regarding the clinical effectiveness of nasal decontamination in the prevention of SSI. This limitation is specific to the focused question our review addresses, looking at nasal decontamination as a single intervention in participants undergoing surgery who are known S aureus carriers. We were only able to identify two studies that met the inclusion criteria for this review and one of these was very small and poorly reported. The potential benefits and harms of using decontamination for the prevention of SSI in this group of people remain uncertain.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Cardiac Surgical Procedures; Carrier State; Chlorhexidine; Drug Combinations; Humans; Iodine; Mupirocin; Nose; Randomized Controlled Trials as Topic; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Although human colonization by facultative bacterial pathogens, such as Staphylococcus aureus, represents a major risk factor for invasive infections, the commensal lifestyle of such pathogens has remained a neglected area of research. S. aureus colonizes the nares of approximately 30% of the human population and recent studies suggest that the composition of highly variable nasal microbiota has a major role in promoting or inhibiting S. aureus colonization. Competition for epithelial attachment sites or limited nutrients, different susceptibilities to host defence molecules and the production of antimicrobial molecules may determine whether nasal bacteria outcompete each other. In this Review, we discuss recent insights into mechanisms that are used by S. aureus to prevail in the human nose and the counter-strategies that are used by other nasal bacteria to interfere with its colonization. Understanding such mechanisms will be crucial for the development of new strategies for the eradication of endogenous facultative pathogens.

Topics: Animals; Disease Models, Animal; Drug Resistance, Multiple, Bacterial; Host-Pathogen Interactions; Humans; Microbiota; Models, Molecular; Nasal Cavity; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

MRSA infections in equine clinics were reported from Northern America, Europe, Australia, and Japan. The majority of nosocomial infections in horses is obviously associated with particular MRSA clonal lineages. As already observed for epidemic MRSA in human hospitals more than 10 years ago, a dynamics of MRSA clonal lineages is also observed in European equine clinics: clonal lineages belonging to clonal complex (CC) 8 are on the retreat whereas MRSA attributed to CC398 become increasingly prevalent. The majority of CC398 isolates belong to a subpopulation which is particularly associated with equine hospitals as indicated by molecular typing. When emerging in equine clinics, MRSA from horses were also found as nasal colonizers of veterinary personnel. MRSA exhibiting the typing characteristics of MRSA known from equine clinics are obviously rare among MRSA from infections in humans. Although rare so far epidemic MRSA from human hospitals (HA-MRSA, e.g., ST22, ST225) have been isolated from nosocomial infections in horses and need particular attention in further surveillance.

Topics: Animals; Australia; Europe; Genotype; Horse Diseases; Horses; Hospitals, Animal; Humans; Japan; Methicillin-Resistant Staphylococcus aureus; North America; Nose; Prevalence; Staphylococcal Infections

A systematic literature review and meta-analysis was performed to identify effectiveness of mupirocin decolonization in prevention of Staphylococcus aureus infections, among nonsurgical settings. Of the 15 662 unique studies identified up to August 2015, 13 randomized controlled trials, 22 quasi-experimental studies, and 1 retrospective cohort study met the inclusion criteria. Studies were excluded if mupirocin was not used for decolonization, there was no control group, or the study was conducted in an outbreak setting. The crude risk ratios were pooled (cpRR) using a random-effects model. We observed substantial heterogeneity among included studies (I(2) = 80%). Mupirocin was observed to reduce the risk for S. aureus infections by 59% (cpRR, 0.41; 95% confidence interval [CI], .36-.48) and 40% (cpRR, 0.60; 95% CI, .46-.79) in both dialysis and nondialysis settings, respectively. Mupirocin decolonization was protective against S. aureus infections among both dialysis and adult intensive care patients. Future studies are needed in other settings such as long-term care and pediatrics.

Topics: Anti-Bacterial Agents; Humans; Intensive Care Units; Mupirocin; Nose; Renal Dialysis; Staphylococcal Infections

Perioperative decolonization of Staphylococcus aureus nasal carriers with mupirocin together with chlorhexidine body washing reduces the incidence of S. aureus surgical site infection. A targeted strategy, applied in S. aureus carriers only, is costly, and implementation may reduce effectiveness. Universal decolonization is more cost-effective but increases exposure of noncarriers to mupirocin and the risk of resistance to mupirocin in staphylococci. High-level mupirocin resistance in S. aureus can emerge through horizontal gene transfer originating from coagulase-negative staphylococci (CoNS) and through clonal transmission. The current evidence on the occurrence of high-level mupirocin resistance in S. aureus and CoNS, in combination with the results of mathematical modeling, strongly suggests that the increased selection of high-level mupirocin resistance in CoNS does not constitute an important risk for high-level mupirocin resistance in S. aureus. Compared with a targeted strategy, universal decolonization seems associated with an equally low risk of mupirocin resistance in S. aureus.

Topics: Administration, Intranasal; Baths; Chlorhexidine; Decontamination; Drug Resistance, Bacterial; Humans; Models, Biological; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Staphylococcus aureus (S. aureus) is a Gram-positive opportunistic pathogen that colonizes frequently and asymptomatically the anterior nares of humans and animals. It can cause different kinds of infections and is considered to be an important nosocomial pathogen. Nasal carriage of S. aureus can be permanent or intermittent and may build the reservoir for autogenous infections and cross-transmission to other individuals. Most of the studies on the epidemiology of S. aureus performed in the past were focused on the emergence and dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare settings. There are, however, a number of more recent epidemiological studies have aimed at analysing carriage patterns over time in the community settings providing new insights on risk factors for colonization and important data for the development of strategies to prevent infections. This chapter aims to give a review of current epidemiological studies on S. aureus carriage patterns in the general community and put them into perspective with recent, yet unpublished, investigations on the S. aureus epidemiology in the general population in northern Germany.

Topics: Carrier State; Drug Resistance, Bacterial; Humans; Nose; Residence Characteristics; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus persistently colonizes the anterior nares of approximately one fifth of the population and nasal carriage is a significant risk factor for infection. Recent advances have significantly refined our understanding of S. aureus-host communication during nasal colonization. Novel bacterial adherence mechanisms in the nasal epithelium have been identified, and novel roles for both the innate and the adaptive immune response in controlling S. aureus nasal colonization have been defined, through the use of both human and rodent models. It is clear that S. aureus maintains a unique, complex relationship with the host immune system and that S. aureus nasal colonization is overall a multifactorial process which is as yet incompletely understood.

Topics: Adaptive Immunity; Animals; Bacterial Adhesion; Carrier State; Disease Models, Animal; Epithelial Cells; Host-Pathogen Interactions; Humans; Immunity, Innate; Microbial Interactions; Microbiota; Nasal Cavity; Nasal Mucosa; Nose; Risk Factors; Rodentia; Staphylococcal Infections; Staphylococcus aureus

To estimate the prevalence and significance of nasal methicillin-resistant Staphylococcus aureus colonization in the ICU and its predictive value for development of methicillin-resistant S. aureus infection.. MEDLINE and EMBASE and reference lists of all eligible articles.. Studies providing raw data on nasal methicillin-resistant S. aureus colonization at ICU admission, published up to February 2013. Analyses were restricted in the general ICU setting. Medical, surgical, and interdisciplinary ICUs were eligible. ICU studies referring solely on highly specialized ICUs populations and reports on methicillin-resistant S. aureus outbreaks were excluded.. Two authors independently assessed study eligibility and extrapolated data in a blinded fashion. The two outcomes of interest were the prevalence estimate of methicillin-resistant S. aureus nasal colonization at admission in the ICU and the sensitivity/specificity of colonization in predicting methicillin-resistant S. aureus-associated infections.. Meta-analysis, using a random-effect model, and meta-regression were performed. Pooled data extracted from 63,740 evaluable ICU patients provided an estimated prevalence of methicillin-resistant S. aureus nasal colonization at admission of 7.0% (95% CI, 5.8-8.3). Prevalence was higher for North American studies (8.9%; 95% CI, 7.1-10.7) and for patients screened using polymerase chain reaction (14.0%; 95% CI, 9.6-19). A significant per year increase in methicillin-resistant S. aureus colonization was also noted. In 17,738 evaluable patients, methicillin-resistant S. aureus infections (4.1%; 95% CI, 2.0-6.8) developed in 589 patients. The relative risk for colonized patients was 8.33 (95% CI, 3.61-19.20). Methicillin-resistant S. aureus nasal carriage had a high specificity (0.96; 95% CI, 0.90-0.98) but low sensitivity (0.32; 95% CI, 0.20-0.48) to predict methicillin-resistant S. aureus-associated infections, with corresponding positive and negative predictive values at 0.25 (95% CI, 0.11-0.39) and 0.97 (95% CI, 0.83-1.00), respectively.. Among ICU patients, 5.8-8.3% of patients are colonized by methicillin-resistant S. aureus at admission, with a significant upward trend. Methicillin-resistant S. aureus colonization is associated with a more than eight-fold increase in the risk of associated infections during ICU stay, and methicillin-resistant S. aureus infection develops in one fourth of patients who are colonized with methicillin-resistant S. aureus at admission to the ICU.

Topics: Humans; Intensive Care Units; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Admission; Prevalence; Staphylococcal Infections

Staphylococcus aureus nasal carriage is a well-defined risk factor of infection with this bacterium. The increased risk of S. aureus infection in nasal carriers is supported by the fact that the strains isolated from both colonization and infection sites are indistinguishable in most of the cases. Persistent nasal carriage seems to be associated with an increased risk of infection and this status could be defined now in clinical routine by using one or two quantitative nasal samples. There is evidence for supporting the detection of nasal carriage of S. aureus in patients undergoing cardiac surgery and in those undergoing hemodialysis in order to implement decolonization measures. More studies are needed to determine which carriers have the highest risk of infection and why decolonization strategies failed to reduce S. aureus infection in some other groups of patients.

Topics: Humans; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

To evaluate studies assessing the effectiveness of a bundle of nasal decolonization and glycopeptide prophylaxis for preventing surgical site infections caused by Gram positive bacteria among patients undergoing cardiac operations or total joint replacement procedures.. Systematic review and meta-analysis.. PubMed (1995 to 2011), the Cochrane database of systematic reviews, CINAHL, Embase, and clinicaltrials.gov were searched to identify relevant studies. Pertinent journals and conference abstracts were hand searched. Study authors were contacted if more data were needed.. Randomized controlled trials, quasi-experimental studies, and cohort studies that assessed nasal decolonization or glycopeptide prophylaxis, or both, for preventing Gram positive surgical site infections compared with standard care.. Patients undergoing cardiac operations or total joint replacement procedures. DATA EXTRACTION AND STUDY APPRAISAL: Two authors independently extracted data from each paper and a random effects model was used to obtain summary estimates. Risk of bias was assessed using the Downs and Black or the Cochrane scales. Heterogeneity was assessed using the Cochran Q and I(2) statistics.. 39 studies were included. Pooled effects of 17 studies showed that nasal decolonization had a significantly protective effect against surgical site infections associated with Staphylococcus aureus (pooled relative risk 0.39, 95% confidence interval 0.31 to 0.50) when all patients underwent decolonization (0.40, 0.29 to 0.55) and when only S aureus carriers underwent decolonization (0.36, 0.22 to 0.57). Pooled effects of 15 prophylaxis studies showed that glycopeptide prophylaxis was significantly protective against surgical site infections related to methicillin (meticillin) resistant S aureus (MRSA) compared with prophylaxis using β lactam antibiotics (0.40, 0.20 to 0.80), and a non-significant risk factor for methicillin susceptible S aureus infections (1.47, 0.91 to 2.38). Seven studies assessed a bundle including decolonization and glycopeptide prophylaxis for only patients colonized with MRSA and found a significantly protective effect against surgical site infections with Gram positive bacteria (0.41, 0.30 to 0.56).. Surgical programs that implement a bundled intervention including both nasal decolonization and glycopeptide prophylaxis for MRSA carriers may decrease rates of surgical site infections caused by S aureus or other Gram positive bacteria.

Topics: Antibiotic Prophylaxis; Arthroplasty, Replacement; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Surgical Wound Infection

Staphylococcus aureus may cause serious skin and soft tissue infections, deep abscesses, endocarditis, osteomyelitis, pneumonia, and sepsis. S. aureus persistently colonizes 25-30% of the adult human population, and S. aureus carriers have an increased risk for infections caused by the bacterium. The major site of colonization is the nose, i.e., the vestibulum nasi, which is covered with ordinary skin and hair follicles. Several host and microbe determinants are assumed to be associated with colonization. These include the presence and expression level of bacterial adhesins, which can adhere to various proteins in the extracellular matrix or on the cellular surface of human skin. The host expresses several antimicrobial peptides and lipids. The level of β-defensin 3, free sphingosine, and cis-6-hexadecenoic acid are found to be associated with nasal carriage of S. aureus. Other host factors are certain polymorphisms in Toll-like receptor 2, mannose-binding lectin, C-reactive protein, glucocorticoid-, and vitamin D receptor. Additional putative determinants for carriage include genetic variation and expression of microbial surface components recognizing adhesive matrix molecules and their interaction partners, as well as variation among humans in the ability of recognizing and responding appropriately to the bacteria. Moreover, the available microflora may influence the success of S. aureus colonization. In conclusion, colonization is a complex interplay between the bacteria and its host. Several bacterial and host factors are involved, and an increased molecular understanding of these are needed.

Topics: Antimicrobial Cationic Peptides; Carrier State; Host-Pathogen Interactions; Humans; Nose; Receptors, Immunologic; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

This review focuses on comorbidities between nose and skin allergies. For this purpose, allergic rhinitis and chronic rhinosinusitis (CRS) were selected as examples of nasal disorders and atopic dermatitis and urticaria as examples of allergic skin disorders and the individual entities of both localizations were evaluated and compared in relation to their prevalence and coincidence, underlying pathophysiological mechanisms, genetic data and shared therapy options.. The inter-relationships between atopic dermatitis and allergic rhinitis are the best studied, but even for the other comorbidities it was possible to demonstrate comparable pathomechanisms in addition to a high prevalence and coincidence, particularly in the case of atopically assisted forms. In this context, the interactions of IgE, mast cells and eosinophils play a special role, but genetic issues, the significance of epithelial barrier defects and colonization with Staphylococcus aureus are also important sharing issues.. Allergic skin disorders such as atopic dermatitis and urticaria are frequently associated with comorbidities of the nose as well as allergic rhinitis and CRS. By contrast, different manifestations of these diseases involve the nose and the skin. These are not separate diseases but are linked by complex and currently unclear/insufficiently defined inter-relationships.

Topics: Comorbidity; Dermatitis, Atopic; Eosinophils; Humans; Immunoglobulin E; Mast Cells; Nose; Respiratory Hypersensitivity; Rhinitis; Sinusitis; Skin; Staphylococcal Infections; Staphylococcus aureus; Urticaria

Topics: Adolescent; Adult; Anti-Bacterial Agents; Anti-Infective Agents, Local; Disease Transmission, Infectious; Germany; Gloves, Protective; Hand Disinfection; Hospitalization; Humans; Incidence; Infant, Newborn; Infection Control; Intensive Care Units; Intensive Care Units, Neonatal; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Patient Isolation; Randomized Controlled Trials as Topic; Risk Factors; Sepsis; Staphylococcal Infections

Staphylococcus aureus is a medically important pathogen that is often acquired from hospital settings (nosocomial) as well as from the community (community acquired). Bacteria that reside in anterior nares of hosts serve as reservoirs for both the spread of the pathogen and predispose the host to subsequent infections. Here, we will review the extent and variability of nasal carriage, and the possible causative factors--both from the host and the bacterium. We also discuss the existing molecular typing techniques used for studying variations among strains of S. aureus. Finally, we discuss the possible areas of studies that are open in this field. Given the pathogen's importance in healthcare setting, such areas of study vary vastly, from fundamental research to applied medical care and use of alternative medical regimes for control of S. aureus nasal carriage. Unsurprisingly, our conclusions also underscore the importance of making policy decisions based on local ethnic and socioeconomic population structure.

Topics: Bacterial Proteins; Carrier State; Host-Pathogen Interactions; Humans; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The natural habitat of Staphylococcus aureus in humans is the moist squamous epithelium of the anterior nares. Several bacterial surface proteins are implicated in promoting adhesion to desquamated epithelial cells. Clumping factor B (ClfB) and iron-regulated surface determinant A both promote nasal colonization in rodent models, and in the case of ClfB, humans. One of the ligands involved in adhesion is cytokeratin 10. Reduction in nasal colonization can be achieved by active and passive immunization. S. aureus is well endowed with secreted and surface components that compromise innate immune responses, particularly the function of neutrophils. S. aureus secretes proteins that reduce migration of neutrophils from the bloodstream to the site of infection by impeding diapedesis and receptors for chemotactic molecules. Several secreted proteins interfere with complement C3 and C5 convertases, thus reducing the level of C3b opsonin and the chemotactic peptide C5a. Host proteases are recruited to the cell surface to enhance destruction of opsonic C3b and IgG. Surface components ClfA, protein A and polysaccharide capsule compromise the recognition of opsonins on the bacterial cell surface. If engulfed by neutrophils the intracellular bacterium can resist reactive oxygen intermediates, nitric oxide radicals, defensin peptides and bactericidal proteins. A prior infection by S. aureus does not induce complete protective immunity. This could be due to immunosuppression caused by expression of superantigen proteins that disrupt normal activation of T cells and B cells during antigen presentation. By studying the molecular pathogenesis of S. aureus infections markers might be found for investigating S. pseudintermedius infections of dogs.

Topics: Bacterial Adhesion; Carrier State; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

This short review attempts to examine whether there is a potential for the use of phages capable of infecting Staphylococcus aureus to eradicate or reduce nasal colonisation, thereby reducing the overall infection burden in patient populations identified as being at risk from MRSA infections. There is clear evidence that nasal decolonisation may be of benefit to certain patient groups and also that phages can effectively combat experimentally induced S. aureus infections in animals. However, this is not in itself enough to validate the use of phages for decolonisation and, given the appearance of strains resistant to currently used topical antibiotics, there is a need for clinical trials of this prophylactic use of phages.

Topics: Animals; Bacteriophages; Humans; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus (S. aureus) is the leading nosocomial (hospital acquired) pathogen in hospitals throughout the world. Traditionally, control of S. aureus has been focused on preventing cross-infection between patients, however, it has been shown repeatedly that a large proportion of nosocomial S. aureus infections originate from the patient's own flora. Nasal carriage of S. aureus is now considered a well defined risk factor for subsequent infection in various groups of patients. Local antibiotic treatment with mupirocin ointment is often used to eradicate nasal S. aureus.. To determine whether the use of mupirocin nasal ointment in patients with identified S. aureus nasal carriage reduced S. aureus infection rates.. We searched the Cochrane Wounds Group Specialised Register (May 2008), the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2 2008), MEDLINE (1950 to May 2008), EMBASE (1980 to May 2008) and CINAHL (1982 to May 2008). To identify unpublished trials, abstract books from major scientific meetings (ICAAC, ESCMID and SHEA) were handsearched, researchers and manufacturers of mupirocin were contacted and other electronic databases were searched (SIGLE, ASLIB Index, mRCT, USA Clinical Trials).. Randomised controlled trials (RCTs) comparing nasal mupirocin with no treatment or placebo or alternative nasal treatment in the prevention of S. aureus infections in nasal S. aureus carriers were included.. Titles, abstracts and full-text articles of studies retrieved from the search process were independently assessed by two authors for inclusion. From included studies a data extraction form was made and the quality of the trial was assessed. The primary outcome was the S. aureus infection rate (any site). Secondary outcomes were time to infection, mortality, adverse events and infection rate caused by micro-organisms other than S. aureus.. Nine RCTs involving 3396 participants met the inclusion criteria. Patient populations varied and several types of nosocomial S. aureus infection were described including bacteraemia, exit-site infections, peritonitis, respiratory tract infections, skin infections, surgical site infections (SSI) and urinary tract infections. After pooling the eight studies that compared mupirocin with placebo or with no treatment, there was a statistically significant reduction in the rate of S. aureus infection associated with intranasal mupirocin (RR 0.55, 95% CI 0.43 to 0.70).A planned subgroup analysis of surgical trials demonstrated a significant reduction in the rate of nosocomial S. aureus infection rate associated with mupirocin use (RR 0.55, 95% CI 0.34 to 0.89) however this effect disappeared if the analysis only included surgical site infections caused by S. aureus (RR 0.63, 95% CI 0.38 to 1.04), possibly due to a lack of power. The infection rate caused by micro-organisms other than S. aureus was significantly higher in patients treated with mupirocin compared with control patients (RR 1.38 95% CI 1.118 to 1.72).. In people who are nasal carriers of S. aureus, the use of mupirocin ointment results in a statistically significant reduction in S. aureus infections.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Carrier State; Humans; Mupirocin; Nose; Ointments; Randomized Controlled Trials as Topic; Staphylococcal Infections; Staphylococcus aureus

Methicillin resistant Staphylococcus aureus (MRSA) is becoming ever more prevalent in the UK, and the proportion of MRSA to methicillin sensitive Staphylococcus aureus (MSSA) seems to be increasing. New strains of MRSA are ever developing resistance to antibiotic treatment, increasing morbidity and mortality of infection. Staphylococcus aureus is part of the normal flora of the nose, and MRSA colonizes the nose in infection. However, nasal surgery is rarely complicated by staphylococcal infections, and MRSA infection following nasal surgery is rare. The authors present a literature review of MRSA infection, its relation to the nasal cavity, and infection following nasal surgery.

Topics: Carrier State; Humans; Methicillin Resistance; Nose; Nose Diseases; Postoperative Complications; Prevalence; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Carrier State; Hospitals; Humans; Methicillin Resistance; Mupirocin; Nose; Randomized Controlled Trials as Topic; Staphylococcal Infections; Staphylococcus aureus

This review summarizes the clinically relevant aspects of nasal carriage of Staphylococcus aureus. The epidemiology, associated risk, and the effects of eradication are discussed. The main conclusions are that nasal carriage of S. aureus is a well-defined risk factor for subsequent infection in nearly all categories of hospitalized patients that have been studied. However, studies that have been performed to evaluate the effect of eradication of carriage using mupirocin nasal ointment have been inconclusive so far in most subgroups. Only in patients on hemodialysis or chronic ambulatory peritoneal dialysis (CAPD) was a significant reduction of the infection rate found. But prolonged treatment in these groups carries a risk for the development of resistance. In surgical patients two randomized studies have found an effect on the surgical site infection rate in carriers that, when those studies are combined, was close to being statistically significant (p = 0.06). In non-surgical patients a significant delay in the onset of infection was found but the overall infection rate was not significantly different. When the results of all well-designed studies that have been performed are combined, a significant reduction of the nosocomial S. aureus infections in carriers is found (approximately 50% lower). Future studies should focus on treating carriers only and consider other treatment regimens.

Topics: Anti-Bacterial Agents; Carrier State; Cost-Benefit Analysis; Cross Infection; Humans; Nasal Mucosa; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcal Vaccines; Staphylococcus aureus

Staphylococcus aureus is a frequent cause of infections in both the community and hospital. Worldwide, the increasing resistance of this pathogen to various antibiotics complicates treatment of S aureus infections. Effective measures to prevent S aureus infections are therefore urgently needed. It has been shown that nasal carriers of S aureus have an increased risk of acquiring an infection with this pathogen. The nose is the main ecological niche where S aureus resides in human beings, but the determinants of the carrier state are incompletely understood. Eradication of S aureus from nasal carriers prevents infection in specific patient categories-eg, haemodialysis and general surgery patients. However, recent randomised clinical trials in orthopaedic and non-surgical patients failed to show the efficacy of eliminating S aureus from the nose to prevent subsequent infection. Thus we must elucidate the mechanisms behind S aureus nasal carriage and infection to be able to develop new preventive strategies. We present an overview of the current knowledge of the determinants (both human and bacterial) and risks of S aureus nasal carriage. Studies on the population dynamics of S aureus are also summarised.

Topics: Adolescent; Adult; Aged; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Middle Aged; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The current literature indicates that surgical-site infections significantly increase costs and length of stay. Nosocomial infections that are acquired after operative procedures increase mortality rates. Staphylococcus aureus is a major cause of surgical-site infections among patients, particularly patients who undergo cardiothoracic surgery. Patients who carry S aureus in their nares are at increased risk for surgical-site infections that are caused by this organism. Occasionally, health care workers who carry S aureus in their nares can cause outbreaks of surgical-site infections or other nosocomial infections. Persons who carry S aureus in their nares and have upper respiratory tract infections may spread this organism to numerous staff members and patients. Key measures for decreasing rates of these and other nosocomial infections include the appropriate use of prophylactic antimicrobial agents, surveillance and reporting of infections, and surveillance for clusters of infection caused by the same strain of S aureus and culture and surveys, when appropriate, to help identify infected health care workers. Additionally, surgical masks may prevent health care workers from inadvertent transmission of S aureus from their nares to patients' surgical sites.

Topics: Cardiac Surgical Procedures; Carrier State; Cross Infection; Humans; Infectious Disease Transmission, Professional-to-Patient; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Health care-related infections cause significant patient morbidity and mortality rates and add excess costs that frequently are not reimbursed. Staphylococcus aureus has long been recognized as an important pathogen in human disease and is the most common cause of nosocomial infections.. The objective of this review of the English language literature and a MEDLINE search was to describe recent advances in the prevention of S aureus health care-related infections that are attributable to patients' endogenous colonization. The ecologic niche of S aureus is the anterior nares and nasal carriage increases the risk of the development of a surgical-site, lower respiratory tract, or bloodstream infection. S aureus carriers have a 2- to 9-fold increased risk of the development of a surgical-site or intravenous catheter infection.. Three treatment strategies may eliminate nasal carriage: locally applied antibiotics or disinfectants, systemic antibiotics, and bacterial interference. Among these strategies, locally applied or systemic antibiotics are used most commonly. Nasal ointments or sprays and oral antibiotics have variable efficacy, and their use frequently results in antimicrobial resistance among S aureus strains. Of the commonly used agents, mupirocin (pseudomonic acid) ointment has been shown to be 97% effective in reducing S aureus nasal carriage. In a recently published randomized, double-blind, placebo-controlled trial to determine whether intranasal mupirocin reduced the rate of S aureus-infected surgical-site and other S aureus health care-related infections; 4% of S aureus nasal carriers who received mupirocin acquired S aureus health care-related infections compared with 7.7% of S aureus nasal carriers who received placebo (P=.02). The S aureus surgical-site infection rate was not reduced significantly, but carriers who received mupirocin before cardiothoracic or general surgery operations had almost 50% fewer S aureus surgical-site infections than carriers who received placebo. In this setting resistance rarely has been reported.. Given the importance of S aureus nosocomial infections and the increased risk of S aureus nasal carriage in patients with health care-related infections, investigators must study cost-effective strategies to further prevent certain types of health care-related infections or nosocomial infections that occur in specific settings. One potential strategy is to decrease or eliminate S aureus nasal carriage among certain patient populations or in certain healthcare settings.

Topics: Carrier State; Cost-Benefit Analysis; Cross Infection; Drug Resistance, Bacterial; Humans; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Humans; Infection Control; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Vancomycin Resistance; Wounds and Injuries

Nasal carriage of Staphylococcus aureus is an important risk factor for infection by this organism in both community and hospital settings; this article reviews the role of host and bacterial factors in carriage. A host genetic influence appears likely but the phenotypic determinants are unknown. Possibilities include variability in host adhesins, immune response or secretion of antimicrobial molecules. Colonization resistance by S. aureus, together with the observation that persistent carriers often carry a single strain whereas intermittent carriers can be colonized with unrelated strains over time, suggests that bacterial factors could also be involved.

Topics: Carrier State; Genetic Predisposition to Disease; Humans; Immune System; Nasal Mucosa; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen in many hospitals worldwide. Even more alarming, MRSA strains that are vancomycin intermediate-susceptible are isolated with increasing frequency, making therapy for staphylococcal infections even more difficult and prevention more important than ever. Spread of S. aureus in hospitals and infection control measures are reviewed. The major sources of S. aureus in hospitals are septic lesions and carriage sites of patients and personnel. Carriage often precedes infection. The anterior nares are the most consistent carriage site, followed by the perineal area. Skin contamination and aerial dissemination vary markedly between carriers and are most pronounced for combined nasal and perineal carriers. The principal mode of transmission is via transiently contaminated hands of hospital personnel. Airborne transmission seems important in the acquisition of nasal carriage. Infection control strategies include screening and isolation of newly admitted patients suspected of carrying MRSA or S. aureus with intermediáte resistance to vancomycin, implementation of an infection control program to prevent transmission of resistant strains between patients and hospital personnel, and institution of a proper antibiotic policy to minimize antibiotic resistance development. MRSA carriers should be treated with intranasal antibiotics, e.g. mupirocin, and skin disinfectants to eliminate carriage. Education of hospital personnel is essential. Improved knowledge about the best ways to ensure favourable infection control practices is needed. Active intervention against the spread of MRSA is important.

Topics: Carrier State; Cost-Benefit Analysis; Cross Infection; Drug Resistance, Multiple, Bacterial; Humans; Infection Control; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus; Vancomycin Resistance

Topics: Animals; Carrier State; Communicable Diseases; Cross Infection; Humans; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

To provide medical personnel with a definition of an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) and guidelines for managing potential outbreaks.. Eighteen panel members were chosen from different specialties, types of institutions, and geographic regions. Representatives from the American Society of Consultant Pharmacists, the American Society of Health-Systems Pharmacists, the Society for Healthcare Epidemiology of America, and the National Association of Directors of Nursing Administration participated.. In preparation for the conference, panel members reviewed the literature and wrote abstracts outlining their personal opinions on the core issues, which were circulated to all participants. During a weekend conference, the panel summarized the reviewed literature, defined an MRSA outbreak, and developed management guidelines.. Published literature, clinical experience, and expert opinion concerning the emergence and subsequent management of MRSA cases in health care institutions.. An outbreak of MRSA was defined as either an increase in the rate of MRSA cases or a clustering of new cases due to the transmission of a single microbial strain in the health care institution. An increased rate of cases can be defined statistically or experientially and includes both infected and colonized patients. A potential outbreak should trigger stepwise, multidisciplinary actions consisting of basic epidemiologic procedures (phase I) to form an initial epidemiologic hypothesis of an outbreak (phase II) followed by a standard epidemiologic workup (phase III) and microbiologic studies (phase IV) to confirm the hypothesis. Mupirocin calcium treatments should be considered to decolonize health care workers during the fourth phase, even before typing is completed.. Until studies can be conducted to delineate the effectiveness of different recommendations, the proposed guidelines may provide a useful starting point that can be adapted to meet an individual institution's specific needs.

Topics: Disease Outbreaks; Guidelines as Topic; Hospital Units; Humans; Infection Control; Methicillin Resistance; Microbiological Techniques; Nose; Population Surveillance; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus; United States

For the last fifty years, the nose has been intermittently recognized and targeted as a source of Staphylococcus aureus causing surgical site infection. In London in 1959, Williams and co-workers established for the first time that nasal carriers had increased rates of surgical sepsis compared with non-carriers. For half of these patients, the source was the patient's own nose. Post-admission acquisition of tetracycline-resistant strains was associated with even higher rates of infection. The increasing appearance of epidemic methicillin-resistant S. aureus (MRSA) in the 1980s rekindled interest in these (largely overlooked) studies, when the elimination of nasal carriage by topical mupirocin proved pivotal for the control of MRSA in Northern Europe and elsewhere. In the late 1980s and 1990s, Boelaert, Holton and others, appreciating the work performed forty years previously, used nasal mupirocin for the successful prevention of sepsis with S. aureus in patients on haemodialysis and continuous ambulatory peritoneal dialysis without incurring problems with mupirocin resistance. In 1995, Kluytmans and colleagues demonstrated that nasal carriage of S. aureus is a significant risk factor for wound infection after cardiac surgery. Towards the year 2000, the use of prophylactic nasal mupirocin for the prevention of serious sepsis in major clean surgery is emerging as a plausible and exciting new strategy.

Topics: Anti-Bacterial Agents; Carrier State; Humans; Methicillin Resistance; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Numerous studies conducted in different countries and in different populations of patients on dialysis have consistently documented that a large proportion of such patients carry Staphylococcus aureus in their nares and that the risk of them becoming infected with their own strains is quite high. Furthermore, S. aureus infections can cause considerable morbidity and mortality in these patients. Thus, decolonization of the nares may prevent S. aureus infections and the attendant complications. The published data that support the use of rifampicin, intranasal mupirocin and povidone-iodine to prevent S. aureus infections in patients on dialysis are reviewed in detail.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Cost-Benefit Analysis; Humans; Mupirocin; Nose; Peritoneal Dialysis, Continuous Ambulatory; Povidone-Iodine; Renal Dialysis; Rifampin; Staphylococcal Infections; Staphylococcus aureus

In cardiothoracic surgery, the costs of surgical-site infection (SSI) arise from additional postoperative procedures (approximately US $5000 per patient) and prolonged hospital stay (approximately $11,500 per patient). Application of nasal mupirocin reduced SSIs by 63% compared with historical controls. This would have resulted in savings provided that the attributable cost of an SSI was more than $245. Mupirocin was estimated to reduce the risk of bacteraemia in haemodialysis patients by 84% compared with historical controls. A model using data on Medicare payments for haemodialysis admissions was used to estimate the impact on hospital costs. The conclusion was that mupirocin would have been cost-saving but the model did not provide sufficient detail about hospital costing to allow assessment of its relevance in other settings. In a prospective, randomized, placebo-controlled trial in continuous ambulatory peritoneal dialysis (CAPD) patients, mupirocin reduced the risk of staphylococcal exit-site infection (ESI) from 0.42 to 0.14 per patient-year. However, as in a previous comparison with historical controls, there was an increase in the rates of ESIs caused by Gram-negative bacteria in patients who received mupirocin, bringing the rate of total ESIs up to that observed in the placebo group. There was some evidence that infections caused by Gram-negative bacteria had less severe consequences than staphylococcal infections. It is concluded that application of nasal mupirocin to nasal carriers of Staphylococcus aureus may be cost-saving in patients undergoing cardiac surgery or haemodialysis but, if the analysis is restricted to the cost of management of ESIs, it may not be cost-saving in CAPD. However, reducing the risk of staphylococcal ESI may reduce the risk of catheter loss and subsequent transfer to haemodialysis and this merits further study.

Topics: Anti-Bacterial Agents; Carrier State; Cost-Benefit Analysis; Humans; Mupirocin; Nose; Peritoneal Dialysis; Peritoneal Dialysis, Continuous Ambulatory; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Thoracic Surgical Procedures

Staphylococcus aureus has long been recognized as an important pathogen in human disease. Staphylococcal infections occur regularly in hospital patients and, despite antibiotic therapy, have severe consequences. An increasing number of such infections are caused by methicillin-resistant S. aureus (MRSA) strains, many of which have become multi-resistant to treatment. In an unblinded intervention trial, with historical controls, perioperative nasal carriage of S. aureus was eliminated using mupirocin nasal ointment. A significant reduction in surgical site infection was observed post-intervention in the treated group of patients. No resistant to mupirocin was observed. The results of this study warrant a prospective randomized, placebo-controlled study to confirm the efficacy of mupirocin.

Topics: Carrier State; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Nasal mupirocin has an important role to play in the prevention of Staphylococcus aureus infection by eliminating nasal carriage of this organism. Indeed, in many countries nasal mupirocin is one of the mainstays for controlling outbreaks of methicillin-resistant S. aureus. Eradication of nasal S. aureus with mupirocin has been shown to be effective in preventing postoperative infections in patients undergoing cardiothoracic surgery and in preventing exit-site infections in patients undergoing haemodialysis. It has been proposed that the use of mupirocin should be extended to other situations, such as the prevention of postoperative infections in patients undergoing implant surgery and the prevention of bacteraemias in high-risk patients. Clinical trials are needed to establish the efficacy of mupirocin in these situations. Both low-level and high-level resistance have been reported during treatment with nasal mupirocin. Low-level resistance does not represent a significant clinical problem but high-level resistance resulting from indiscriminate use may give grounds for concern. Further review of these issues is required. As with any antibiotic, mupirocin should be used judiciously, as part of an integrated programme of infection control.

Topics: Anti-Bacterial Agents; Bacteremia; Drug Resistance, Microbial; Humans; Methicillin Resistance; Mupirocin; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Staphylococcus aureus infections are associated with considerable morbidity and, in certain situations, mortality. The association between the nasal carriage of S. aureus and subsequent infection has been comprehensively established in a variety of clinical settings, in particular, patients undergoing haemodialysis and continuous ambulatory peritoneal dialysis (CAPD), and in patients undergoing surgery. Postoperative wound infections are associated with a high degree of morbidity and represent an important medical issue. Until recently, eradication of S. aureus nasal carriage by various topical and systemic agents had proved unsuccessful. Mupirocin is a novel topical antibiotic with excellent antibacterial activity against staphylococci. Recent studies have demonstrated that intranasal administration of mupirocin is effective in eradicating the nasal carriage of S. aureus and in reducing the incidence of S. aureus infections in haemodialysis and CAPD patients. It has been suggested that sufficient evidence now exists to test the hypothesis that eradication of the carrier state in surgical patients preoperatively may reduce the incidence of S. aureus postoperative wound infections.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Carrier State; Humans; Incidence; Infection Control; Mupirocin; Nose; Peritoneal Dialysis, Continuous Ambulatory; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

In the United States the rate of postoperative wound infection varies from one to nine per cent, depending on the surgical procedure. Each postoperative wound infection increases the length of stay in hospital, the cost of the procedure and is associated with significant morbidity. Staphylococcus aureus is the causative agent in 15 to 20% of these infections, although the pathogen isolated varies according to the surgical site. Risk factors for acquiring an infection can be divided into the following categories: host factors, surgical and environmental factors, and microbial characteristics. Host factors which may contribute to an increased risk of infection include: age, prolonged pre-operative length of stay, and concurrent infection at another body site. Increased infection risk may result from an extended surgical procedure, the wound classification, the use of a razor for hair removal before surgery and may also be dependent on the surgeon's technical skill. Microbial factors related to the risk of developing an infection postoperatively are less well defined, however, many outbreaks of surgical wound infections have been linked to personnel carrying an organism which is then transmitted to the patient. Furthermore, patients who carry intranasal S. aureus have a two-to ten-fold increased likelihood of developing a postoperative wound infection due to S. aureus. Identification of patients most at risk of developing an infection is the ultimate goal, however, risk indices must be highly sensitive, specific and accurate. To summarize, the epidemiology of postoperative wound infections remains poorly studied, however, since wound infections contribute significantly to morbidity, mortality and cost, future research is warranted.

Topics: Humans; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Peritoneal dialysis is in widespread use for the treatment of chronic renal failure. Infection is still one of the major complications and can include peritonitis and pericannular problems. The rate of peritonitis is currently 0.5 episodes per patient year with disconnect systems, and there are about 0.4 exit-site infections (ESIs) per patient year. ESI is associated with a high rate of catheter removal and replacement. Staphylococcus aureus is a common cause of peritonitis and accounts for more than half of all ESIs. Nasal carriage of S. aureus is associated with a much higher rate of ESI. Treatment of ESIs is unsatisfactory. The type of exit-site care, however, does influence the rate of infection and prophylaxis with oral rifampicin and local or nasal mupirocin has been claimed to reduce ESIs. A large multicentre double-blind trial of nasal mupirocin has just been completed and preliminary results show a reduction in the incidence of S. aureus-induced ESI. The cost benefits of such a regimen are being evaluated.

Topics: Humans; Nose; Peritoneal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Nasal carriage by health care workers represents an important hospital reservoir of Staphylococcus aureus. Approximately 25% of all hospital-based healthcare workers are stable nasal carriers. Several studies in the US and UK have shown that following treatment of this group with a single 5-day course of intranasal mupirocin, nasal carriage was usually eradicated within 24 hours, and after 12 weeks was only present in 25% of participants. Long-term follow-up in one institution after 52 weeks showed that there were significantly fewer carriers in the mupirocin group than in the group receiving identical placebo. In the same study, between 30% and 50% of those hospital workers who carried S. aureus in their nose, before the start of therapy, were also hand carriers. After treatment, a dramatic reduction in hand carriage of S. aureus was noted, in contrast to no change in the placebo group. After 6 months, the level of hand carriage was still statistically lower in the mupirocin group than in those given placebo. The association between nasal carriage and hand carriage makes it important that health care workers decontaminate their hands effectively between patients. Current evidence suggests, however, that compliance with such control measures is low. Other studies examining the role of S. aureus nasal carriage in the development of post-operative wound infection, have shown that almost half of those isolates recovered from the wound site were present in the nose of the patient pre-operatively. Due to its ability to eliminate nasal carriage of S. aureus, current studies are investigating whether intranasal mupirocin can prevent post-operative wound infections in patients undergoing surgery.

Topics: Cross Infection; Hand; Health Personnel; Humans; Incidence; Methicillin Resistance; Mupirocin; Nose; Staphylococcal Infections; Surgical Wound Infection; United States

Staphylococcus aureus infections remain a major cause of morbidity in hemodialysis patients. Chronic dialysis patients are more prone to staphylococcal infections because of their decreased immunity, increased skin colonization by staphylococci, and the multiple needle punctures required for dialysis. The source of the staphylococci is the anterior nares. Elimination of staphylococcal nasal carriage results in a significantly lower infection rate. Selected clinical studies of topical and oral therapy for eradication of staphylococcal nasal carriage are reviewed. Rifampin has been the most consistently efficacious agent, although emergence of resistance is a potential problem. Trials utilizing newer topical and oral agents for prophylactic eradication of S aureus from the nose are indicated. Promising antibiotics include topical mupirocin, the oral quinolones, and clindamycin.

Topics: Anti-Bacterial Agents; Drug Resistance, Microbial; Humans; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Toxins; Blood; Carrier State; Drug Resistance, Microbial; Humans; Nose; Rifampin; Sepsis; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus; Stevens-Johnson Syndrome; Teichoic Acids

Topics: Acid-Base Equilibrium; Agglutinins; Animals; Antibody Formation; Bacterial Infections; Blood Bactericidal Activity; Blood Glucose; Body Weight; Diabetes Complications; Diabetes Mellitus; Erythrasma; Glucose Tolerance Test; Humans; Ketones; Leprosy; Leukocytosis; Nose; Phagocytosis; Rats; Skin; Skin Diseases, Infectious; Staphylococcal Infections; Urinary Tract Infections

Topics: Acne Vulgaris; Animals; Bacteria; Celiac Disease; Cholic Acids; Colonic Neoplasms; Dental Caries; Digestive System; Endocarditis, Bacterial; Humans; Immunity; Mouth; Nose; Pharynx; Propionibacterium acnes; Skin; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus

Successful decolonisation of nasal Staphylococcus aureus (SA) carriage by mupirocin is limited by increasing drug resistance. This randomised, open-label, phase 1 study compared the safety and local tolerability of two nasal formulations of XF-73, a novel porphyrinic antibacterial with rapid intrinsic activity against SA.. The study was performed in 60 healthy adults. In Part 1, eight non-SA carriers were randomised to groups of four subjects each and were treated with XF-73 concentrations of 0.5mg/g 2% gel or 2.0mg/g 2% gel. In Part 2, 52 persistent SA carriers were randomised to groups of 13 subjects each and were treated with XF-73 concentrations of 0.5mg/g 2% gel, 2.0mg/g 2% gel, 0.5mg/g 4% gel or 4% viscosified placebo gel. Plasma pharmacokinetic and pharmacodynamic studies were performed. Antistaphylococcal activity was assessed as the presence/absence of SA and by quantification of colonisation using a semiquantitative scale (SA score).. 56 subjects (8/8 from Part 1 and 48/52 from Part 2) completed the study, with 47/60 comprising the pharmacokinetic population and 48/60 the pharmacodynamic population. There was no measurable systemic absorption of XF-73. XF-73 treatment was associated with rapid reduction in SA score in all subjects. The most common treatment-emergent adverse events (TEAEs) were rhinorrhoea and nasal dryness (15.5% each in Parts 1 and 2). TEAEs were mild and resolved spontaneously.. XF-73 was well tolerated with minimal side effects at doses of 0.5mg/g 2% gel and 2.0mg/g 2% gel. These findings support further development of XF-73.

Topics: Adult; Anti-Bacterial Agents; Humans; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

Sequential methicillin-resistant

Topics: Anti-Bacterial Agents; Bacterial Load; Carrier State; Drug Resistance, Multiple, Bacterial; Humans; Longitudinal Studies; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Mupirocin; Nose; Staphylococcal Infections

The aim of this study was to evaluate whether chronic nasal carriage of Staphylococcus aureus (SA) is related to relapses in patients with newly diagnosed ANCA-associated vasculitis (AAV).. In two clinical trials (n = 200), for early systemic (n = 83) and generalized (n = 117) AAV, nasal swabs were obtained monthly and at the time of a relapse. Chronic nasal SA carriage (CNSAC) was defined as ⩾ 75% of cultures being SA positive, with non-carriers being SA negative in all cultures and remaining patients being intermittent carriers. Fifty-five of 200 (27.5%) patients received prophylactic trimethoprim/sulfamethoxazole (T/S) against Pneumocystis jirovecii .. Of the total AAV patients, 24/200 (12%) were chronic, 102/200 (51%) intermittent and 74/200 (37%) non-carriers. Of 65 relapsing patients, 10/24 (41.7%) were chronic, 32/102 (31.4%) intermittent and 23/74 (31.1%) non-carriers (P = 0.59). For all AAV patients, CNSAC was not associated with an increased relapse risk [odds ratio (OR) = 1.57, 95% CI: 0.66, 3.76; P = 0.31]. However, 23/24 chronic carriers had granulomatosis with polyangiitis (GPA). In the 73 patients with generalized GPA (hazard ratio = 4.10, 95% CI: 1.37, 12.25; P = 0.01) and the 78 patients with early systemic GPA during immunosuppression (hazard ratio = 2.73, 95% CI: 0.95, 7.87; P = 0.06), relapse rates were higher for chronic SA carriers. Prophylactic T/S was not associated with a reduced relapse risk (OR = 0.71, 95% CI: 0.36, 1.41; P = 0.33). Nevertheless, prophylactic T/S reduced CNSAC (OR = 0.19, 95% CI: 0.04, 0.91; P = 0.04).. The frequency of CNSAC in newly diagnosed GPA paralleled that in the general population. This subset of GPA patients (23/151, 15.2%) has a high relapse rate despite immunosuppression and prophylactic T/S treatment, requiring further investigations on pathogenesis and therapy.

Topics: Adolescent; Adult; Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Chronic Disease; Female; Granulomatosis with Polyangiitis; Humans; Male; Middle Aged; Nose; Prospective Studies; Recurrence; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Staphylococcus aureus (S. aureus) is a common pathogen in surgical site infections (SSIs). Mupirocin ointment is an effective treatment for nasal carriers. We aimed to investigate whether screening for nasal colonization of S. aureus and treating carriers prior to a cesarean section (CS) decreases the likelihood of SSI.. This is a randomized controlled trial. All participants underwent nasal culture prior to the CS. Nasal carriers of S. aureus were treated with Mupirocin ointment according to a standardized protocol. In the control group, nasal cultures were obtained immediately prior to surgery and carriers were not treated.. We recruited 568 patients. Demographic characteristics were comparable between the groups. S. aureus nasal colonization rates were 20.1% and 14.9% in the intervention and control groups, respectively (p = 0.12). S. aureus eradication rate with Mupirocin treatment was 88%. SSI rates were similar in the intervention and control groups (13.1% versus 12.1%, respectively, p = 0.78) and in treated carriers, untreated carriers, and non-carriers (7.4% versus 13.0% versus 13.1%, respectively, p = 0.69). Previous CS was the only factor found to independently predict SSI (OR 2.5, CI 1.09-5.65 p = 0.029).. Pre-cesarean screening for nasal S. aureus carriage and decolonization does not appear to be an effective intervention in reducing SSI rates.

Topics: Adult; Anti-Bacterial Agents; Carrier State; Cesarean Section; Female; Humans; Mupirocin; Nose; Pregnancy; Pregnancy Trimester, Third; Preoperative Period; Regression Analysis; Staphylococcal Infections; Staphylococcus aureus; Statistics, Nonparametric; Surgical Wound Infection

Smoking increases hospitalization and healthcare-associated infection. Our primary aim of this pilot, randomized-controlled trial was to examine the feasibility and acceptability of a tobacco cessation intervention compared with usual care in inpatients. S. aureus carriage, healthcare-associated infections and infections post discharge were exploratory outcomes.. Current inpatient smokers from a university hospital facility were randomized to usual care or a face to face tobacco cessation counseling session where patients' tobacco use and strategies for quitting were discussed. Patient engagement, satisfaction and withdrawal symptoms were measured at 1 week and 12 weeks post discharge. Nasal swabs were collected at enrollment and discharge and assessed for S. aureus colonization. P-values were calculated using Fisher's exact and t-tests were used to compare groups.. For the study's primary outcome, participants reported the intervention as being generally acceptable and reported high overall levels of satisfaction, with a Likert scale score of at least 4/5 for all measures of satisfaction. No subjects utilized free tobacco cessation services after discharge. 83 % of the intervention group and 93 % of the control group smoked at least one cigarette after discharge. Secondary outcomes with regard to infections showed that, at discharge, 12 % of the intervention group (n = 17) and 18 % of the control group (n = 22) tested positive for S. aureus. After 3 months, 9 % of the intervention group developed infection, 41 % visited an emergency room, and 24 % were readmitted within 3 months post-discharge, compared to 27, 32 and 36 % of the control group respectively.. With regards to the primary aim of this study, there were overall high levels of satisfaction with the intervention, indicating good feasibility and acceptance among patients. However, more intensive interventions in hospitalized patients and impact on healthcare-associated infections and post-discharge infections should be explored.

Topics: Adult; Cross Infection; Feasibility Studies; Female; Humans; Inpatients; Male; Middle Aged; Nose; Patient Satisfaction; Pilot Projects; Smoking Cessation; Staphylococcal Infections; Substance Withdrawal Syndrome; Wisconsin

Surgical site infections (SSI) are a serious complication in vascular surgery which may lead to severe morbidity and mortality. Staphylococcus aureus nasal carriage is associated with increased risk for development of SSIs in central vascular surgery. The risk for SSI can be reduced by perioperative eradication of S. aureus carriage in cardiothoracic and orthopedic surgery. This study analyzes the relation between S. aureus eradication therapy and SSI in a vascular surgery population.. A prospective cohort study was performed, including all patients undergoing vascular surgery between February 2013 and April 2015. Patients were screened for S. aureus nasal carriage and, when tested positive, were subsequently treated with eradication therapy. The presence of SSI was recorded based on criteria of the CDC. The control group consisted of a cohort of vascular surgery patients in 2010, who were screened, but received no treatment.. A total of 444 patients were screened. 104 nasal swabs were positive for S. aureus, these patients were included in the intervention group. 204 patients were screened in the 2010 cohort. 51 tested positive and were included in the control group. The incidence of S. aureus infection was 5 out of 51 (9.8%) in the control group versus 3 out of 104 in the eradication group (2.2%; 95% confidence interval 0.02-1.39; P = 0.13). A subgroup analysis showed that the incidence of S. aureus infection was 3 out of 23 (13.0%) in the control group in central reconstructive surgery versus 0 out of 44 in the intervention group (P = 0.074). The reduction of infection pressure by S. aureus was stronger than the reduction of infection pressure by other pathogens (exact maximum likelihood estimation; OR = 0.0724; 95% CI: 0.001-0.98; p = 0.0475).. S. aureus eradication therapy reduces the infection pressure of S. aureus, resulting in a reduction of SSIs caused by S. aureus.

Topics: Aged; Female; Humans; Male; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Vascular Surgical Procedures

Previous studies suggested that a bundled intervention was associated with lower rates of Staphylococcus aureus surgical site infections (SSIs) among patients having cardiac or orthopedic operations.. To evaluate whether the implementation of an evidence-based bundle is associated with a lower risk of S. aureus SSIs in patients undergoing cardiac operations or hip or knee arthroplasties.. Twenty hospitals in 9 US states participated in this pragmatic study; rates of SSIs were collected for a median of 39 months (range, 39-43) during the preintervention period (March 1, 2009, to intervention) and a median of 21 months (range, 14-22) during the intervention period (from intervention start through March 31, 2014).. Patients whose preoperative nares screens were positive for methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) were asked to apply mupirocin intranasally twice daily for up to 5 days and to bathe daily with chlorhexidine-gluconate (CHG) for up to 5 days before their operations. MRSA carriers received vancomycin and cefazolin or cefuroxime for perioperative prophylaxis; all others received cefazolin or cefuroxime. Patients who were MRSA-negative and MSSA-negative bathed with CHG the night before and morning of their operations. Patients were treated as MRSA-positive if screening results were unknown.. The primary outcome was complex (deep incisional or organ space) S. aureus SSIs. Monthly SSI counts were analyzed using Poisson regression analysis.. After a 3-month phase-in period, bundle adherence was 83% (39% full adherence; 44% partial adherence). Overall, 101 complex S. aureus SSIs occurred after 28,218 operations during the preintervention period and 29 occurred after 14,316 operations during the intervention period (mean rate per 10,000 operations, 36 for preintervention period vs 21 for intervention period, difference, -15 [95% CI, -35 to -2]; rate ratio [RR], 0.58 [95% CI, 0.37 to 0.92]). The rates of complex S. aureus SSIs decreased for hip or knee arthroplasties (difference per 10,000 operations, -17 [95% CI, -39 to 0]; RR, 0.48 [95% CI, 0.29 to 0.80]) and for cardiac operations (difference per 10,000 operations, -6 [95% CI, -48 to 8]; RR, 0.86 [95% CI, 0.47 to 1.57]).. In this multicenter study, a bundle comprising S. aureus screening, decolonization, and targeted prophylaxis was associated with a modest, statistically significant decrease in complex S. aureus SSIs.

Topics: Administration, Intranasal; Adolescent; Adult; Aged; Aged, 80 and over; Antibiotic Prophylaxis; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Cardiac Surgical Procedures; Cefazolin; Cefuroxime; Chlorhexidine; Drug Therapy, Combination; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Vancomycin; Young Adult

Fluoroquinolone-resistant staphylococci (FQRS) are primarily selected in the nasal microbiota during fluoroquinolone (FQ) treatment. To gain insight into the dynamics of the emergence of FQRS, 49 hospitalised patients (HPs) and 62 community patients (CPs) treated with FQs were studied. Nasal swabs were collected before (T0), at the end of (T1) and 1 month after (T2) FQ treatment. FQRS were identified by mass spectrometry. Antibiotic resistance was determined. Pre- and post-exposure staphylococci populations were compared phenotypically and by MLST to determine the origin of FQRS. At T0, 33/49 HPs (67%) and 24/62 CPs (39%) carried FQRS (OR=3.3, 95% CI: 1.4-7.9; P<0.001). Among patients with no FQRS at T0, 15/16 HPs (94%) and 16/38 CPs (42%) had FQRS detected at T1 and/or T2 (OR=19.6, 95% CI: 2.5-902; P<0.001). Among FQRS having emerged, co-resistance to meticillin was detected in 87% and 82% of HPs and CPs, respectively. No selection of resistance emerging from the initial microbiota was evidenced. FQRS showed decreased species diversity in favour of Staphylococcus haemolyticus and Staphylococcus epidermidis. As a consequence of FQ treatment, acquisition of FQRS in the nasal microbiota is frequent in the community and almost inevitable in hospitals. Acquisition from extranasal sites prevails. A restriction in species diversity in favour of more pathogenic and resistant species occurs. This highlights the major impact of FQ treatment on nasal microbiota, the role of the ecological environment in the emergence of FQRS, and the high-risk of dissemination of resistant staphylococci.

Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Fluoroquinolones; Humans; Microbial Sensitivity Tests; Microbiota; Multilocus Sequence Typing; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus epidermidis; Staphylococcus haemolyticus

A limitation of both culture-based and molecular methods of screening for staphylococcal infection is that current tests determine only the presence or absence of colonization with no information on the colonizing strain type. A technique that couples polymerase chain reaction to mass spectrometry (PCR/ESI-MS) has recently been developed and an assay validated to identify and genotype S. aureus and coagulase-negative staphylococci (CoNS).. This study was conducted to determine the rates, risk factors, and molecular genotypes of colonizing Staphylococcus aureus in adult patients presenting to an inner-city academic emergency department. Participants completed a structured questionnaire to assess hospital and community risks for infection with methicillin-resistant S. aureus (MRSA). Nasal swabs were analyzed by PCR/ESI-MS to identify and genotype S. aureus and CoNS.. Of 200 patients evaluated, 59 were colonized with S. aureus; 27 of these were methicillin-resistant strains. Twenty-four of the 59 S. aureus carriers were co-colonized with a CoNS and 140 of the 200 patients were colonized exclusively with CoNS. The molecular genotypes of the 59 S. aureus strains were diverse; 21 unique molecular genotypes belonging to seven major clonal complexes were identified. Eighty-five of 200 patients carried strains with high-level mupirocin resistance. Of these eighty-five participants, 4 were colonized exclusively with S. aureus, 16 were co-colonized with S. aureus and CoNS, and 65 were colonized exclusively with CoNS.. The prevalence of S. aureus and methicillin-resistant S. aureus colonization in a random sample of patients seeking care in Emergency Department was 29.5% and 13.5%, respectively. A substantial fraction of the S. aureus-colonized patients were co-colonized with CoNS and high-level mupirocin-resistant CoNS. Determining the molecular genotype of S. aureus during intake screening may prove valuable in the future if certain molecular genotypes become associated with increased infection risk.

Topics: Adolescent; Adult; Emergency Service, Hospital; Female; Genotype; Genotyping Techniques; Humans; Male; Maryland; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mupirocin; Nose; Polymerase Chain Reaction; Prevalence; Prospective Studies; Risk Factors; Spectrometry, Mass, Electrospray Ionization; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Treatment of Staphylococcus aureus colonization before surgery reduces risk of surgical site infection (SSI). The regimen of nasal mupirocin ointment and topical chlorhexidine gluconate is effective, but cost and patient compliance may be a barrier. Nasal povidone-iodine solution may provide an alternative to mupirocin.. We conducted an investigator-initiated, open-label, randomized trial comparing SSI after arthroplasty or spine fusion in patients receiving topical chlorhexidine wipes in combination with either twice daily application of nasal mupirocin ointment during the 5 days before surgery or 2 applications of povidone-iodine solution into each nostril within 2 hours of surgical incision. The primary study end point was deep SSI within the 3 months after surgery.. In the modified intent-to-treat analysis, a deep SSI developed after 14 of 855 surgical procedures in the mupirocin group and 6 of 842 surgical procedures in the povidone-iodine group (P = .1); S. aureus deep SSI developed after 5 surgical procedures in the mupirocin group and 1 surgical procedure in the povidone-iodine group (P = .2). In the per protocol analysis, S. aureus deep SSI developed in 5 of 763 surgical procedures in the mupirocin group and 0 of 776 surgical procedures in the povidone-iodine group (P = .03).. Nasal povidone-iodine may be considered as an alternative to mupirocin in a multifaceted approach to reduce SSI.. ClinicalTrials.gov identifier: NCT01313182.

Topics: Administration, Intranasal; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Antibiotic Prophylaxis; Arthroplasty; Female; Humans; Intention to Treat Analysis; Male; Middle Aged; Mupirocin; Nose; Ointments; Povidone-Iodine; Spinal Fusion; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Young Adult

We tested infection prevention strategies to limit exposure of long-term care facility residents to drug-resistant pathogens in a prospective, cluster randomized 2-year trial involving 3 long-term care facilities (LTCFs) using methicillin-resistant Staphylococcus aureus (MRSA) as a model. We hypothesized that nasal MRSA surveillance using rapid quantitative polymerase chain reaction and decolonization of carriers would successfully lower overall MRSA colonization. In year 1, randomly assigned intervention units received decolonization with nasal mupirocin and chlorhexidine bathing and enhanced environmental cleaning with bleach every 4 months. Newly admitted MRSA nares-positive residents were decolonized on admission. Control units were screened but not decolonized. All units received periodic bleach environmental cleaning and instruction on hand hygiene. In year 2, all units followed intervention protocol caused by failure of the cluster randomized approach to sufficiently segregate patients. MRSA colonization was monitored using point prevalence testing every 4-6 months. Colonization status at admission and discharge was performed 1 quarter per year to determine acquisition. Fisher exact test was used for statistical analysis. Baseline MRSA colonization rate was 16.64%. In year 1, the colonization rate of intervention units was 11.61% (P = .028) and 17.85% in control units (P = .613) compared with baseline. Intervention unit rate difference compared with the controls was significant (P = .001). In year 2, the colonization rate was 10.55% (P < .001) compared with baseline. The transmission rates were 1.66% and 3.52% in years 1 and 2, respectively (P = .034). The planned interventions of screening and decolonization were successful at lowering MRSA colonization.

Topics: Anti-Bacterial Agents; Carrier State; Chlorhexidine; Cross Infection; Disinfectants; Infection Control; Long-Term Care; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Nursing Homes; Prospective Studies; Sodium Hypochlorite; Staphylococcal Infections

Impetigo is caused by both Streptococcus pyogenes and Staphylococcus aureus; the relative contributions of each have been reported to fluctuate with time and region. While S. aureus is reportedly on the increase in most industrialised settings, S. pyogenes is still thought to drive impetigo in endemic, tropical regions. However, few studies have utilised high quality microbiological culture methods to confirm this assumption. We report the prevalence and antimicrobial resistance of impetigo pathogens recovered in a randomised, controlled trial of impetigo treatment conducted in remote Indigenous communities of northern Australia.. Each child had one or two sores, and the anterior nares, swabbed. All swabs were transported in skim milk tryptone glucose glycogen broth and frozen at -70°C, until plated on horse blood agar. S. aureus and S. pyogenes were confirmed with latex agglutination.. From 508 children, we collected 872 swabs of sores and 504 swabs from the anterior nares prior to commencement of antibiotic therapy. S. pyogenes and S. aureus were identified together in 503/872 (58%) of sores; with an additional 207/872 (24%) sores having S. pyogenes and 81/872 (9%) S. aureus, in isolation. Skin sore swabs taken during episodes with a concurrent diagnosis of scabies were more likely to culture S. pyogenes (OR 2.2, 95% CI 1.1 - 4.4, p = 0.03). Eighteen percent of children had nasal carriage of skin pathogens. There was no association between the presence of S. aureus in the nose and skin. Methicillin-resistance was detected in 15% of children who cultured S. aureus from either a sore or their nose. There was no association found between the severity of impetigo and the detection of a skin pathogen.. S. pyogenes remains the principal pathogen in tropical impetigo; the relatively high contribution of S. aureus as a co-pathogen has also been confirmed. Children with scabies were more likely to have S. pyogenes detected. While clearance of S. pyogenes is the key determinant of treatment efficacy, co-infection with S. aureus warrants consideration of treatment options that are effective against both pathogens where impetigo is severe and prevalent.. This trial is registered; ACTRN12609000858291 .

Topics: Adolescent; Australia; Carrier State; Child; Child, Preschool; Coinfection; Female; Humans; Impetigo; Infant; Male; Methicillin Resistance; Nose; Population Groups; Prevalence; Respiratory Tract Infections; Scabies; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Streptococcus pyogenes; Treatment Outcome

Surgical site infection (SSI) can be a problematic complication of Mohs micrographic surgery (MMS). Previous reports have cited nasal Staphylococcus aureus (S. aureus) carriage as a risk factor for SSI, but none thus far in dermatologic surgery.. The aim was to determine the difference in infection rates between nasal carriers of S. aureus and non-carriers, and whether decolonisation with intranasal mupirocin ointment and chlorhexidine wash would reduce the infection rate in nasal carriers.. In all, 738 patients presenting for MMS at the Oxford Day Surgery and Dermatology underwent a nasal swab to determine their S. aureus carriage status. S. aureus carriers were randomised for decolonisation with intranasal mupirocin ointment and chlorhexidine body wash. Non-carriers were untreated. All patients were followed up for SSI.. The rate of SSI was 11 per cent in untreated S. aureus carriers, 4 per cent in treated carriers, and 3 per cent in non-carriers. The difference in infection rate between carriers and non-carriers was significant (P < 0.001). The difference between treated and untreated carriers was also significant (P = 0.05).. Nasal S. aureus carriage is an important risk factor for SSI in MMS, conferring an over threefold increase in SSI risk. A pre-operative nasal swab provides a simple and effective risk stratification tool. The use of a topical decolonisation regimen reduces the infection rate in carriers to a level approaching non-carriers without exposure to systemic antibiotics.

Topics: Aged; Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Chlorhexidine; Female; Humans; Male; Middle Aged; Mohs Surgery; Mupirocin; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Methicillin-resistant Staphylococcus aureus (MRSA) pulsed-field type (PFT) USA300 causes skin and soft tissue infections in military recruits and invasive disease in hospitals. Chlorhexidine gluconate (CHG) is used to reduce MRSA colonization and infection. The impact of CHG on the molecular epidemiology of MRSA is not known.. To evaluate the impact of 2% CHG-impregnated cloths on the molecular epidemiology of MRSA colonization.. Cluster-randomized, double-blind, controlled trial.. Marine Officer Candidate School, Quantico, Virginia, in 2007.. Military recruits.. Thrice-weekly application of CHG-impregnated or control (Comfort Bath; Sage) cloths over the entire body.. Baseline and serial (every 2 weeks) nasal and/or axillary swab samples were assessed for MRSA colonization. Molecular analysis was performed with pulsed-field gel electrophoresis.. During training, 77 subjects (4.9%) acquired MRSA, 26 (3.3%) in the CHG group and 51 (6.5%) in the control group (P=.004). When analyzed for PFT, 24 subjects (3.1%) in the control group but only 6 subjects (0.8%) in the CHG group (P=.001) had USA300. Of the 167 colonizing isolates recovered from 77 subjects, 99 were recovered from the control group, including USA300 (40.4%), USA800 (38.4%), USA1000 (12.1%), and USA100 (6.1%), and 68 were recovered from the CHG group, including USA800 (51.5%), USA100 (23.5%), and USA300 (13.2%).. CHG decreased the transmission of MRSA--more specifically, USA300--among military recruits. In addition, USA300 and USA800 outcompeted other MRSA PFTs at incident colonization. Future studies should evaluate the broad-based use of CHG to decrease transmission of USA300 in hospital settings.

Topics: Anti-Infective Agents, Local; Axilla; Carrier State; Chlorhexidine; Community-Acquired Infections; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Humans; Methicillin-Resistant Staphylococcus aureus; Military Personnel; Molecular Epidemiology; Molecular Typing; Nose; Staphylococcal Infections; United States

Chronic rhinosinusitis (CRS) recalcitrant to surgery is a frustrating clinical entity. Recently, mupirocin sinonasal rinses have been suggested as an efficacious treatment alternative in these patients where Staphylococcus aureus infection is demonstrated. To our knowledge, how best to treat this S aureus reservoir has not been previously evaluated in a double-blinded, randomized, placebo-controlled trial.. Prospective, double-blinded, placebo-controlled study.. Twenty-five S aureus-positive CRS patients with persistent sinonasal infection despite endoscopic sinus surgery received either a 1-month, twice-daily treatment course of mupirocin sinonasal rinses (MUP) or saline rinses (CON). The primary outcome was S aureus-culture negativity at the conclusion of treatment; secondary rhinological outcomes included subjective and objective measures of rhinosinusitis.. Twenty-two patients satisfactorily completed the treatment period. Of CON patients, 0/13 (0.0%) returned an S aureus-negative sinonasal culture at 1 month, compared to 8/9 (88.9%) of MUP patients (P < .01). Improvements in rhinological outcomes observed in MUP patients following treatment were not subsequently evident when these patients were followed up at a delayed assessment 2 to 6 months after completing treatment.. Mupirocin sinonasal rinses are an effective short-term anti-S aureus treatment in surgically recalcitrant CRS as assessed by microbiological and selected rhinological outcomes, although the latter improvements may not be durable with time.

Topics: Administration, Intranasal; Adult; Anti-Bacterial Agents; Chronic Disease; Double-Blind Method; Female; Humans; Male; Middle Aged; Mupirocin; Nasal Lavage; Nose; Rhinitis; Sinusitis; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

To compare an interventional protocol with a standard protocol for preventing the acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in the intensive care unit (ICU).. Prospective, randomized, controlled, parallel-group, nonblinded clinical trial.. Medical ICUs of 2 French university hospitals.. Five hundred adults with an expected length of stay in the ICU greater than 48 hours.. For the intervention group, the protocol required repeated MRSA screening, contact and droplet isolation precautions for patients at risk for MRSA at ICU admission and for MRSA-positive patients, and decontamination with nasal mupirocin and chlorhexidine body wash for MRSA-positive patients. For the standard group, the standard precautions protocol was used, and the results of repeated MRSA screening in the standard group were not communicated to investigators.. MRSA acquisition rate in the ICU. An audit was conducted to assess compliance with hygiene and isolation precautions.. In the intent-to-treat analysis ([Formula: see text]), the MRSA acquisition rate in the ICU was similar in the standard (13 [5.3%] of 243) and intervention (16 [6.5%] of 245) groups ([Formula: see text]). The audit showed that the overall compliance rate was 85.5% in the standard group and 84.1% in the intervention group ([Formula: see text]), although compliance was higher when isolation precautions were absent than when they were in place (88.2% vs 79.1%; [Formula: see text]). MRSA incidence rates were higher without isolation precautions (7.57‰) than with isolation precautions (2.36‰; [Formula: see text]).. Individual allocation to MRSA screening, isolation precautions, and decontamination do not provide individual benefit in reducing MRSA acquisition, compared with standard precautions, although the collective risk was lower during the periods of isolation.. Clinicaltrials.gov identifier: NCT00151606.

Topics: Aged; Anti-Bacterial Agents; Anti-Infective Agents, Local; Chlorhexidine; Cross Infection; Female; France; Guideline Adherence; Hospitals, Teaching; Humans; Infection Control; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mupirocin; Nose; Patient Isolation; Staphylococcal Infections

The multicenter, cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was performed in 18 U.S. adult intensive care units (ICUs). It evaluated the effectiveness of infection control strategies to reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission.. Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis.. Of 5,512 ICU patient admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a nares sample culture result that was positive for MRSA. A total of 210 (34%) of 626 available isolates were selected for molecular typing by weighted random sampling. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USA100 clone, 26 (12%) were USA300, 12 (6%) were USA500, 8 (4%) were USA800, and 17 (8%) were other MRSA genotypes. In a multivariate analysis, patients who were colonized with a CA-MRSA genotype (USA300, USA400, or USA1000) were less likely to have been hospitalized during the previous 12 months (PR [prevalence ratio], 0.39 [95% confidence interval (CI), 0.21-0.73]) and were less likely to be older (PR, 0.97 [95% CI, 0.95-0.98] per year) compared with patients who were colonized with a healthcare-associated (HA)-MRSA genotype.. CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the United States. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Community-Acquired Infections; Cross Infection; Female; Genotype; Humans; Infection Control; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Patient Admission; Prevalence; Risk Factors; Staphylococcal Infections; United States; Young Adult

The aim of this cluster randomised controlled trial was to test the impact of an infection control education and training programme on meticillin-resistant Staphylococcus aureus (MRSA) prevalence in nursing homes. Nursing homes were randomised to intervention (infection control education and training programme; N=16) or control (usual practice continued; N=16). Staff in intervention homes were educated and trained (0, 3 and 6 months) in the principles and implementation of good infection control practice with infection control audits conducted in all sites (0, 3, 6 and 12 months) to assess compliance with good practice. Audit scores were fed back to nursing home managers in intervention homes, together with a written report indicating where practice could be improved. Nasal swabs were taken from all consenting residents and staff at 0, 3, 6 and 12 months. The primary outcome was MRSA prevalence in residents and staff, and the secondary outcome was a change in infection control audit scores. In all, 793 residents and 338 staff were recruited at baseline. MRSA prevalence did not change during the study in residents or staff. The relative risk of a resident being colonised with MRSA in an intervention home compared with a control home at 12 months was 0.99 (95% confidence interval: 0.69, 1.42) after adjustment for clustering. Mean infection control audit scores were significantly higher in the intervention homes (82%) compared with the control homes (64%) at 12 months (P<0.0001). Consideration should be given to other approaches which may help to reduce MRSA in this setting.

Topics: Aged; Aged, 80 and over; Carrier State; Cross Infection; Education, Medical; Female; Guideline Adherence; Humans; Infection Control; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Nursing Homes; Prevalence; Staphylococcal Infections

Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.

Topics: Bacterial Proteins; beta-Defensins; Biofilms; Female; Humans; Male; Nose; Odds Ratio; Serine Proteases; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis; Superinfection; Young Adult

Staphylococcus aureus is a common cause of postoperative wound infections, and nasal colonization by this organism is an important factor in the development of infections. Treatment with mupirocin can eradicate the organism in the short term, and prophylactic treatment of colonized patients may prevent postoperative S. aureus infections. A double-blind, randomized, placebo-controlled trial was performed to determine whether nasal mupirocin administered pre-operatively to S. aureus carriers reduces the rates of sternal and leg wound infections after cardiac surgery. The study enrolled 263 patients with nasal S. aureus undergoing elective cardiac surgery at St. Michael's Hospital, Toronto, Canada. Patients were assessed for infections in the immediate postoperative period and two months later. Two hundred and fifty-seven patients were included in the intention-to-treat analysis and re-analysed according to the actual treatment applied. Wound infections occurred in 17 (13.5%) mupirocin recipients and 11 (9.1%) placebo recipients (P=0.319), with seven (5.4%) and six (4.7%) sternal infections, respectively. Two (1.6%) wound infections were acquired postoperatively in the mupirocin group, neither of which were caused by S. aureus. The placebo group had three (2.4%) nosocomial wound infections, with two (1.6%) S. aureus bacteraemias (P=0.243). Among patients receiving mupirocin, 106 (81.5%) cleared S. aureus compared with 59 (46.5%) patients receiving placebo (P<0.0001). There was no significant difference between intention-to-treat and actual treatment groups. Prophylactic intranasal mupirocin administered to S. aureus carriers did not reduce the rates of overall surgical site infections by S. aureus, and only showed a trend towards decreased incidence of nosocomial S. aureus infections.

Topics: Administration, Cutaneous; Anti-Bacterial Agents; Carrier State; Coronary Artery Bypass; Cross Infection; Double-Blind Method; Female; Humans; Male; Middle Aged; Mupirocin; Nose; Preoperative Care; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Treatment Outcome

Nasal carriage of Staphylococcus aureus is an important risk factor for S. aureus infections. Mupirocin nasal ointment is presently the treatment of choice for decolonizing the anterior nares. However, recent clinical trials show limited benefit from mupirocin prophylaxis in preventing nosocomial S. aureus infections, probably due to (re)colonization from extranasal carriage sites. Therefore, we studied the effectiveness of mupirocin nasal ointment treatment on the dynamics of S. aureus nasal and extranasal carriage. Twenty noncarriers, 26 intermittent carriers, and 16 persistent carriers had nasal, throat, and perineum samples taken 1 day before and 5 weeks after mupirocin treatment (twice daily for 5 days) and assessed for growth of S. aureus. The identities of cultured strains were assessed by restriction fragment length polymorphisms of the coagulase and protein A genes. The overall carriage rate (either nasal, pharyngeal, or perineal carrier or a combination) was significantly reduced after mupirocin treatment from 30 to 17 carriers (P = 0.003). Of the 17 carriers, 10 (60%) were still colonized with their old strain, 6 (35%) were colonized with an exogenous strain, and 1 (5%) was colonized with both. Two noncarriers became carriers after treatment. The acquisition of exogenous strains after mupirocin treatment is a common phenomenon. The finding warrants the use of mupirocin only in proven carriers for decolonization purposes. Mupirocin is effective overall in decolonizing nasal carriers but less effective in decolonizing extranasal sites.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Carrier State; Humans; Mupirocin; Nose; Ointments; Perineum; Pharynx; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

Staphylococcus aureus nasal carriage is a major risk factor for nosocomial S. aureus infection. Studies show that intranasal mupirocin can prevent nosocomial surgical site infections. No data are available on the efficacy of mupirocin in nonsurgical patients.. To assess the efficacy of mupirocin prophylaxis in preventing nosocomial S. aureus infections in nonsurgical patients.. Randomized, double-blind, placebo-controlled trial.. 3 tertiary care academic hospitals and 1 nonacademic hospital.. 1602 culture-proven S. aureus carriers hospitalized in nonsurgical departments.. Therapy with mupirocin 2% nasal ointment (n = 793) or placebo ointment (n = 809), twice daily for 5 days, started 1 to 3 days after admission.. Nosocomial S. aureus infections according to defined criteria, in-hospital mortality, duration of hospitalization, and time to nosocomial S. aureus infection. Staphylococcus aureus isolates were genotyped to assess whether infection was caused by endogenous strains.. The mupirocin and placebo groups did not statistically differ in the rates of nosocomial S. aureus infections (mupirocin, 2.6%; placebo, 2.8%; risk difference, 0.2 percentage point [95% CI, -1.5 to 1.9 percentage points]), mortality (mupirocin, 3.0%; placebo, 2.8%; risk difference, -0.2 percentage point [CI, -1.9 to 1.5 percentage points]), or duration of hospitalization (median for both, 8 days). However, time to nosocomial S. aureus infection was decreased in the mupirocin group from 12 to 25 days (P > 0.2). A total of 77% of S. aureus nosocomial infections were endogenous.. A few infections in both groups may have been missed because investigators assessed a patient for infection only if microbiology culture results were positive for S. aureus.. Routine culture for S. aureus nasal carriage at admission and subsequent mupirocin application does not provide effective prophylaxis against nosocomial S. aureus infections in nonsurgical patients.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Cross Infection; Double-Blind Method; Female; Genotype; Hospital Mortality; Humans; Length of Stay; Male; Middle Aged; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

Nonbullous impetigo is a common skin infection in children and is frequently caused by Staphylococcus aureus. Staphylococcal toxins and especially exfoliative toxin A are known mediators of bullous impetigo in children. It is not known whether this is also true for nonbullous impetigo. We set out to analyze clonality among clinical isolates of S. aureus from children with nonbullous impetigo living in a restricted geographical area in The Netherlands. We investigated whether staphylococcal nasal carriage and the nature of the staphylococcal strains were associated with the severity and course of impetigo. Bacterial isolates were obtained from the noses and wounds of children suffering from impetigo. Strains were genetically characterized by pulsed-field gel electrophoresis-mediated typing and binary typing, which was also used to assess toxin gene content. In addition, a detailed clinical questionnaire was filled in by each of the participating patients. Staphylococcal nasal carriage seems to predispose the patients to the development of impetigo, and 34% of infections diagnosed in the Rotterdam area are caused by one clonal type of S. aureus. The S. aureus strains harbor the exfoliative toxin B (ETB) gene as a specific virulence factor. In particular, the numbers (P = 0.002) and sizes (P < 0.001) of the lesions were increased in patients infected with an ETB-positive strain. Additional predictors of disease severity and development could be identified. The presence of a staphylococcal plasmid encoding multiple antibiotic resistance traits, as detected by binary typing, was associated with a reduction in the cure rate. Our results recognize that a combination of staphylococcal virulence and resistance genes rather than a single gene determines the development and course of nonbullous impetigo. The identification of these microbial genetic markers, which are predictive of the severity and the course of the disease, will facilitate guided individualized antimicrobial therapy in the future.

Topics: Anti-Bacterial Agents; Bacterial Toxins; Child; Child, Preschool; Drug Resistance, Multiple, Bacterial; Exfoliatins; Exotoxins; Fusidic Acid; Genetic Markers; Humans; Impetigo; Leukocidins; Nose; Plasmids; Severity of Illness Index; Staphylococcal Infections; Staphylococcus aureus; Virulence

Staphylococcus aureus is the agent of community-acquired and nosocomial infections. Twenty to 35% of the population permanently carries it in the nose and oropharynx, and additional 50%, carries it intermittently. Topical calcium mupirocin is an antibacterial agent against Staphylococcus aureus recommended to eradicate nasal and hand colonization in patients and health care workers. The prevalence of nasal S. aureus was determined in patients undergoing cardiovascular surgery. In addition, the effect of mupirocine on the number of carriers and rate of nosocomial infections was evaluated. An experimental prospective study was undertaken with two groups of patients: one treated with mupirocin (n = 96), and the other without treatment (n = 95). Tests for presence of nasal S. aureus and nosocomial infections were conducted in all patients. A 34% prevalence of S. aureus carriers was found. A decrease of the prevalence was found in both treated (87%) and untreated patients (33%), but in significantly different proportions (p = 0.0002, RR = 0.22, 95%CI = 0.09-0.054). This result demonstrated the effectiveness of a mupirocin treatment program to decrease numbers of nasal carriers. With regard to nosocomial infection, S. aureus prevalence was 3.6%, occurring mostly in control patients (6 of 7). Total nosocomial infection prevalence was 17.3%, evenly distributed in treated and untreated patients. This suggested that mupirocin use did not decrease the number of nosocomial infections.

Topics: Administration, Intranasal; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Cross Infection; Female; Humans; Male; Middle Aged; Mupirocin; Nasal Mucosa; Nose; Prevalence; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

Patients with nasal carriage of Staphylococcus aureus have an increased risk of surgical-site infections caused by that organism. Treatment with mupirocin ointment can reduce the rate of nasal carriage and may prevent postoperative S. aureus infections.. We conducted a randomized, double-blind, placebo-controlled trial to determine whether intranasal treatment with mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections.. Of 4030 enrolled patients who underwent general, gynecologic, neurologic, or cardiothoracic surgery, 3864 were included in the intention-to-treat analysis. Overall, 2.3 percent of mupirocin recipients and 2.4 percent of placebo recipients had S. aureus infections at surgical sites. Of the 891 patients (23.1 percent of the 3864 who completed the study) who had S. aureus in their anterior nares, 444 received mupirocin and 447 received placebo. Among the patients with nasal carriage of S. aureus, 4.0 percent of those who received mupirocin had nosocomial S. aureus infections, as compared with 7.7 percent of those who received placebo (odds ratio for infection, 0.49; 95 percent confidence interval, 0.25 to 0.92; P=0.02).. Prophylactic intranasal application of mupirocin did not significantly reduce the rate of S. aureus surgical-site infections overall, but it did significantly decrease the rate of all nosocomial S. aureus infections among the patients who were S. aureus carriers.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Cross Infection; Double-Blind Method; Female; Humans; Male; Middle Aged; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

To evaluate the role of normal flora in the nares in preventing Staphylococcus aureus colonization, we conducted a replacement study in vivo. Staphylococcus epidermidis (rate of colonization: 100%), various species of corynebacteria (52.5%) and S. aureus (25.%) were the major bacterial inhabitants in the nares of 156 healthy volunteers. The low incidence of S. aureus colonization in the carriers with corynebacteria (8.5%), compared to non-carriers (44. 5%) indicated the possibility of competition for survival between S. aureus and corynebacteria. To confirm this hypothesis, we artificially implanted a strain of Corynebacterium sp (API Coryne bioprofile; 5100304), denoted as Co304 into the nares of 17 S. aureus carriers. S. aureus was completely eradicated in 71% of carriers by up to 15 inoculations of Co304. However, similar doses of 0.9% NaCl or S. epidermidis into the nares of 10 volunteers did not eradicate S. aureus. No bacteriocin-like activity against S. aureus was detectable, even after mitomycin C stimulation of Co304. Thus Co304 interfered with S. aureus by a different mechanism to a bacteriocin-like activity.

Topics: Adult; Bacterial Adhesion; Bacteriocins; Colony Count, Microbial; Corynebacterium; Female; Humans; Methicillin Resistance; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

Many hospital-acquired purulent diseases and wound infections are due to multiresistant hospital strains of Staphylococcus aureus. The role of S. aureus nasal carriage in development of wound infections due to autoinfection is confirmed. Not only inpatients but also hospital staff can be highly colonized with coagulase positive staphylococci. The S. aureus persistence in hospital personnel results in distribution of the microorganisms in the environment. Therefore, detection of S. aureus carriers without signs of the infection among the hospital personnel and eradication of the pathogen make it possible to control outbreaks of S. aureus infection in hospitals. Clinical efficacy of nasal ointment of mupirocin in the treatment of S. aureus carriers among the intensive care personnel of the N. N. Blokhin Cancer Research Center was evaluated. S. aureus nasal carriage was diagnosed in 17 (26 per cent) out of 65 persons. All the isolates were susceptible to oxacillin. 5-7 days after discontinuation of the mupirocin nasal ointment use eradication of S. aureus was stated in 100 per cent of the cases. The effect was still observed in 94 per cent of the cases in 1 month, in 76 per cent of the cases in 5-6 months and in 60 per cent of the cases in 8-9 months. It is believed that mupirocin nasal ointment (Bactroban) is convenient to use, low toxic and highly active in the treatment of persons with S. aureus nasal carriage.

Topics: Anti-Bacterial Agents; Carrier State; Colony Count, Microbial; Humans; Medical Staff, Hospital; Microbial Sensitivity Tests; Mupirocin; Nose; Nose Diseases; Ointments; Staphylococcal Infections; Staphylococcus aureus; Time Factors

The action of mupirocin as a nasal ointment (Bactroban) was studied on intranasal carriers of the hospital staphylococcal strains. The study included 37 medical workers from different and mainly problem units of the large general hospital. The tolerability of the ointment was good. After the Bactroban use no complications of the patients were recorded. The efficacy of Bacroban by the microbiological criteria in total amounted to 100 per cent. The eradication of methicillin resistant Staphylococcus aureus (MRSA) was observed in 93 per cent of the cases. A decrease of the level of the nasal passages dissemination by MRSA and methicillin resistant coagulase-negative staphylococci (MRSC) up to such low titers as 100 and 90 per cent was stated. No difference in the action of Bactroban on MRSA, MSSA and MRSC was noted. The bacteriological monitoring for 3 to 4 months revealed a change of the staphylococcal strains in 94 per cent of the cases, recolonization by the same staphylococcal strain in 19 per cent, recolonization by some another staphylococcal strains in 33 per cent and no recolonization in 14 per cent. A stable decrease of staphylococcal strains was possible with simultaneous Bactroban sanitation of all the bacterial carriers of the hospital or its isolated unit.

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Humans; Medical Staff, Hospital; Microbial Sensitivity Tests; Mupirocin; Nose; Nose Diseases; Staphylococcal Infections; Staphylococcus

The combination of a 4% tea tree oil nasal ointment and 5% tea tree oil body wash was compared with a standard 2% mupirocin nasal ointment and triclosan body wash for the eradication of methicillin-resistant Staphylococcus aureus carriage. The tea tree oil combination appeared to perform better than the standard combination, although the difference was not statistically significant due to the small number of patients.

Topics: Administration, Cutaneous; Adult; Aged; Aged, 80 and over; Anti-Infective Agents, Local; Carrier State; Cross Infection; Female; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Pilot Projects; Staphylococcal Infections; Tea Tree Oil

Methicillin-resistant Staphylococcus aureus from nasal discharge was identified in 37 (2.5%) cardiovascular patients operated between 1995 and 1997; 25 male and 12 female, ranging from 1 to 83 years (mean 63); 2 were excluded because of Arbekacin or Isodine-gel treatment. The first 17 were treated with Vancomycin inhalation (V group) and eradication was considered to have been achieved when 3 consecutive negative cultures were obtained; the subsequent 18 were treated with Mupirocin (M group) and eradication was determined by 1 negative culture. In post-eradication electively operated 13 V and 15 M, postoperative MRSA infection was observed in one M (wound infection); the interval from the first nasal culture to the operation was 68 +/- 58 in V and 32 +/- 12 days in M, respectively (p < 0.05). In the remaining 7 who had to undergo emergency surgery while waiting for eradication because of progression of symptoms (2 V) or prior to instituting treatment (2 V, and 3 M), postoperative MRSA infection was observed in 2 M (both pneumonia). No deaths from infection were observed. Though the time required for conversion of the nasal culture was longer in V (13 +/- 20) than in M (7 +/- 1 days) differences were not significant. Mupirocin is easier to use, eradication can be achieved generally within a week.

Topics: Administration, Intranasal; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Cardiac Surgical Procedures; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Staphylococcal Infections

To determine, among patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who were Staphylococcus aureus nasal carriers, if periodic brief "pulses" of nasal mupirocin calcium ointment 2% after completion of a mupirocin eradication protocol would maintain these patients free of carriage.. Noncomparative, nonblinded study with historical controls.. A county medical center.. Patients in a CAPD program during the period April 1996 to May 1998.. All patients in the CAPD program had monthly nasal cultures for S. aureus. After informed consent, S. aureus nasal carriers were administered mupirocin to the nares twice a day for 5 days followed by nasal mupirocin twice monthly. Peritonitis and exit-site infection rates were monitored independently by CAPD nursing staff. Patients were monitored monthly for adverse effects of mupirocin and compliance with the maintenance regimen.. Twenty-four patients in the CAPD program were enrolled in the study and had a median duration of follow-up of 8.5 months. Fifteen (63%) of the 24 patients remained free of nasal carriage on follow-up cultures. Of the 9 patients with positive nasal cultures during the study, 8 had only one positive culture. There was no significant difference in the mean yearly peritonitis rate or S. aureus peritonitis rate (January 1995-May 1998). However, there was a significant decrease in the mean yearly exit-site infection rates both overall (from 8.8 episodes per 100 patients dialyzed per month in 1995 to 4.0 in 1998; P = .008) and due to S. aureus (from 5.6 in 1995 to 0.9 in 1998; P = .03). Adverse effects of nasal mupirocin were mild overall; 1 patient was removed from the study due to an allergic reaction to mupirocin.. Among CAPD patients who were S. aureus nasal carriers, periodic brief treatment with nasal mupirocin after an initial eradication regimen kept them free of carriage, for the most part, with few adverse effects. The pulse mupirocin regimen offers simplicity and possibly better compliance, as well as minimizing exposure to this agent, thereby possibly reducing the risk of resistance. Further studies are warranted to compare this regimen to other commonly used mupirocin maintenance regimens in dialysis patients.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Drug Administration Schedule; Humans; Middle Aged; Mupirocin; Nose; Ointments; Peritoneal Dialysis, Continuous Ambulatory; Staphylococcal Infections

The importance of Staphylococcus aureus as etiological agent for catheter-related infections and peritonitis in peritoneal dialysis patients is well established. To evaluate groups at risk of developing Staphylococcus aureus infections, nasal and exit-site cultures were performed in 76 peritoneal dialysis patients monthly over a period of 3 yr. The risk of Staphylococcus aureus catheter infection was significantly higher in diabetic (group 1) and immunosuppressed (group 2) patients compared with nondiabetic and nonimmunosuppressed (group 3) patients. In diabetic patients, Staphylococcus aureus-positive nasal cultures were more frequent than positive cultures taken from the bland exit-site (73.3% versus 60.0%). On the other hand, both positive and negative exit-site cultures had a better prognostic value for Staphylococcus aureus catheter infection compared with nasal cultures. In immunosuppressed patients, both nasal and exit-site carriages were associated with a very high risk of Staphylococcus aureus catheter infection, but nasal swabs were far more often positive than swabs from the bland exit-site (72.7% versus 25.0%). However, the risk of infection was also high for non-nasal and non-exit-site carriers in this group. In nondiabetic and nonimmunosuppressed patients, the risk of Staphylococcus aureus catheter infection was increased only if two or more positive nasal cultures were detected. It is concluded that in diabetic patients, antibiotic prophylaxis should be performed in all Staphylococcus aureus exit-site carriers. All immunosuppressed patients should be treated prophylactically. In contrast, in nondiabetic and nonimmunosuppressed patients, prophylactic treatment should be considered only in nasal carriers with two or more positive cultures. The overall low peritonitis rate does not influence this prevention strategy.

Topics: Adult; Aged; Analysis of Variance; Catheterization; Diabetes Complications; Female; Humans; Immunocompromised Host; Incidence; Kidney Failure, Chronic; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

We analyzed the effect of perioperative elimination of nasal carriage of Staphylococcus aureus using mupirocin nasal ointment on the reduction of the postoperative wound infection rate in orthopedics. In an unblinded intervention trial, we compared 1,044 patients treated with mupirocin (intervention group) with 1,260 historical controls (control group). From each group a random sample of 50 patients was taken. Risk factors were analyzed in these random samples and we found it unlikely that different distributions of risk factors might have influenced the results. The wound infection rates were 14/1,044 in the intervention group and 34/1,260 in the control group (p = 0.02). The rates of wound infections caused by S. aureus were subsequently 7/1,044 and 14/1,260 (p = 0.3). On checking the data we found that prophylaxis had unintentionally not been given to 172 patients in the intervention group. Correction of the data gave a comparable total infection rate, but a further reduced infection rate by S. aureus. Our findings suggest that prophylactic treatment with mupirocin in orthopedic surgery can reduce the infection rate.

Topics: Administration, Intranasal; Aged; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Female; Humans; Infection Control; Male; Mupirocin; Nose; Ointments; Orthopedic Procedures; Risk Factors; Staphylococcal Infections; Surgical Wound Infection

The objective of this study was to compare prophylaxis for Staphylococcus aureus infections in peritoneal dialysis patients using 600 mg cyclic oral rifampin for 5 days every 3 months versus mupirocin calcium ointment 2% applied daily to the exit site. The study design was a prospective randomized trial, controlling for S aureus nasal carriage. Eighty-two continuous ambulatory and continuous cyclic peritoneal dialysis patients (54% male, 71 % white, 34% insulin-dependent, mean prestudy time on peritoneal dialysis 1.2 years) were randomly assigned to cyclic rifampin (n = 41 patients) or daily exit site mupirocin prophylaxis (n = 41 patients). Mean follow-up was 1 year. S aureus catheter infection rates were 0.13/yr with mupirocin and 0.15/yr with rifampin (P = NS). Both rates were significantly lower than the center's historical rate (the period between 1983 and 1992) of 0.46/yr prior to the study (P < 0.001). S aureus peritonitis rates were 0.04/yr with mupirocin and 0.02/yr with rifampin (P = NS), both significantly lower than the center's historical rate of 0.16/yr (P < 0.02). Catheter loss due to S aureus infections was 0.02/yr with mupirocin and 0/yr with rifampin (P = NS), both significantly lower than the center's historical rate of 0.12/yr (P < 0.001). There were no side effects in patients using mupirocin, but 12% were unable to continue rifampin due to side effects. We conclude that mupirocin ointment at the exit site and cyclic oral rifampin are equally effective in reducing S aureus catheter infections. In addition, rifampin or mupirocin significantly reduced S aureus peritonitis and catheter loss due to S aureus infections. Mupirocin at the exit site provides an excellent alternative prophylaxis for S aureus infections, particularly in patients who cannot tolerate oral rifampin therapy.

Topics: Administration, Cutaneous; Administration, Oral; Adult; Anti-Bacterial Agents; Catheters, Indwelling; Chemoprevention; Diabetes Mellitus, Type 1; Drug Administration Schedule; Equipment Contamination; Equipment Failure; Female; Follow-Up Studies; Humans; Male; Mupirocin; Nose; Ointments; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Prospective Studies; Rifampin; Staphylococcal Infections; Staphylococcus aureus

During two separate periods a total of 654 patients were included in a clinical study relating preoperative bacterial colonization to occurrence of postoperative wound infection in plastic surgery. During the second period one half of the patients were randomized to receive prophylactic azithromycin. Bacteriological samples were collected from the nasal vestibulum during both periods, and additionally from the surgical field during the second period. All patients had preoperative chlorhexidine bathing. The bacteriological findings were categorized as either normal flora or potentially pathogenic bacteria, and as either having no growth. Surgical wounds were divided into four contamination classes. Postoperative follow-up was 30 days, and assessment of wound infection was based on a graded scale. We did not find any statistically significant relation between preoperative bacterial colonization and postoperative wound infection, regardless of place of sample collection, method of bacterial classification, class of contamination or use of prophylactic azithromycin.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Azithromycin; Carrier State; Child; Child, Preschool; Double-Blind Method; Humans; Infant; Infant, Newborn; Middle Aged; Nose; Premedication; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Surgery, Plastic; Surgical Wound Infection

We investigated the long-term effect of a single 5-day application of intranasal mupirocin calcium ointment on Staphylococcus aureus nasal and hand colonization. The subjects were 68 healthy volunteers who were health care workers with stable S aureus nasal carriage and who had participated in a randomized, double-blind placebo-controlled clinical trial of intranasal mupirocin ointment.. A 1-year prospective cohort study of S aureus nasal carriers after treatment with active drug or placebo was performed. Cultures were obtained from all subjects 6 and 12 months after therapy. All subjects returned for the 6-month visit; 63 (93%) were examined at 1 year. The major outcome measure was the relative proportion of any S aureus cultured at either site at 6 and 12 months. The S aureus isolates were typed by restriction endonuclease analysis of plasmid DNA and by antibiotic susceptibility tests; the similarity of nasal and hand isolate "fingerprints" was compared.. At 6 months, nasal carriage was 48% in the treatment group vs 72% in controls (relative risk, 0.68; 95% confidence interval, 0.45 to 1.02; P = .054); at 1 year, nasal carriage was 53% vs 76%, respectively (relative risk, 0.70; 95% confidence interval, 0.48 to 1.02; P = .056). Hand carriage at 6 months was significantly reduced among mupirocin recipients relative to controls (15% and 48%; P = .04, adjusted for the baseline rate of hand carriage). Thirty-six percent of treated subjects were recolonized in the nares with a new strain at 1 year, whereas 34% had reisolation of the original strain after initially negative posttherapy cultures. During the year of follow-up, hand carriage was observed at least once in two thirds of the subjects. Nearly all of the hand isolates (87%) exactly matched the subjects' coincident nasal plasmid fingerprint and antibiogram type.. A single brief treatment course of intranasal mupirocin was effective in reducing nasal S aureus carriage for up to 1 year. When S aureus was recovered after nasal decolonization, the new isolate was as likely to represent colonization with a new strain as reisolation of the original strain. Staphylococcus aureus hand carriage was significantly decreased 6 months after therapy, further implicating the nares as the primary reservoir site for hand carriage.

Topics: Administration, Intranasal; Carrier State; Cohort Studies; Hand; Humans; Mupirocin; Nose; Ointments; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Time Factors; Treatment Outcome

Twenty-six families with recurrent staphylococcal infections were treated with either mupirocin nasal ointment (group M) or chlorhexidine neomycin (Naseptin) cream (group N) to the anterior nares, each combined with chlorhexidine soap for washing and chlorhexidine powder applied to other possible carriage sites. Patients receiving mupirocin following failure with chlorhexidine/neomycin (group M/N) were also treated. Treatment was given for seven days to 99 patients, 32 index (infected) patients and 67 family members. Follow-up swabs were collected by a study nurse 8, 14, 28, and 91 days after starting treatment. The carriage of Staphylococcus aureus in the anterior nares was 67%, in the axillae 22%, in the groin 23%, and perianal 19%. The carriage rates in the index patients was higher than family members, in all sites. The eradication of S. aureus from the nasal carriage site after therapy at 8 days was 95% in group M, 85% in group M/N and 61% in group N. Recolonization during the follow-up period was much less in those treated with mupirocin: 57% of patients in group M and 42% in group M/N were not carriers at 91 days, whereas 89% of patients group N were again colonized. Assessment clinically and in terms of prevention of further infective lesions showed that there was a higher response to mupirocin than to chlorhexidine/neomycin. Mupirocin nasal is a successful therapy for removing nasal carriage of S. aureus and has a prolonged effect on recolonization.

Topics: Anti-Infective Agents, Local; Carrier State; Chlorhexidine; Drug Combinations; Family Health; Humans; Mupirocin; Neomycin; Nose; Ointments; Recurrence; Staphylococcal Infections

To assess the impact of the use of mupirocin ointment on colonization, transmission, and infection with methicillin-resistant Staphylococcus aureus (MRSA) in a long-term-care facility.. All 321 residents of a Veterans Affairs long-term-care facility from June 1990 through June 1991 were studied for MRSA colonization and infection. MRSA-colonized patients received mupirocin ointment to nares in the first 7 months and to nares and wounds in the second 5 months. The effect of mupirocin use on MRSA colonization and infection was monitored. All S. aureus strains isolated were tested for the development of resistance to mupirocin.. A total of 65 patients colonized with MRSA received mupirocin ointment. Mupirocin rapidly eliminated MRSA at the sites treated in most patients by the end of 1 week. Weekly maintenance mupirocin was not adequate to prevent recurrences--40% of patients had recurrence of MRSA. Overall, MRSA colonization in the facility, which was 22.7% +/- 1% prior to the use of mupirocin, did not change when mupirocin was used in nares only (22.2% +/- 2.1%), but did decrease to 11.5% +/- 1.8% when mupirocin was used in nares and wounds. Although colonization decreased, roommate-to-roommate transmission and MRSA infection rates, low to begin with, did not change when mupirocin was used. Mupirocin-resistant MRSA strains were isolated in 10.8% of patients.. Mupirocin ointment is effective at decreasing colonization with MRSA. However, constant surveillance was required to identify patients colonized at admission or experiencing recurrence of MRSA during maintenance treatment. Long-term use of mupirocin selected for mupirocin-resistant MRSA strains. Mupirocin should be saved for use in outbreak situations, and not used over the long term in facilities with endemic MRSA colonization.

Topics: Aged; Carrier State; Cross Infection; Female; Humans; Incidence; Infection Control; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Prevalence; Recurrence; Staphylococcal Infections; Staphylococcus aureus; Wound Infection

Thirty patients commencing isotretinoin for acne were entered into a double-blind, randomized, placebo-controlled trial to investigate the effect of pulsed intra-nasal mupirocin ointment on Staphylococcus aureus colonization and isotretinoin-related side-effects. In both mupirocin and placebo groups there was an increase in isolation of S. aureus throughout the period of treatment with isotretinoin from the anterior nares, facial skin and lips. However, these increases were significantly less in the mupirocin-treated group. A high proportion of all patients suffered inflammatory side-effects of isotretinoin such as cheilitis and nasal vestibulitis, with their maximum severities being recorded 2 months after starting isotretinoin. In spite of the smaller increase in S. aureus colonization in the mupirocin-treated group no difference was demonstrated in either the incidence of specific S. aureus infections (e.g. furunculosis) or the prevalence of isotretinoin-related inflammatory side-effects. Furthermore, no relationship between the presence of S. aureus and the severity of inflammatory side-effects was shown. Streptococcus species were isolated on four separate occasions from four different patients during the study but their pathogenicity was unclear. These findings suggest that although pulsed intra-nasal mupirocin produces a significant reduction in isotretinoin-related staphylococcal colonization, its routine use cannot be justified on the basis of clinical benefit.

Topics: Acne Vulgaris; Administration, Intranasal; Adolescent; Adult; Double-Blind Method; Drug Administration Schedule; Female; Humans; Isotretinoin; Male; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

The effectiveness and safety of mupirocin calcium ointment applied to the anterior part of the nares for 5 days in the eradication of nasal carriage of Staphylococcus aureus was investigated in a placebo-controlled, double-blind study. Subjects were healthy medical center staff who had two positive cultures of the anterior nares for S aureus. Antimicrobial susceptibility, phage typing, and restriction endonuclease analysis of plasmid DNA were used to monitor the identity of relapsing and persisting strains. Mupirocin eliminated 74% of S aureus at early follow-up and 91% of original strains. At 4 weeks, 78% of the original strains were eradicated, whereas all of the placebo group remained colonized. Recolonization with mupirocin-resistant strains occurred in six patients, but these were of different phage and plasmid types from the original isolates. None of the subjects had serious adverse effects. Applied intranasally for 5 days, a calcium preparation of mupirocin in a paraffin base is effective in eliminating S aureus nasal carriage and is well tolerated.

Topics: Adult; Carrier State; Double-Blind Method; Drug Resistance, Microbial; Female; Humans; Male; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

124 stable CAPD patients from 8 Australian and 3 New Zealand centers were randomly assigned in a blinded fashion to one of two groups to study the effect of vaccination using commercial preparations consisting of a combined staphylococcus toxoid and whole killed staphylococci (SB) or normal saline solution (SS) on the incidence of peritonitis and exit site infection and S. aureus nasal carriage over a 12-month prospective period. In addition, levels of IgG, IgA, IgM, C3 and C4 were monitored during the trial period in serum and dialysate; serum levels of anti-alpha hemolysin and dialysate levels of fibronectin and specific antistaphylococcal antibodies were also measured. Over the period, treatment with SB or SS did not affect the incidence of peritonitis, catheter-related infection or S. aureus nasal carriage. However, vaccination with SB elicited a significant increase in the level of serum anti-alpha hemolysin throughout the 12 month duration of the study, although the level of increase was unrelated to the subsequent rate of peritonitis. Vaccination with SB but not SS elicited a significant increase in the dialysate level of specific antibodies against S. aureus. Serum levels of IgG, IgA, IgM, complement C3 and C4 were within the normal range in the CAPD patients studied and remained unaffected by vaccination with SB. In addition, dialysate levels of IgG, IgA, IgM, complement C3 and C4 were 50-100 times lower than corresponding serum levels and remained unaffected by vaccination. In summary, immunisation with an anti-staphylococcal agent was not successful in reducing peritonitis or exit site infection in CAPD patients.

Topics: Catheters, Indwelling; Double-Blind Method; Female; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcal Vaccines; Staphylococcus aureus; Vaccination

To determine the safety and efficacy of mupirocin calcium ointment in the elimination of Staphylococcus aureus nasal and hand carriage in healthy persons.. A double-blind, placebo-controlled, randomized trial.. Clinical research unit of a tertiary medical center.. Health care workers with stable S. aureus nasal carriage.. Subjects (n = 68) were randomly assigned to receive either mupirocin or placebo intranasally twice daily for 5 days.. Cultures of the hands and nares were obtained at baseline and 72 hours after therapy. The nares were also cultured 1, 2, 4, and 12 weeks after therapy. Antimicrobial susceptibility testing and restriction endonuclease analysis of plasmid DNA were used to confirm strain identity. There were no serious side effects. Mupirocin decreased the frequency of S. aureus nasal carriage at each time interval: At 3 months, 71% of subjects receiving mupirocin remained free of nasal S. aureus compared with 18% of controls. This difference (53%; 95% CI; 26% to 80%) was significant (P less than 0.0001). Additionally, analysis of plasmid patterns showed that 79% of subjects in the mupirocin group were free of the initial colonizing strain at 3 months. The proportion of hand cultures positive for S. aureus in the mupirocin group after therapy was lower than in the placebo group (2.9% compared with 57.6%). This difference (53%; 95 CI, 30% to 80%) was significant, after adjustment for the frequency of hand carriage at baseline (P less than 0.0001).. When applied intranasally for 5 days, mupirocin calcium ointment is safe and effective in eliminating S. aureus nasal carriage in healthy persons for up to 3 months and appears to have a corresponding effect on hand carriage at 72 hours after therapy.

Topics: Administration, Intranasal; Adult; Anti-Bacterial Agents; Carrier State; Double-Blind Method; Fatty Acids; Female; Hand; Health Workforce; Humans; Male; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus

Mupirocin was used in haemodialysis patients in an attempt to eradicate nasal carriage of Staphylococcus aureus and to prevent infection caused by this microorganism. The effectiveness of calcium mupirocin as a 2% nasal ointment OB2 (16 patients for 104 patient-months) was compared to that of placebo (18 patients for 147 patient-months) in a double-blind study. Mupirocin or placebo were applied in both anterior nares thrice daily for 2 weeks and subsequently three times weekly for a total of 9 months. During therapy, S. aureus was recovered from only 6% of the nasal cultures in the mupirocin group compared to 58% in the placebo group (P less than or equal to 0.01). Only one S. aureus infection was documented in the mupirocin group compared to six in the placebo group (P less than or equal to 0.05). The S. aureus strain causing the single infection in the mupirocin group was of a different phage type to that of the original nasal strain. In contrast, at least four of the six strains causing infection in the placebo group were of similar phage type to the original nasal strain. All S. aureus isolates remained mupirocin sensitive (MIC less than or equal to 1 mg/l). In conclusion, mupirocin nasal ointment was effective in eradicating nasal carriage of S. aureus and in preventing S. aureus infections in patients on haemodialysis.

Topics: Administration, Intranasal; Aged; Anti-Bacterial Agents; Carrier State; Clinical Trials as Topic; Double-Blind Method; Fatty Acids; Female; Humans; Male; Middle Aged; Mupirocin; Nose; Ointments; Random Allocation; Renal Dialysis; Staphylococcal Infections

Mupirocin eliminates nasal carriage of Staphylococcus aureus among medical and surgical personnel for periods varying from several weeks up to one year. In persons recolonized after therapy densities of S. aureus populations in nares were much lower than in the same persons before therapy.

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Double-Blind Method; Fatty Acids; Humans; Mupirocin; Nose; Personnel, Hospital; Poland; Staphylococcal Infections

The changes in coagulase-negative staphylococcal flora induced by cefamandole prophylaxis were compared with those induced by pefloxacin prophylaxis among patients undergoing heart valve surgery. Twenty-five patients (15 receiving cefamandole prophylaxis and 10 receiving pefloxacin prophylaxis) were included in the study. In the pefloxacin group, colonization rates in anterior nares and in chest skin or wound that were 60% and 50% respectively before surgery, became 50% and 20% respectively after surgery. In the cefamandole group, colonization rates in anterior nares and chest skin or wound were 53.3% and 60% respectively before surgery and became 53.3% and 40% respectively after surgery. Cefamandole did not appear to induce the emergence of oxacillin or pefloxacin resistant coagulase-negative staphylococcal colonization in any cultured site. On the other hand pefloxacin appeared somewhat more efficacious than cefamandole in eradicating staphylococcal flora of anterior nares and chest skin or wound. Pefloxacin and oxacillin resistant strains were found in the perianal area in 0% of patients before pefloxacin prophylaxis and in 70% of patients after pefloxacin prophylaxis. However, further studies are necessary to confirm the emergence of antibiotic resistant coagulase-negative staphylococci in the intestinal microflora after quinolone administration. The clinical implications of such apparently disturbing phenomenon remain to be evaluated.

Topics: Cefamandole; Coagulase; Heart Valve Prosthesis; Humans; Nose; Pefloxacin; Postoperative Care; Premedication; Randomized Controlled Trials as Topic; Skin; Staphylococcal Infections; Staphylococcus

We conducted a five-year prospective controlled study of prophylaxis of Staphylococcus aureus nasal carriage and infection among patients in a hemodialysis unit. Carriers tended to have chronic colonization with a single phage type. S. aureus infections occurred significantly more frequently in carriers than in noncarriers and, in 93 percent of the infected carriers, were caused by the same phage type as that carried in the nares. Neither intravenous vancomycin nor topical bacitracin was found to be efficacious in eradicating nasal carriage. However, oral rifampin given for five days decreased S. aureus carriage over a one-month follow-up period, but within three months colonization of the nares recurred in most carriers, often with an S. aureus of the original phage type. Carriers were then randomly assigned to receive either rifampin or no prophylaxis. Rifampin was readministered at three-month intervals if culture of the anterior nares yielded S. aureus. Infections with S. aureus occurred significantly more frequently in carriers given no prophylaxis than in those given a full course of rifampin. S. aureus resistant to rifampin was isolated from the anterior nares of four patients, but these isolates were not implicated in any infections. The incidence of infection at the dialysis access site, skin, and soft tissue of patients on hemodialysis can be decreased by interventions directed at nasal carriage of S. aureus.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Bacitracin; Bacteriophage Typing; Carrier State; Clinical Trials as Topic; Double-Blind Method; Drug Administration Schedule; Drug Evaluation, Preclinical; Humans; Injections, Intravenous; Nose; Prospective Studies; Random Allocation; Renal Dialysis; Rifampin; Staphylococcal Infections; Staphylococcus aureus; Vancomycin

Topics: Baths; Clinical Trials as Topic; Female; Humans; Infant, Newborn; Male; Nose; Random Allocation; Staphylococcal Infections; Staphylococcus aureus; Umbilical Cord

A wide variety of bacterial species, many usually regarded as of low pathogenicity, were isolated from septic joints after operation for total hip or knee joint replacement in a multi-centre trial of ultraclean air in operating rooms. The prophylactic antibiotics generally used appeared to reduce considerably the rates of infection with most species but to be ineffective against 'gut' organisms. For about half the septic infections involving Staphylococcus aureus nasal swabs had been obtained from the patient and operating staff at the time of operation for insertion of the prosthesis. Strains of Staph, aureus isolated from these and from the infected joints were phage typed and tested for antibiotic sensitivity. A probable source among the carriers was found for seven out of the 14 infections and a possible source for another five. Very small numbers of Staph. aureus were needed to initiate infection.

Topics: Air Microbiology; Bacteria; Carrier State; Hip Joint; Hip Prosthesis; Humans; Joint Diseases; Joint Prosthesis; Knee Joint; Knee Prosthesis; Nose; Perineum; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Serial quantitative nasal cultures were performed on 87 healthy nasal carriers of Staphylococcus aureus, who were randomly assigned to 7 days of oral therapy with erythromycin, rosamicin (an investigational macrolide antibiotic), or placebo. Staphylococcal carrier rates decreased during therapy with both antibiotics; however, erythromycin was significantly more effective in lowering carrier rates than was rosamicin. The anti-staphylococcal effects of both antibiotics were similar when the mean numbers of S. aureus isolated from positive cultures during therapy were compared. Side effects to each regimen were minimal.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Carrier State; Erythromycin; Female; Humans; Leucomycins; Male; Nose; Placebos; Staphylococcal Infections

Healthy nasal carriers of Staphylococcus aureus were randomly assigned to one of three treatment regimens: josamycin (1.5 g/day), erythromycin stearate (1.0 g/day), or placebo, each administered orally for 7 days. Quantitative nasal cultures were obtained from each subject at intervals before, during, and after treatment. All 25 placebo-treated subjects had positive nasal cultures for S. aureus at all culture intervals. Both josamycin and erythromycin were equally effective in reducing the carrier rates and in decreasing the total numbers of S. aureus isolated from subjects with positive cultures during treatment. No increase in in vitro antibiotic resistance was detected in isolates obtained after therapy. Both antibiotics were well tolerated, and toxicity was not encountered with either drug.

Topics: Anti-Bacterial Agents; Carrier State; Clinical Trials as Topic; Drug Resistance, Microbial; Erythromycin; Humans; Leucomycins; Nose; Placebos; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Topics: Administration, Oral; Adult; Clinical Trials as Topic; Cyclohexylamines; Female; Humans; In Vitro Techniques; Male; Microbial Sensitivity Tests; Nose; Penicillanic Acid; Penicillins; Placebos; Proteus Infections; Proteus mirabilis; Sinusitis; Staphylococcal Infections; Staphylococcus; Time Factors

The effectiveness of two oral antibiotics, cloxacillin and sodium fusidate, has been evaluated in the treatment of shunt infections among 37 patients allocated at random to two treatment groups. Both proved to be safe bactericidal agents giving adequate serum M.I.C. when taken by mouth. Treatment should always be started on the basis of the clinical presentation without waiting for the bacteriologist's report. The commonest infecting organism is Staphylococcus aureus. Nine shunts were lost in this study, eight through Staphylococcus aureus infection. The nasal carrier state is of considerable importance in perpetuating these shunt infections.

Topics: Arteriovenous Shunt, Surgical; Carrier State; Cloxacillin; Fusidic Acid; Humans; Nose; Staphylococcal Infections; Surgical Wound Infection

The efficacy of lysostaphin nasal spray and Neosporin ointment (Burroughs Wellcome & Co.) in altering nasal carriage of Staphylococcus aureus was studied with persistent carriers in an institution for mentally retarded children and adults. Treatment for 5 days with either agent significantly reduced carriage rates. This effect persisted through the 5th day after therapy with lysostaphin but not with Neosporin. By the 11th day after therapy, carriage rates in the treatment and control groups were not significantly different. Except for a single immediate wheal and flair skin test reaction, no other evidence of adverse reactions to topical lysostaphin was detected. No consistent changes in hemagglutination-inhibition titers to lysostaphin were observed after therapy. Lysostaphin appears to be slightly more effective than conventional topical antimicrobial therapy in reducing nasal carriage of staphylococci in this rigorously defined population of persistent carriers.

Topics: Adult; Aerosols; Anti-Bacterial Agents; Bacitracin; Bacteriophage Typing; Carrier State; Child; Clinical Trials as Topic; Diagnosis, Differential; Evaluation Studies as Topic; Hemagglutination Inhibition Tests; Humans; Intellectual Disability; Lysostaphin; Neomycin; Nose; Ointments; Placebos; Polymyxins; Skin Tests; Staphylococcal Infections; Staphylococcus; Time Factors

The use of the quantitative nasal culture was investigated as a means of evaluation of new antimicrobial drugs in man. Cyclacillin was somewhat more active in vitro than penicillin G against penicillin G-resistant organisms. Cyclacillin was highly effective in suppressing staphylococci susceptible to penicillin G in nasal carriers but did not suppress staphylococci resistant to penicillin G. Although in previous studies by others cyclacillin was effective in treating mice infected with penicillin G-resistant staphylococci, in the present studies cyclacillin was not effective in suppressing nasal penicillin G-resistant staphylococci in man at doses which markedly suppressed penicillin G-sensitive organisms.

Topics: Administration, Oral; Carrier State; Clinical Trials as Topic; Coagulase; Humans; Microbial Sensitivity Tests; Nose; Penicillin G; Penicillin Resistance; Penicillins; Placebos; Staphylococcal Infections; Staphylococcus

Topics: Anti-Bacterial Agents; Carrier State; Clinical Trials as Topic; Coagulase; Diphtheria; Gentamicins; Humans; Lysostaphin; Nose; Placebos; Staphylococcal Infections; Staphylococcus

Topics: Adolescent; Carrier State; Child, Institutionalized; Disease Outbreaks; Drug Resistance, Microbial; Humans; Impetigo; Intellectual Disability; Male; Nose; Staphylococcal Infections; Staphylococcus; Tetracycline; Virulence

To improve adherence with pre-surgical screening for Staphylococcus aureus nasal carriage and decolonization, we need more information about patients' experiences with these protocols.. We surveyed patients undergoing orthopedic, neurosurgical, or cardiac operations at Johns Hopkins Hospitals (JHH), the University of Iowa Hospitals and Clinics (UIHC) at MercyOne Northeast Iowa Neurosurgery (MONIN) to assess patients' experiences with decolonization protocols.. Five hundred thirty-four patients responded. Respondents at JHH were significantly more likely than those at the UIHC to report using mupirocin and were significantly more likely than those at the UIHC and MONIN to feel they received adequate information about surgical site infection (SSI) prevention and decolonization. Respondents at JHH were the least likely to not worry about SSI and they were more willing to do anything they could to prevent SSI. Few patients reported barriers to adherence and side effects of mupirocin or chlorhexidine.. Respondents did not report either major side effects or barriers to adherence. Patients varied in their level of concern about SSI, their willingness to invest effort in preventing SSI, and their assessments of preoperative information. To improve patients' adherence, clinicians and hospitals should assess their patients' needs and desires and tailor their preoperative processes, education, and prophylaxis accordingly.

Topics: Anti-Bacterial Agents; Carrier State; Chlorhexidine; Humans; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

To compare the culture sensitivities of MRSA detection, we collected 988 paired umbilical and nasal cultures from screened neonates. MRSA positivity rates were 79.1% from umbilicus and 41.9% from nares (

Topics: Humans; Infant, Newborn; Intensive Care Units; Intensive Care Units, Neonatal; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Umbilicus

Academic hospital nurses were surveyed to assess adherence barriers to a universal povidone-iodine nasal decolonization protocol to prevent

Topics: Anti-Bacterial Agents; Carrier State; Humans; Inpatients; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Povidone-Iodine; Staphylococcal Infections; Staphylococcus aureus

The utility of methicillin-resistant Staphylococcus aureus (MRSA) nasal surveillance swabs has not been well-described in children. This retrospective, cohort study yielded a negative predictive value of 99.4% for an initial negative MRSA nasal surveillance swab in 165 hospitalized children with a suspected infection and clinical cultures obtained from a likely site of infection.

Topics: Child; Cohort Studies; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Retrospective Studies; Staphylococcal Infections

Bacterial nasal colonization is common in many mammals and Staphylococcus represents the main pathogen isolated. Staphylococcus nasal carriage in humans constitutes a risk factor for Staphylococcus infections pointing out the need for animal experimentation for nasal colonization studies, especially for vaccine development. A limitation in addressing this hypothesis has been a lack of appropriate animal model. Murine models do not mimic human nasal colonization studies. Non-human primates (NHP) remain the best classical models for nasal colonization studies. In this study, we analyzed nasal colonization between two species of Old World monkeys (cynomolgus and rhesus) and a New World monkey (squirrel monkey) from breeding colony at Fiocruz (Brazil). Sixty male and female NHP with the average age of 1-21 years old, comprising twenty animals of each species, were analyzed. Nine different Staphylococcus species (S. aureus, S. cohnii, S. saprophyticus, S. haemolyticus, S. xylosus, S. warneri, S. nepalensis, S. simiae, and S. kloosi) were identified by MALDI-TOF and 16S rRNA gene sequence analyses. Antibiotic resistance was not detected among the isolated bacterial population. S. aureus was the main isolate (19 strains), present in all species, predominant in cynomolgus monkeys (9/20) and squirrel monkeys (7/20). spa typing was used to examine the clonal structure and genetic profile of Staphylococcus aureus isolates. Eight (8) spa types were identified among the S. aureus strains. A major cluster was identified, corresponding to a new spa type t20455, and no spa types found in this study were seen before in Brazil.

Topics: Animals; Carrier State; Female; Humans; Male; Mammals; Methicillin-Resistant Staphylococcus aureus; Mice; Nose; Primates; RNA, Ribosomal, 16S; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus

Consensus guidelines for antibiotic prophylaxis in endoscopic endonasal surgery (EES) have not been developed. The study objective was to define the microbiologic and clinical characteristics of post-EES central nervous system (CNS) infections.. This was a single-center retrospective study of patients >18 years of age who underwent EES between January 2010 and July 2021 at a high-volume skull base center. Patients with confirmed CNS infection within 30 days of EES were included. During the study period, the standard prophylaxis regimen was ceftriaxone 2 g every 12 hours for 48 hours. For patients with a documented penicillin allergy, vancomycin plus aztreonam was recommended.. In total, 2440 EES procedures were performed on 2005 patients; the CNS infection rate was 1.8% (37/2005). CNS infections were more common among patients with a history of previous EES (6.5%; 20/307) compared with those who did not (1%; 17/1698; P < 0.001). The median time from EES to CNS infection was 12 (6-19) days. Thirty-two percent (12/37) of CNS infections were polymicrobic, which was more common among patients without previous EES (52.9%; 9/17) compared with those with previous EES (15%; 3/20; P = 0.03). Across all cases, Staphylococcus aureus (n = 10) and Pseudomonas aeruginosa (n = 8) were commonly isolated pathogens. Among those with confirmed methicillin-resistant Staphylococcus aureus (MRSA) nares colonization before EES, 75% (3/4) developed MRSA CNS infections compared with 6.1% (2/33) of noncolonized patients (P = 0.005).. CNS infection after EES is rare and causative pathogens vary. Further studies are needed to identify the impact of MRSA nares screening on antimicrobial prophylaxis before EES.

Topics: Anti-Bacterial Agents; Central Nervous System Infections; Endoscopy; Humans; Methicillin-Resistant Staphylococcus aureus; Nervous System Malformations; Nose; Retrospective Studies; Staphylococcal Infections

This study aimed to investigate the prevalence and molecular characteristics of community methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among students at Kabul University.. Nasal swabs were collected from anterior nares of 150 healthy non-medical students at Kabul University. Antimicrobial susceptibility testing was performed on all S. aureus isolates, and all detected MRSA isolates were then confirmed by mecA/mecC polymerase chain reaction and characterized using DNA microarray.. A total of 50 S. aureus strains were isolated from the anterior nares of the 150 participants. The prevalence of S. aureus and MRSA nasal carriage among Kabul students was 33.3% and 12.7%, respectively. Seven (36.8%) MRSA isolates and 8 (25.8%) methicillin-susceptible S. aureus (MSSA) isolates were multidrug-resistant (i.e. resistant to at least three different antimicrobials tested). All MRSA isolates (n = 19) were susceptible to linezolid, rifampicin, and fusidic acid. Seven MRSA clones, belonging to four clonal complexes (CCs), were identified. The most commonly identified clone was CC22-MRSA-IV TSST-1-positive, which accounted for 63.2% (12/19) of MRSA isolates. SCCmec typing showed that most MRSA strains harboured SCCmec type IV (94.7%). Thirteen (68.4%) MRSA isolates carried the TSST-1 and 5 (26.3%) PVL genes.. Our findings revealed the relatively high prevalence of MRSA nasal carriers in the community in Kabul, with the predominance of the CC22-MRSA-IV TSST-1-positive clone and frequent multidrug resistance among these isolates.

Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Carrier State; Humans; Nasal Cavity; Nose; Staphylococcal Infections; Surgical Wound Infection

Methicillin-resistant Staphylococcus aureus (MRSA) can cause serious infections and empiric treatment regimens in children frequently include an anti-MRSA antibiotic. Studies in adults have demonstrated a high negative predictive value (NPV) of MRSA nasal swabs (MNS) in a variety of infectious syndromes. Negative MNS have been utilized as a tool to guide de-escalation of anti-MRSA antibiotics in adults, especially in those with lower respiratory tract infections, but data in children is minimal. The primary objective of this study was to determine the NPV and positive predictive value (PPV) of MNS in children hospitalized for treatment of an infection.. This was a single-site, retrospective cohort study of pediatric patients admitted with a suspected infectious diagnosis who had an MNS performed during their hospitalization between June 1, 2018 and November 25, 2022.. This study identified 172 patients who met the inclusion criteria. Eleven (6.4%) nasal swabs were positive for MRSA and 10 (5.8%) microbiological cultures from suspected sources of infection were identified to be positive for MRSA. The MNS was found to have a sensitivity of 20%, specificity of 94%, PPV of 18% and NPV of 95% for all sites of infection.. MNS has a high NPV and low PPV in children. MNS can be utilized as an antimicrobial stewardship tool to guide the safe de-escalation of anti-MRSA antibiotics in children.

Topics: Adult; Anti-Bacterial Agents; Antimicrobial Stewardship; Child; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Retrospective Studies; Staphylococcal Infections

Topics: Anti-Bacterial Agents; Chlorhexidine; Humans; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Staphylococcal Infections

Diabetic foot infections are a common complication of diabetes.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Foot; Humans; Methicillin-Resistant Staphylococcus aureus; Mice; Nasal Cavity; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Antimicrobial Stewardship; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Povidone-Iodine; Staphylococcal Infections

Topics: Animals; Humans; Livestock; Methicillin-Resistant Staphylococcus aureus; Nose; Occupational Exposure; Staphylococcal Infections; Staphylococcus aureus

Healthcare-associated infections pose a potentially fatal threat to patients worldwide and Staphylococcus aureus is one of the most common causes of healthcare-associated infections. S. aureus is a common commensal pathogen and a frequent cause of bacteremia, with studies demonstrating that nasal and blood isolates from single patients match more than 80% of the time. Here we report on a contemporary collection of colonizing isolates from those with methicillin-resistant S. aureus (MRSA) bloodstream infections to evaluate the diversity within hosts, and detail the clinical features associated with concomitant nasal colonization.. Swabs of the bilateral anterior nares were obtained from patients diagnosed with MRSA bacteremia. A single colony culture from the blood and an average of 6 colonies from the nares were evaluated for MRSA growth. For the nares cultures, we typed multiple isolates for staphylococcal protein A (spa) and derived the clonal complexes. Demographic and clinical data were obtained retrospectively from the electronic medical record system and analysed using univariate and multivariable regression models.. Over an 11-month period, 68 patients were diagnosed with MRSA bloodstream infection, 53 were swabbed, and 37 (70%) were colonized with MRSA in the anterior nares. We performed molecular typing on 213 nasal colonies. Spa types and clonal complexes found in the blood were also detected in the nares in 95% of the cases. We also found that 11% of patients carried more than one clone of MRSA in the nares. Male sex and history of prior hospitalization within the past 90 days increased odds for MRSA colonization.. The molecular epidemiological landscape of colonization in the setting of invasive disease is diverse and defining the interplay between colonization and invasive disease is critical to combating invasive MRSA disease.

Topics: Bacteremia; Carrier State; Cross Infection; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Retrospective Studies; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Humans; Mice; Nasal Cavity; Nose; Staphylococcal Infections; Staphylococcus aureus; Virulence; Virulence Factors

Male sex is associated with higher risk of both colonisation and infection with Staphylococcus aureus (S. aureus). However, the role of sex-steroids in colonisation among men is largely unknown. Thus, the aim of this study was to investigate possible associations between circulating sex-steroids and nasal carriage of S. aureus in a general male population. The population-based Tromsø6 study (2007-2008) included 752 males aged 31-87 years with serum sex-steroids measured by liquid chromatography tandem mass spectrometry and two nasal swab samples for the assessment of S. aureus carriage. Multivariable logistic regression models were used to study the association between sex-steroid concentrations and S. aureus persistent nasal carriage (two positive swabs vs. others), while adjusting for potential confounding factors.S. aureus persistent nasal carriage prevalence was 32%. Among men aged 55 years and above (median age 65 years), there was an inverse dose-response relationship between serum concentration of testosterone and persistent nasal carriage, and carriers had significantly lower mean levels of testosterone (P = 0.028, OR = 0.94 per nmol/l change in testosterone; 95% CI = 0.90-0.98). This association was attenuated when adjusting for body mass index and age (OR = 0.96 per nmol/l change in testosterone; 95% CI = 0.91-1.01). There was no association in the total population. This large population-based study suggests that testosterone levels may be inversely related to S. aureus persistent nasal carriage in older men. Future studies addressing biological mechanisms underlying the male predisposition to S. aureus colonisation and infection may foster preventive interventions that take sex-differences into account.

Topics: Aged; Carrier State; Female; Humans; Male; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Testosterone

Topics: Animals; Disease Models, Animal; Humans; Mice; Nasopharynx; Nose; Staphylococcal Infections; Staphylococcus aureus

The human nose harbors various microbes that decisively influence the wellbeing and health of their host. Among the most threatening pathogens in this habitat is

Topics: Bacteria; Humans; Methicillin-Resistant Staphylococcus aureus; Microbiota; Nose; Staphylococcal Infections; Staphylococcus aureus

Hand eczema (HE) is frequently associated with Staphylococcus aureus; however, its role in the pathogenesis of HE is poorly understood.. To investigate the temporal variation in S aureus subtypes, ie, clonal complex (CC) types, on the hands and relate it to S aureus colonization in the nose and severity in a cohort of HE patients.. S aureus from the hands and nose of 50 adult HE patients and 50 controls was prospectively identified at 5 visits over 3 weeks.. S aureus was identified on the hands of 23 (46%) patients at 2 or more visits and on the hands of 1 control once. Of the HE patients with S aureus colonization, 78% had the same S aureus CC type over time. Twenty-one patients had the same S aureus CC type on the hands and in the nose. Persistent colonization was strongly related to an increased disease severity.. A relatively small S aureus culture-positive population.. The temporal stability of S aureus CC type and high occurrence of the identical subtypes on the hands and in the nose imply that S aureus colonization in patients with HE is of a more permanent nature. Taken together with the finding that persistent colonization and HE severity are clearly related, our results indicate that S aureus may contribute to the perpetuating course of HE.

Topics: Adult; Dermatitis, Atopic; Eczema; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

To characterize the Staphylococcus aureus strains colonizing healthy Spanish children.. Between March and July 2018, 1876 Spanish children younger than 14 years attending primary healthcare centers were recruited from rural and urban areas. Staphylococcus aureus colonization of the anterior nostrils was analyzed. MecA and mecC genes, antibiotic susceptibility, and genotyping according to the spa were determined in all strains, and the following toxins were examined: Panton-Valentine leucocidin (pvl), toxic shock syndrome toxin (tst), and exfoliative toxins (eta, etb, etd). Multilocus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing were performed on methicillin-resistant Staphylococcus aureus (MRSA) strains, as well as pulsed-field gel electrophoresis (PFGE).. 619 strains were isolated in 1876 children (33%), and 92% of them were sent for characterization to the Spanish National Centre of Microbiology (n = 572). Twenty (3.5%) of these strains were mecA-positive. Several spa types were detected among MRSA, being t002 the most frequently observed (30%), associating with SCCmec IVc. Among MSSA, 33% were positive for tst, while only 0.73% were positive for pvl. The 20 MRSA strains were negative for pvl, and 6 (30%) harbored the tst gene.. methicillin-resistant Staphylococcus aureus nasal colonization in Spanish children is rare, with t002 being the most observed spa type, associated with SCCmec IVc. None of the MRSA strains produced pvl, but up to 30% of S. aureus strains were positive for tst.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacterial Toxins; Child; Child, Preschool; DNA, Bacterial; Drug Resistance, Bacterial; Exfoliatins; Exotoxins; Female; Genotyping Techniques; Humans; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Penicillin-Binding Proteins; Spain; Staphylococcal Infections; Staphylococcal Protein A

The microorganisms at the workplace contribute towards a large portion of the biodiversity a person encounters in his or her life. Health care professionals are often at risk due to their frontline nature of work. Competition and cooperation between nasal bacterial communities of individuals working in a health care setting have been shown to mediate pathogenic microbes. Therefore, we investigated the nasal bacterial community of 47 healthy individuals working in a clinical research laboratory in Kuwait. The taxonomic profiling and core microbiome analysis identified three pre-dominant genera as Corynebacterium (15.0%), Staphylococcus (10.3%) and, Moraxella (10.0%). All the bacterial genera exhibited seasonal variations in summer, winter, autumn and spring. SparCC correlation network analysis revealed positive and negative correlations among the classified genera. A rich set of 16 genera (q < 0.05) were significantly differentially abundant (LEfSe) across the four seasons. The highest species counts, richness and evenness (P < 0.005) were recorded in autumn. Community structure profiling indicated that the entire bacterial population followed a seasonal distribution (R2-0.371; P < 0.001). Other demographic factors such as age, gender and, ethnicity contributed minimally towards community clustering in a closed indoor laboratory setting. Intra-personal diversity also witnessed rich species variety (maximum 6.8 folds). Seasonal changes in the indoor working place in conjunction with the outdoor atmosphere seems to be important for the variations in the nasal bacterial communities of professionals working in a health care setting.

Topics: Adult; Bacteria; Bacterial Infections; Clinical Laboratory Services; Corynebacterium; Corynebacterium Infections; Female; Health Personnel; Humans; Kuwait; Male; Microbiota; Middle Aged; Moraxella; Moraxellaceae Infections; Nose; Seasons; Staphylococcal Infections; Staphylococcus; Young Adult

Endoscopic endonasal skull base surgery (EESBS) is a clean-contaminated procedure. Guidelines regarding the antibiotic prophylaxis in EESBS have not been developed yet, and today, there are no universally accepted protocols. In this article, we investigated the efficacy of our new ultra-short antibiotic prophylaxis protocol for EESBS guided by the cultural results of preoperative microbiological nasal swabs.. We defined as "nasal swab-related antibiotic protocol" the administration of a first-generation cephalosporin (cefazolin 2 g) in patients whose nasal swabs revealed the presence of normal nasal flora or methicillin-sensitive Staphylococcus aureus (MSSA), and the administration of vancomycin 1 g intravenously in patients whose nasal swabs revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA) or with reported cephalosporin/penicillin allergy. This case-control study included 120 patients who underwent EESBS. The case group included 60 cases who received the "nasal swab-related antibiotic protocol," while the control group included 60 cases who received the "standard hospital antibiotic protocol" used in neurosurgery (cefazolin 2 g plus metronidazole 500 mg at induction, and 2 g of cefazolin repeated after 180 min).. The preoperative microbiological nasal swabs showed normal nasal flora in 42 patients (70%), MSSA in 17 patients (28.3%), and MRSA in 1 patient (1.6%). During the study period, no cases of meningitis or sinusitis occurred in the case group ("nasal swab-related antibiotic protocol"), while two infections (3.3%, 1 sinusitis and 1 meningitis) were reported in the control group ("standard hospital antibiotic protocol"). Mean length of hospitalization was 6.5 days for the case group and 8.5 days in the control group. "Standard hospital antibiotic protocol" is less expensive (range, 2.88-5.42 euros) compared with our new "nasal swab-related antibiotic protocol" (range, 10.02-32.56 euros), but in line with other antibiotic prophylaxis protocols reported in literature.. The low complication rates of our case series (0%) is comparable to complication rates reported in literature (1.6% for meningitis and 8% for sinusitis). Compared with other perioperative antibiotic regimens reported in literature, the "nasal swab-related antibiotic protocol" is cheap and at least equally effective. We discuss the rationale on which we based the choice of chemoprophylaxis, the timing, and the length of our regimen.. Our study confirmed the safety and efficacy of our easily applicable and low-cost antibiotic prophylaxis protocol.

Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Antibiotic Prophylaxis; Case-Control Studies; Cefazolin; Endoscopy; Female; Humans; Male; Meningitis; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Neurosurgical Procedures; Nose; Preoperative Care; Sinusitis; Skull Base; Staphylococcal Infections; Vancomycin; Young Adult

The concept of commensalism was introduced 145 years ago. The origin of the term comes from the Latin and embodies the concept of dining together. With a much deeper understanding of organisms that live with humans, a reassessment of what represents a commensal seems in order. This viewpoint article examines whether or not Staphylococcus aureus should still be considered a commensal. As a leading cause of serious community and hospital infections, removing the label "commensal" from S. aureus may help us to focus upon how to approach this organism, as the host response to this nasal colonizer is closer to mutually assured destruction rather than a friendly meal together.

Topics: Humans; Nose; Staphylococcal Infections; Staphylococcus aureus; Symbiosis

USA300 produces Panton-Valentin leucocidin (PVL) and is known as a predominant community-associated methicillin-resistant Staphylococcus aureus (MRSA) strain in the United States, but it was extremely rare in Japan. We report here an outbreak of USA300 in people with HIV (PWH) in Tokyo, Japan.. We analyzed the cases of PVL-MRSA infection between 2010 and 2020 and screened for nasal colonization of PVL-MRSA in PWH who visited an HIV/AIDS referral hospital from December 2019 to March 2020. Whole-genome sequencing-based single nucleotide polymorphism (SNP) analysis was performed on these isolates.. During the study period, a total of 21 PVL-MRSA infections in 14 patients were identified after 2014. The carriage prevalence was 4.3% (12/277) and PVL-MRSA carriers were more likely to have sexually transmitted infections (STIs) within a year compared with patients who had neither a history of PVL-MRSA infection nor colonization (33.3% [4/12] vs 10.1% [26/258]; P = .03). SNP analysis showed that all 26 isolates were ST8-SCCmecIVa-USA300. Twenty-four isolates were closely related (≤100 SNP differences) and had the nonsynonymous SNPs associated with carbohydrate metabolism and antimicrobial tolerance.. An outbreak of USA300 has been occurring among PWH in Tokyo and a history of STI was a risk of colonization.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Disease Outbreaks; Drug Resistance, Multiple, Bacterial; Genome, Bacterial; HIV Infections; Homosexuality, Male; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Typing; Nose; Phylogeny; Polymorphism, Single Nucleotide; Prevalence; Retrospective Studies; Sexually Transmitted Diseases; Staphylococcal Infections; Tokyo; Virulence Factors; Whole Genome Sequencing; Young Adult

Currently, antimicrobial-resistant staphylococci, particularly methicillin-resistant Staphylococcus pseudintermedius (MRSP), are frequently isolated from canine superficial pyoderma in Japan. However, little is known regarding the nasal prevalence of MRSP in pet dogs. Here, we determined the prevalence of antimicrobial-resistant staphylococci in nares and affected sites of pet dogs with superficial pyoderma. Of the 125 nares and 108 affected sites of pet dogs with superficial pyoderma, 107 (13 species) and 110 (eight species) staphylococci strains, respectively, were isolated. The isolation rate of S. pseudintermedius from pyoderma sites (82/110 strains, 74.5%) was significantly higher than that from nares (57/107 strains, 53.3%) (P<0.01). Notably, the prevalence of MRSP (18/57 strains, 31.6%) in nares was equivalent to that in pyoderma sites (28/82 strains, 34.1%). Furthermore, the phenotypes and genotypes of antimicrobial resistance in MRSP strains from nares were similar to those from pyoderma sites. Our findings revealed that the prevalence of antimicrobial-resistant staphylococci in the nares of pet dogs with superficial pyoderma is the same level as that in affected sites. Therefore, considerable attention should be paid to the antimicrobial resistance of commensal staphylococci in companion animals.

Topics: Animals; Anti-Infective Agents; Dog Diseases; Dogs; Drug Resistance, Bacterial; Japan; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Pets; Prevalence; Pyoderma; Staphylococcal Infections; Staphylococcus

Topics: Carrier State; Germany; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Prospective Studies; Risk Assessment; Risk Factors; Staphylococcal Infections; Travel-Related Illness

Nasal carriage of Staphylococcus aureus by healthcare workers is of great clinical importance as it facilitates the contamination of medical devices and cross-transmission. However, studies regarding the epidemiology and dissemination of S. aureus and Methicillin-resistant S. aureus (MRSA) within the Primary Health Care in Brazil are scarce. The current study aimed to detect and characterize S. aureus and MRSA strains from the nasal cavities of 63 healthcare working in primary health care units in order to determine the prevalence of S. aureus and MRSA, biofilm formation and resistance profile of these isolates. PCR reactions were performed for detecting mecA, icaA and icaD genes. The phenotypic antimicrobial susceptibility was assessed by the disk diffusion method and biofilm formation by the Congo Red Agar (CRA) method. The MRSA isolates were typed for the Staphylococcal Cassette Chromosome mec (SCCmec). The prevalence of nasal carriage of S. aureus was 74.6%, of which 72.3% were MRSA carrying SCCmec type I (24.4%), III (34.1%), IV (36.6%). Two (4.9%) isolates presented a non-typeable cassette by the performed technique. The antimicrobial susceptibility evaluation evidenced penicillin resistance in 66.1% of S. aureus, erythromycin resistance in 49.2%, while 37.3% were resistant to oxacillin, 28.8% to cefoxitin, 5.1% to levofloxacin and 5.1% to clindamycin. All isolates were biofilm producers and 96.6% of the strains contained the ica biofilm-forming genes (icaA and/or icaD). We have demonstrated a high prevalence of S. aureus and MRSA carriage among health care working in Primary Health Care units, the presence of SCCmec types I, III and IV, in addition to their high ability to form biofilm, factors that possibly contribute to the dissemination and persistence of these pathogens within the primary care services. These observations highlight the importance of broadening the perspective of Health Care-Associated Infections prevention, including all health care levels, which are currently little explored. In addition, the dynamics and resistance mechanisms of S. aureus transmission still need to be further clarified to enable the implementation of more effective prevention measures.

Topics: Adult; Anti-Bacterial Agents; Biofilms; Brazil; Carrier State; Cross Infection; Cross-Sectional Studies; Female; Genes, Bacterial; Health Personnel; Humans; Infectious Disease Transmission, Patient-to-Professional; Infectious Disease Transmission, Professional-to-Patient; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Primary Health Care; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

Topics: Bacterial Proteins; Cells, Cultured; Epithelial Cells; Gene Expression Regulation, Bacterial; Humans; Nose; Proteome; Staphylococcal Infections; Staphylococcus aureus; Temperature; Transcriptome; Virulence Factors

Nasal carriers of Staphylococcus aureus are at increased risk of postoperative surgical site infection. Nasal decolonization with mupirocin is recommended in patients undergoing cardiac surgery to reduce surgical site infection. These data are still lacking in Thailand. Therefore, the aim of this study was to determine the prevalence of S. aureus nasal carriage in Thai patients undergoing elective cardiac surgery. The association of surgical site infection and S. aureus nasal carriage was also examined.. This was a prospective cohort study of 352 patients who planned to undergo elective cardiac surgery. Nasal swab culture was performed in all patients preoperatively.. Of 352 patients, 46 (13.1%) had a positive nasal swab culture for methicillin-sensitive S. aureus (MSSA) and one patient (0.3%) harbored a methicillin-resistant S. aureus (MRSA) strain. The incidence of superficial and deep surgical site infection was 1.3% and 0.3%, respectively. After multivariate analysis, S. aureus nasal carriage was independently associated with superficial surgical site infection (odds ratio 13.04, 95% confidence interval 1.28-133.27; P=0.03).. The prevalence of MSSA and MRSA nasal carriage in Thai patients undergoing elective cardiac surgery was low. The incidence of surgical site infection was also very low in the population studied. Nevertheless, it was found that S. aureus nasal carriage increased the risk of superficial surgical site infection.

Topics: Elective Surgical Procedures; Humans; Incidence; Male; Middle Aged; Nose; Prevalence; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Previous studies indicate that the polymerase chain reaction (PCR) nasal assay for methicillin-resistant Staphylococcus aureus (MRSA) has a consistently high (>95%) negative predictive value (NPV) in ruling out MRSA pneumonia; however, optimal timing of PCR assay specimen and respiratory culture collection is unclear.. A study including 736 patients from a community hospital system was conducted. Patients were included if they had undergone MRSA nasal screening with a PCR assay and had documented positive respiratory culture results.. In the full cohort, the MRSA PCR nasal screen assay was demonstrated to have an NPV of 94.9% (95% confidence interval [CI], 92.8%-96.5%) in ruling out MRSA-positive respiratory cultures. When evaluating the NPV by level of care (ie, where the MRSA PCR nasal assay sample was collected), no significant difference between values for samples collected in an intensive care unit vs medical/surgical units was identified (NPV [95%CI], 94.9% [92.7%-96.6%] vs 95.3% [88.4%-98.7%]). Additionally, NPV remained high with use of both invasive (NPV [95%CI], 96.8% [92.7%-99.0%]) and noninvasive (NPV [95%CI], 94.5% [91.7%-96.2%]) respiratory sampling methods. Finally, when evaluating the effect of time between MRSA PCR nasal screening and respiratory sample collection, we found high NPVs for all evaluated timeframes: within 24 hours, 93.8% (90.1%-96.4%); within 25 to 48 hours, 98.6% (92.7%-100.0%); within 49 hours to 7 days, 95.7% (91.4%-98.3%); within 8 to 14 days, 92.9% (85.1%-97.3%); and after more than 14 days, 95.5% (84.5%-99.4%).. We report high NPVs for up to 2 weeks between specimen collections, which allows clinicians to use a negative MRSA PCR nasal screen assay to rule out MRSA pneumonia, potentially leading to decreased exposure to MRSA-active antibiotics.

Topics: Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Pneumonia, Staphylococcal; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections

Topics: Carrier State; Cellulitis; Child; Humans; Inpatients; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Staphylococcal Infections

The complications of endonasal transsphenoidal surgery (ETSS) include meningitis and sinusitis, and these complications are troublesome. Some reports have investigated the type of bacteria and the susceptibility of sphenoid sinus mucosal flora to drugs. However, most specimens can be collected after perioperative antibiotic administration. In this study, 95 and 103 sphenoid sinus mucosal samples collected during ETSS from September 2013 to February 2015 and from June 2017 to January 2019, respectively, were examined for bacterial culture. Sphenoid sinus mucosal samples were collected after antibiotic administration in the first period, whereas samples were collected before antibiotic administration in the second period. Hence, the specimens in the second period were not affected by antibiotics. Moreover, drug susceptibility tests for the detected bacteria were performed. Overall, 52 and 51 bacterial isolates were collected during both periods. Gram-positive cocci (GPCs), including Staphylococcus aureus and Staphylococcus epidermidis, were more common in the non-antibiotic group than in the antibiotic group (p <0.01). However, the proportion of gram-negative rods (GNRs) did not significantly differ between the two groups (p = 0.54). The antibiotic group had a significantly higher proportion of bacteria resistant to ampicillin (p <0.01) and first-generation cephalosporin (p = 0.01) than the non-antibiotic group. In conclusion, there was a difference in bacterial flora in the sphenoid sinus mucosal samples collected before and after intraoperative antibiotic administration.

Topics: Anti-Bacterial Agents; Bacteria; Humans; Nose; Sphenoid Sinus; Staphylococcal Infections

Enrichment culture (EC) remains gold standard for detecting MRSA colonisation, but molecular methods shorten turnaround time. The CE-marked automated Hologic Panther Fusion MRSA Assay (HPFM) is validated for nasal swabs. We compared HPFM with EC following an in-house PCR for detection of MRSA in nasal, pharyngeal, and perineal ESwabs. The same ESwabs were analysed using HPFM and inoculated in selective Tryptic Soy Broth (TSB) for overnight incubation. TSBs were screened by a PCR targeting nuc, femA, mecA, and mecC. Only samples with PCR results compatible with MRSA presence were inoculated onto 5% blood agar and chromogenic MRSA plates. HPFM detected MRSA in 103 of 132 EC positive samples indicating a sensitivity of 78.0% across sample types. When paired TSBs of 29 EC positive/HPFM negative samples were re-analysed by HPFM, MRSA was detected in 17/29 TSBs indicating that enrichment will increase the sensitivity of HPFM. HPFM analyses of cultured isolates from the remaining 12 EC positive/HPFM negative samples failed to detect orfX. HPFM reported the presence of MRSA in 22 samples where EC failed to identify MRSA. Fifteen of these ESwabs had been kept and direct culture without enrichment identified MRSA in seven samples. HPFM was useful for all sample sites. Compared to EC, the sensitivity of HPFM was limited because of lack of analytical sensitivity and failure to detect all MRSA variants. Failure of some MRSA-containing samples to enrich in cefoxitin-containing TSB indicates an unappreciated limitation of EC, which may lead to underestimation of the specificity of molecular assays.

Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Multiplex Polymerase Chain Reaction; Nose; Perineum; Pharynx; Staphylococcal Infections

To characterize the microbial communities of the anterior nares (nose) and posterior pharynx (throat) of adults dwelling in the community and in nursing homes before and after treatment with intranasal mupirocin.. Staphylococcus aureus-colonized adults were recruited from the community (n = 25) and from nursing homes (n = 7). S. aureus colonization was confirmed using cultures. Participants had specimens taken from nose and throat for S. aureus quantitation using quantitative PCR for the nuc gene and bacterial profiling using 16S rRNA gene sequencing over 12 weeks. After two baseline study visits 4 weeks apart, participants received intranasal mupirocin for 5 days with 3 further visits over a 8 week follow-up period.. We found a decrease in the absolute abundance of S. aureus in the nose for 8 weeks after mupirocin (1693 vs 141 fg/ul, p = 0.047). Mupirocin caused a statistically significant disruption in bacterial communities of the nose and throat after 1 week, which was no longer detected after 8 weeks. Bacterial community profiling demonstrated that there was a decrease in the relative abundance of S. aureus (8% vs 0.3%, p<0.01) 8 weeks after mupirocin and a transient decrease in the relative abundance of Staphylococcus epidermidis in the nose (21% vs 5%, p<0.01) 1 week after mupirocin.. Decolonization with mupirocin leads to a sustained effect on absolute and relative abundance of S. aureus but not for other bacteria in the nose. This demonstrates that a short course of mupirocin selectively decreases S. aureus in the nose for up to 8 weeks.

Topics: Administration, Intranasal; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Female; Homes for the Aged; Humans; Male; Microbiota; Middle Aged; Mupirocin; Nose; Nursing Homes; Pharynx; Staphylococcal Infections; Staphylococcus aureus

Drivers of pig trucks constitute a potential route of human transmission of livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398). In this study, we determined MRSA prevalence in pig truck drivers (

Topics: Adolescent; Adult; Agriculture; Animals; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbiota; Middle Aged; Motor Vehicles; Nose; RNA, Ribosomal, 16S; Staphylococcal Infections; Swine; Swine Diseases; Young Adult

Commensal flora colonization during hospitalization by bacteria is the first step for nosocomial infections while antibiotic resistance reduces therapeutic options. In aim to control this phenomenon, we initiated this study to describe the impact of hospitalization on colonization by methicillin-resistant Staphylococcus aureus in the surgical department of 03 health facilities in the Ndé division, West-Cameroon.. This study was carried out on patients admitted for surgery in 03 health facilities of the Ndé division, West-Cameroon (District Hospital of Bangangté, Protestant Hospital of Bangwa and Cliniques Universitaires des Montagnes). After obtaining ethical clearance and authorizations, nasal swabs were performed at admission and discharge, with the aim of isolating bacteria and performing their antibiotic susceptibility tests. Informations on each participant's antibiotic therapy were recorded. Laboratory investigations were carried out according to standard protocols (CASFM, 2019).. The most commonly used antibiotics were β-lactams. A total of 104 nasal swabs were performed on 52 patients who agreed to participate to the study. From the analysis, 110 (57 at admission versus 53 at discharge) Staphylococcus isolates were obtained. Overall, susceptibility testing showed that antibiotic resistance rates were higher at discharge than at admission; with significant differences between the susceptibility profiles obtained at admission and discharge for β-lactams and not significant for fluoroquinolones and aminoglycosides. Globally, frequency of nasal carriage of methicillin-resistant Staphylococcus aureus at discharge 16 (30.77%) was significantly higher than at admission 07 (13.46%) with Chi-2 = 4.52 and p = 0.0335.. The high rates of antibiotic resistance of bacteria isolated at discharge compared to those isolated at admission obtained in the present investigation, highlights the important role that hospitalization plays in the selection and dissemination of methicillin-resistant Staphylococcus aureus and colonization by these bacteria in health structures of Ndé division. As a result, further investigations to find the factors that promote this phenomenon should be carried out.

Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Cameroon; Child; Child, Preschool; Cross Infection; Cross-Sectional Studies; Female; Health Facilities; Hospitalization; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Previous studies have been unable to identify patient or staff reservoirs for the majority of the nosocomial S. aureus acquisitions which occur in the presence of good infection control practice. We set out to establish the extent to which undetected pre-existing carriage explains apparent nosocomial S. aureus acquisition.. Over two years elective cardiothoracic admissions were screened for S. aureus carriage before and during hospital admission. Routine screening (nose/groin/wound sampling), was supplemented by sampling additional body sites (axilla/throat/rectum) and culture-based methods optimised to detect fastidious phenotypes (small colony variants, cell wall deficient variants) and molecular identification by PCR.. 35% of participants (53/151) were S. aureus carriers according to routine pre-healthcare screening; increasing to 42% (63/151) when additional body sites and enhanced cultures were employed. 71% (5/7) of apparent acquisitions were explained by pre-existing carriage using augmented measures. Enhanced culture identified a minority of colonised individuals (3/151 including 1 MRSA carrier) who were undetected by routine and additional screening cultures. 4/14 (29%) participants who became culture-negative during admission had S. aureus genomic material detected at discharge.. Conventional sampling under-estimates carriage of S. aureus and this explains the majority of apparent S. aureus acquisitions among elective cardiothoracic patients.

Topics: Carrier State; Delivery of Health Care; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Staphylococcus aureus

Nasal swab culture is used to identify Staphylococcus aureus colonization, as this is a major risk factor for surgical site infection (SSI) in patients who are going to undergo major heart surgery (MHS). We determined nasal carriage of S. aureus in patients undergoing MHS by comparing the yield of a conventional culture with that of a rapid molecular test (Xpert® SA Nasal Complete, Cepheid).. From July 2015 to April 2017, all patients who were to undergo MHS were invited to participate in the study. We obtained two nasal cultures from each patient just before entering the operating room, independently of a previous test for the determination of nasal colonization by this microorganism performed before surgery. One swab was used for conventional culture in the microbiology laboratory, and the other was used for the rapid molecular test. We defined nasal colonization as the presence of a positive culture for S. aureus using either of the two techniques. All patients were followed up until hospital discharge or death.. Overall, 57 out of 200 patients (28.5%) were colonized by S. aureus at the time of surgery. Thirty-three patients had both conventional culture- and PCR-positive results. Twenty-four patients had a negative culture and a positive PCR test. Only twenty-one percent (12/57) of colonized patients had undergone an attempt to decolonise before the surgical intervention.. A significant proportion of patients undergoing MHS are colonized by S. aureus in the nostrils on entering the operating room. New strategies to prevent SSI by this microorganism are needed. Rapid molecular tests immediately before MHS, followed by immediate decolonisation, must be evaluated. Trial Registration Clinical Trials.gov NCT02640001.

Topics: Cardiac Surgical Procedures; Humans; Nose; Operating Rooms; Staphylococcal Infections; Staphylococcus aureus

Cases of colonization or infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) are frequently reported in people who work with animals, including veterinary personnel. The aim of this study was to determine the prevalence of MRSA colonization among veterinary professionals. A total of 134 nasal swabs from healthy attendees of a veterinary conference held in the Czech Republic were tested for presence of MRSA. The stains were further genotypically and phenotypically characterized.. Nine isolated MRSA strains were characterized with sequence type (ST), spa type (t) and Staphylococcal Cassette Chromosome mec type. Five different genotypes were described, including ST398-t011-IV (n = 5), ST398-t2330-IV (n = 1), ST398-t034-V (n = 1), ST225-t003-II (n = 1) and ST4894-t011-IV (n = 1). The carriage of the animal MRSA strain was confirmed in 8 cases, characteristics of one strain corresponded to the possible nosocomial origin. Among animal strains were described three spa types (t011, t034, t2330) belonging into one dominating clonal complex spa-CC11.. According to our results, the prevalence of nasal carriage of MRSA in veterinary personnel is 6.72%. Although we described an increase compared to the results of previous study (year 2008), the prevalence in the Czech Republic is still remaining lower than reported from neighboring countries. Our results also indicate that healthcare - associated MRSA strains are still not spread among animals.

Topics: Adult; Aged; Animals; Carrier State; Czech Republic; Education, Veterinary; Genotype; Humans; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Occupational Exposure; Prevalence; Staphylococcal Infections; Students; Veterinarians

Staphylococcus aureus is a frequent colonizer of human and several animal species, including dairy cows. It is the most common cause of intramammary infections in dairy cows. Its public health importance increases inline to the continuous emergence of drug-resistant strains; such as Methicillin-resistant S. aureus (MRSA). Indeed, the recent emergence of human and veterinary adapted MRSA demands serious attention. The aim of this study was to determine the burden and drug resistance pattern of S. aureus in dairy farms in Mekelle and determine the molecular characteristics of MRSA.. This study was done on 385 lactating dairy cows and 71 dairy farmers. The ages of the cows and farmworkers were between 3 and 14 and 17-63 years respectively. S. aureus was isolated from 12.5% of cows and 31% of farmworkers. Highest resistance was observed for penicillin (> 90%) followed by tetracycline (32-35%) and trimethoprim-sulphamethoxazole (10-27%). But no resistance was observed for vancomycin, daptomycin, and rifampin. Only one isolate was MRSA both phenotypically and harboring mecA. This isolate was from nasal of a farmworker and was MRSA SCCmec Iva, spa type t064 of CC8. Multi-drug resistance was observed in 6.2% of cow isolates and 13.6% of nasal isolates.. In this study, S. aureus infected 12.5% of dairy cows and colonized 31% of farmworkers. Except for penicillin, resistance to other drugs was rare. Although no MRSA was found from dairy cows the existence of the human and animal adapted and globally spread strain, MRSA SCCmec IVa spa t064, warrants for a coordinated action to tackle AMR in both human and veterinary in the country.

Topics: Adolescent; Adult; Animals; Cattle; Cross-Sectional Studies; Drug Resistance, Bacterial; Ethiopia; Farmers; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Milk; Nose; Staphylococcal Infections; Staphylococcus aureus

Rats are a reservoir of human- and livestock-associated methicillin-resistant

Topics: Animals; Animals, Wild; Anti-Bacterial Agents; Blood Coagulation; Czech Republic; Ecosystem; Germany; Methicillin; Molecular Epidemiology; Nose; Rats, Sprague-Dawley; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

Nasal colonization by coagulase-negative Staphylococci (CoNS) play an important role in nosocomial infections. This study aims to determine antibiotics susceptibility pattern and molecular screening of methicillin- and vancomycin-resistant nasal CoNS among hospitalized patients.. Nasal swabs were collected from 202 inpatients at Prince Hamzah Hospital, Jordan. Swabs were processed according to standard microbiological procedures to isolate Staphylococci. Antibiotic susceptibility testing was performed using disk diffusion, E-test, microdilution, and Vitek 2. Molecular analysis was performed using PCR for the detection of mecA, vanA, and vanB genes.. Nasal Staphylococci was isolated in 64/202 (31.7%) samples. Thirty isolates (14.8%) were CoNS, including S. haemolyticus (n = 17, 8.4%), S. sciuri (n = 6, 3%), S. epidermidis (n = 2, 1%), S. warneri (n = 2, 1%), S. hominis (n = 2, 1%), and S. lentus (n = 1, 0.5%). Twenty-two (10.9%) isolates were MR-CoNS harboring mecA gene. CoNS and MR-CoNS isolates were highly resistant to benzylpenicillin, erythromycin, fosfomycin, and imipenem. All isolates were sensitive to vancomycin by E-test and microdilution test and were negative for vanA and vanB genes. Nasal CoNS colonization was associated with an increased number of family members living with the participant (P = 0.04) and with admission to the orthopedic department (P = 0.03), while MR-CoNS colonization was associated with smoking (P = 0.03).. Nasal colonization by unusual CoNS species and mecA-positive MR-CoNS are common among hospitalized patients. Absence of vanA and vanB genes suggests little contribution of nasal CoNS to vancomycin resistance transmission.

Topics: Adult; Aged; Anti-Bacterial Agents; Coagulase; Cross Infection; Cross-Sectional Studies; Drug Resistance, Bacterial; Female; Hospitalization; Humans; Jordan; Male; Methicillin; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Staphylococcus; Vancomycin

Nasal colonization of Staphylococcus aureus is a risk factor for the pathogen transmission and the development of infections. Limited information is available on the prevalence and molecular characteristics of S. aureus colonization in pediatric intensive care unit (ICU) patients.. A cross-sectional, island-wide study was conducted in 2011. Nasal swabs were collected from pediatric ICU patients at six tertiary hospitals in Taiwan.. Of 114 patients enrolled in total, nasal colonization of S. arueus was detected in 30 (26.3%) of them, among whom 20 (17.5%) with methicillin-resistant S. arueus (MRSA). The ST59/SCCmec IV and V clones were most common and accounted for 45% of MRSA isolates, followed by ST239/SCCmec III (25%) and ST45/SCCmec IV (20%) clones. Three ST59 MRSA isolates carried the Panton-Valentine Leukocidin genes.. The results indicated a high prevalence of S. arueus and MRSA nasal colonization among pediatric ICU patients in Taiwan. Identification of epidemic clones warrants the implement of infection control measures to reduce colonization and prevent the dissemination of MRSA in hospitals.

Topics: Adolescent; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cross-Sectional Studies; Exotoxins; Female; Humans; Infant; Leukocidins; Male; Methicillin Resistance; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Phylogeny; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Taiwan; Tertiary Care Centers

Staphylococcus aureus (S. aureus), particularly methicillin-resistant Staphylococcus aureus (MRSA), remains the predominant cause of infections in drug users. This cross-sectional study aims to elucidate the prevalence, risk factors, phenotypic and molecular characteristics of S. aureus carriage among community-based drug users.. All eligible drug users, with both injection and non-injection route of drug administration, were asked to complete questionnaires and collect nasal swabs by trained personal during the period between May and December 2017 in Guangzhou, China. Swabs were processed for identification of S. aureus. Antimicrobial susceptibility test and polymerase chain reaction assays were used to detect phenotypic and molecular characteristics for identified isolates. Univariate and multivariate logistic regression analyses were used to assess risk factors for S. aureus carriage.. Overall, 353 drug users were included in the study and the prevalence of S. aureus carriage was 15.01% (53/353). The prevalence of MRSA carriage was 6.80% (24/353). Cohabitation was a risk factor for S. aureus (adjusted OR = 8.80, 95% CI: 1.89-40.99). The proportion of multidrug resistance was 54.72% for S. aureus isolates and most of these isolates were resistant to penicillin, erythromycin and clindamycin. Seventeen MRSA isolates were multidrug resistant. The results of clonal complexes (CCs) and sequence types (STs) for S. aureus were diverse. The three predominant types for CCs were CC5 (64.15%, 34/53), CC59 (11.32%, 6/53), and CC7 (7.55%, 4/53); and for STs were ST188 (20.75%, 11/53), ST5 (11.32%, 6/53), and ST59 (11.32%, 6/53).. The prevalence of S. aureus nasal carriage was lower while the prevalence of MRSA carriage was moderate compared to previous studies. Phenotypic and molecular characteristics of S. aureus isolates, particularly MRSA isolates, revealed high proportions of antibiotic resistance, indicating the existence of cross-circulation, and implying high opportunity of virulence-related diseases. Decolonization and antibiotic stewardship might be implemented for drug users with MRSA carriage.

Topics: Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; China; Clindamycin; Community-Acquired Infections; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Drug Users; Erythromycin; Female; Humans; Logistic Models; Male; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Penicillins; Phenotype; Phylogeny; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires

The aim of this study was to detect the frequency of methicillin-resistant Staphylococcus aureus (MRSA) colonization at admission in a group of presumably high-risk international or Turkish patients referred to our center for elective operations, some of whom were from countries with an unknown prevalence of MRSA infection or colonization.. The results of nasal swab screening for MRSA colonization performed using a specific algorithm between 2011 and 2018 in a private medical center were retrospectively reviewed. Presence of MRSA was ascertained using culture and/or real-time polymerase chain reaction (real-time PCR).. A total of 3,795 patients were included in the study. More than half of the patients were ≤19 years of age (2,094, 55.2%), and MRSA positivity was more common among these patients. Turkish patients constituted 24.5% of the study population. International patients were most frequently referred from Iraq (55.92%), Libya (11.44%), Romania (2.69%), and Bulgaria (1.98%). MRSA positivity was significantly more common among patients referred from other countries when compared to Turkish nationals (11.5% vs. 4.4%, P = 0.00001). Countries with the highest prevalence rates of MRSA colonization were as follows with decreasing order: United Arab Emirates, 25.0%; Georgia, 23.1%; Russia, 22.7%; Iraq, 13.0%, Romania, 12.7%. Other countries with high number of admitted patients (>70 patients) had the following MRSA rates: Turkey, 4.4%; Libya, 6.0%; Bulgaria, 5.3%.. Although MRSA has a low prevalence in our center, a variation in the rate of MRSA positivity was observed across patients from different countries. Absence hospital acquired contamination or outbreaks in our institution may be attributed to the screening algorithm used and underscores the importance of risk analysis for patients referred from geographical locations with unknown MRSA frequency, to reduce the risk of transmission.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Load; Bulgaria; Child; Child, Preschool; Cross Infection; Female; Hospitalization; Human Migration; Humans; Infant; Iraq; Libya; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Polymerase Chain Reaction; Prevalence; Risk Factors; Romania; Staphylococcal Infections; Tourism; Turkey; United Arab Emirates; Young Adult

There have been few reports on the genetic structure of the current population of methicillin-resistant Staphylococcus aureus (MRSA) from neonatal intensive care units (NICUs) in Japan. In the present study we conducted a molecular epidemiological analysis based on whole genome sequencing against MRSA strains in a Japanese NICU.. We performed genotyping by whole genome sequencing, polymerase chain reaction-based typing of Staphylococcal cassette chromosome mec (SCCmec) and polymerase chain reaction-based open-reading frame typing against 57 MRSA strains from fecal or nasal specimens from NICU patients in Juntendo University Shizuoka Hospital in 2013-2014.. Forty-nine MRSA strains (86.0%) exhibited a clonal complex (CC) 1, and were divided into three sequence types (STs): ST2725 (n = 25), ST2764 (n = 21), and ST1 (n = 3). All CC1 MRSA strains had SCCmec IVa, and were resistant to new quinolones, which are limited in pediatric use, suggesting that these strains were derived from adult MRSA clones. Single nucleotide polymorphism differences of both ≤10 and >100 nucleotides were observed by pairwise, single nucleotide polymorphism analysis among ST2725 and ST2764 MRSA strains, respectively. Seven ST8 MRSA strains (12.2%) were isolated, and no strain exhibiting the Japanese hospital-associated MRSA genotype (ST5/SCCmec II) was isolated in this study.. Our molecular epidemiological analysis suggested that ST2725 and ST2764 MRSA strains had genetic diversity that could not be explained only by a recent transmission event in the NICU. These MRSA clones might be disseminated in other Japanese hospital facilities as new endemic clones. Our results are expected to contribute to the improvement of infection control measures of MRSA in NICUs.

Topics: Feces; Genotype; Humans; Infant, Newborn; Infection Control; Intensive Care Units, Neonatal; Japan; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Nose; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Staphylococcal Infections; Whole Genome Sequencing

Since its emergence in the early 2000s, livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) has led to an increasing number of human infections in Denmark and other European countries with industrial pig production. LA-MRSA CC398 is primarily associated with skin infections among pig farm workers but is also increasingly recognized as a cause of life-threatening disease among elderly and immunocompromised people. Pig farm workers may serve as vehicles for the spread of LA-MRSA CC398 and other farm-origin bacteria between farms and into the general population. Yet, little is known about the bacterial community dynamics in pig farm workers and other persons with long- and short-term exposure to the pig farm environment. To gain insight into this, we investigated the nasal microbiomes in pig farm workers during a workweek on four LA-MRSA CC398-positive pig farms, as well as in short-term visitors two hours before, immediately after, and 48 hours after a 1-hour visit to another LA-MRSA CC398-positive pig farm. S. aureus and LA-MRSA CC398 carriage was quantified by means of culture, and the composition of the bacterial communities was investigated through sequencing of the 16S rRNA gene. Pig farm workers often carried LA-MRSA CC398 and other bacteria from the pig farm environment, both at work and at home, although at lower levels at home. In contrast, short-term visitors were subject to a less dramatic and rapidly reversible change in the nasal bacterial community composition. These results suggest that pig farm workers may be an important source of LA-MRSA CC398 and perhaps other pathogens of human and veterinary relevance.

Topics: Adult; Animals; Carrier State; DNA, Bacterial; Farms; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbiota; Middle Aged; Nose; Occupational Exposure; RNA, Ribosomal, 16S; Staphylococcal Infections; Swine; Time Factors; Young Adult

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a microorganism that colonizes nostrils and different parts of the body, which is considered a risk factor to acquire invasive infections, especially in cardiovascular surgery patients.\ Objective: To determine the frequency of nasal colonization by MRSA and to establish the clinical characteristics in patients scheduled for cardiovascular surgery.\ Materials and methods: This was a descriptive study conducted between February and December, 2015. We included adult patients scheduled for cardiovascular surgery at the Hospital Universitario San Ignacio in Bogotá, Colombia. Colonization was identified by real-time PCR from nasal swabs. Colonized patients were treated with mupirocin 2.0% intranasally twice a day and bathed with chlorhexidine 4% from the neck downwards for five days. At the end of this treatment, PCR control was carried out.\ Results: We included 141 patients with a percentage of nasal colonization of 13.4% (19/141). There were 52 hospitalized patients and 89 outpatients with a percentage of nasal colonization of 17.3% (9/52), and 11.2% (10/89), respectively. All colonized patients who received treatment had a negative PCR at the end of the regime and none of the participating patients had a surgical site infection by S. aureus at the end of the study.\ Conclusions: Nasal colonization was observed both in hospitalized patients and outpatients. Decolonization treatment with mupirocin was effective to eradicate the carrier state in the short term, which could impact the rates of surgical wound infection associated with cardiovascular surgery.. Introducción. Staphylococcus aureus resistente a la meticilina (SARM) es un microorganismo que coloniza las fosas nasales y diferentes partes del cuerpo, lo cual se considera un factor de riesgo para adquirir infecciones invasivas, especialmente en pacientes sometidos a cirugía cardiovascular. Objetivo. Determinar la colonización nasal por SARM y establecer las características clínicas en pacientes programados para cirugía cardiovascular. Materiales y métodos. Se hizo un estudio descriptivo entre febrero y diciembre de 2015. Se incluyeron pacientes adultos programados para cirugía cardiovascular en el Hospital Universitario San Ignacio de Bogotá. La colonización se identificó mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en tiempo real en muestras obtenidas mediante hisopados nasales. Los pacientes fueron descolonizados con mupirocina al 2,0 % intranasal dos veces al día y baños con gluconato de clorhexidina al 4 % del cuello hacía abajo durante cinco días, al cabo de lo cual se hizo una PCR de control. Resultados. Se incluyeron 141 pacientes, 52 hospitalizados y 89 ambulatorios. Del total, 19 (13,4 %) tenían colonización nasal por SARM, correspondientes a 9 (17,3 %) de los 52 hospitalizados y 10 (11,2 %) de los 89 ambulatorios. Todos los pacientes sometidos a descolonización tuvieron resultado negativo en la PCR al final del proceso y ninguno presentó infección del sitio operatorio por S. aureus. Conclusiones. Se demostró colonización nasal por SARM tanto en los pacientes hospitalizados como en los ambulatorios. La descolonización con mupirocina fue efectiva para erradicar el estado de portador a corto plazo, lo que podría tener efecto en las tasas de infección del sitio operatorio en las cirugías cardiovasculares.

Topics: Aged; Cardiovascular Surgical Procedures; Colombia; Female; Hospitals, University; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Postoperative Complications; Preoperative Period; Staphylococcal Infections

Panton-Valentine leukocidin (PVL)-positive USA300 clone is a highly pathogenic and global epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone. Athletes are particularly vulnerable to CA-MRSA infection because of the frequency of skin trauma, close-contact situations, and sharing of equipment that is customary in the athletic setting. We experienced a case of Japanese collegiate football player with septic pulmonary emboli secondary to infectious iliofemoral deep venous thrombosis caused by the USA300 clone. Here, we screened the nasal carriage of USA300 clone colonization among asymptomatic teammate of the patient to elucidate the infection route. Among 69 nasal samples, CA-MRSA strains were found in 5.8% (four samples). Molecular epidemiological analyses showed that three of the CA-MRSA strains were USA300 clone. Furthermore, pulsed-field gel electrophoresis revealed that all nasal USA300 clones showed 100% identity with the USA300 clone isolated from their teammate with critical infection. Our findings indicate that nasal colonization of the PVL-positive CA-MRSA, especially USA300 clone, pose a threat among contact sport athletes in Japan likewise other countries. An immediate infection control strategy for contact sport athletes is necessary to prevent outbreaks of PVL-positive CA-MRSA infections.

Topics: Anti-Bacterial Agents; Asymptomatic Infections; Athletes; Bacterial Toxins; Community-Acquired Infections; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Humans; Japan; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Nose; Soccer; Sports; Staphylococcal Infections; Universities; Young Adult

Engineered luciferase reporter bacteriophages provide specific, sensitive, rapid and low-cost detection of target bacteria and address growing diagnostic needs in multiple industries. Detection of methicillin-resistant

Topics: Bacteriophages; Diagnostic Techniques and Procedures; Genes, Reporter; Humans; Luciferases; Methicillin-Resistant Staphylococcus aureus; Nose; Sensitivity and Specificity; Staphylococcal Infections

Surgical-site infection following complicated septorhinoplasty may result in serious complications. Therefore, efforts to prevent surgical-site infections after complicated septorhinoplasty are important. The purpose of this study was to analyze the microbiological profile of preoperative nasal swab cultures and to evaluate the effect of antibiotic prophylaxis and topical antibiotic decolonization according to the antibiotic sensitivity results of surgical-site infections in complicated septorhinoplasty.. This 10-year cohort study included the data on 437 consecutive patients who underwent complicated septorhinoplasty. The patients were categorized into three cohorts based on the time of preoperative nasal swab culture collection. Patients in cohort 1 did not undergo nasal swab cultures and received empirical antibiotics. Patients in cohort 2 underwent only one preoperative nasal swab culture and received microorganism-sensitive antibiotics. Patients in cohort 3 underwent repeated nasal swab cultures. The antibiotics were changed when microorganisms resistant to the empirical antibiotics were isolated. Microbiological data and the rates of surgical-site infection and inflammation were compared among the three cohorts.. Methicillin-sensitive Staphylococcus aureus was the most commonly isolated microorganism. In cohort 1, two (5 percent) and two (5 percent) patients experienced surgical-site infections and inflammation, respectively. In cohort 2, two (3 percent) and three (4 percent) patients experienced surgical-site infections and inflammation, respectively. In cohort 3, one (0.3 percent) and one (0.3 percent) patient experienced surgical-site infection and inflammation, respectively.. The present study demonstrated that preoperative screening using repeated nasal swab cultures, followed by appropriate antibiotic prophylaxis and topical antibiotic decolonization, may reduce surgical-site infection in complicated septorhinoplasty.. Therapeutic, III.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Antibiotic Prophylaxis; Cohort Studies; Female; Humans; Male; Mass Screening; Middle Aged; Nose; Postoperative Complications; Preoperative Care; Rhinoplasty; Staphylococcal Infections; Surgical Wound Infection; Young Adult

Staphylococcus aureus (SA) nasal carriage screening is usually based on either culture or molecular biology. The aim of the study was to evaluate the performance of the Panther Fusion® MRSA Assay (PF) that proposes a complete automation of the molecular screening for MSSA and MRSA carriage. Four hundred thirty-four nasal samples collected on ESwab™ were screened using PF. Results were compared with standard culture on BBL™ CHROMagar™ Staph aureus and chromID® MRSA agar. Discordant results were analyzed with additional techniques: Xpert SA Nasal Complete on GeneXpert (GX), culture on selective agar after 24 h in broth enrichment, and, if necessary, characterization of mec gene and SCCmec cassette using DNA microarray. The PF presented an overall agreement of 97.5% for SA detection and 97.9% for MRSA detection. Furthermore, 7.1% (31/434) of the samples were SA-negative in primary culture but SA-positive using PF and GX, confirming the greater sensitivity of molecular tests compared with culture. Of note, 4 out of 30 MRSA-positive samples were not detected due to an atypical SCCmec cassette, while 2 samples were falsely detected as MRSA due to co-colonization with a MSSA drop-out strain and a methicillin-resistant coagulase-negative staphylococcal strain. Considering all results, the PF instrument appears as a reliable and rapid (< 3 h) package for MSSA/MRSA nasal screening. This technology using random access capability and direct sampling of the primary container is innovative and corresponds therefore to a new step in complete molecular biology automation in bacteriology.

Topics: Bacterial Proteins; Carrier State; Diagnostic Tests, Routine; France; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Penicillin-Binding Proteins; Predictive Value of Tests; Prospective Studies; Specimen Handling; Staphylococcal Infections

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) is associated with an increased risk of infection. Colonization with MRSA is observed in < 1% of the general Dutch population. Increased risk for MRSA carriage is known to occur in several key groups, one of which is asylum seekers. However, little is known about MRSA carriage among undocumented migrants and uninsured legal residents. This study aimed to determine the prevalence of nasal MRSA carriage among these groups in Amsterdam, the Netherlands.. In this cross-sectional study, between October 2018 and October 2019, undocumented migrants and uninsured legal residents aged 18 years or older who were able to understand one of the study languages were recruited at an NGO health care facility in Amsterdam, the Netherlands, for general practitioner (GP) consultations. Participants were asked questions on demographics, migration history, antibiotic use and other possible risk factors for MRSA carriage and were screened for nasal MRSA carriage by selective culturing e-swabs. Characteristics of MRSA-negative and MRSA-positive participants were compared using univariable logistic regression analysis with Firth's correction.. Of the 3822 eligible patients, 760 were screened for nasal MRSA carriage (19.9%). Of the 760 participants, over half were male (58%; 442/760) and originated mainly from Africa (35%; 267/760), Asia (30%; 229/760) and North or South America (30%; 227/760). In total, 705/760 participants (93%) were undocumented migrants and 55/760 (7%) were uninsured legal residents of Amsterdam. The overall prevalence of nasal MRSA carriage was 2.0% (15/760) (95%CI 1.1 to 3.2%), with no difference between undocumented migrants (14/705) (2.0, 95%CI 1.1 to 3.3%) and uninsured legal residents (1/55) (1.8, 95%CI 0.1 to 9.7%). Genotyping showed no clustering of the 15 isolates. MRSA carriage was not associated with sociodemographic, migration history or other possible risk factors. Nevertheless, this study had limited power to detect significant determinants. Three participants (3/15; 20%) harbored Panton-Valentine leukocidin (PVL)-positive isolates.. Even though our study population of undocumented migrants and uninsured legal residents had a higher prevalence of nasal MRSA carriage compared to the general Dutch population, the prevalence was relatively low compared to acknowledged other high-risk groups.

Topics: Adult; Aged; Carrier State; Cross-Sectional Studies; Female; Humans; Male; Medically Uninsured; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Netherlands; Nose; Prevalence; Staphylococcal Infections; Undocumented Immigrants

The objectives of this study were to determine for the first time, in Morocco, the nasal carriage rate, antimicrobial susceptibility profiles and virulence genes of Staphylococcus. aureus isolated from animals and breeders in close contact.. From 2015 to 2016, 421 nasal swab samples were collected from 26 different livestock areas in Tangier. Antimicrobial susceptibility phenotypes were determined by disk diffusion according to EUCAST 2015. The presence of nuc, mecA, mecC, lukS/F-PV, and tst genes were determined by Polymerase Chain Reaction (PCR) for all isolates.. The overall S. aureus nasal carriage rate was low in animals (9.97%) and high in breeders (60%) with a statistically significant difference, (OR = 13.536; 95% CI = 7.070-25.912; p < 0.001). In general, S. aureus strains were susceptible to the majority of antibiotics and the highest resistance rates were found against tetracycline (16.7% in animals and 10% in breeders). No Methicillin-Resistant S. aureus (MRSA) was detected in animals and breeders. A high rate of tst and lukS/F-PV genes has been recovered only from animals (11.9 and 16.7%, respectively).. Despite the lower rate of nasal carriage of S. aureus and the absence of MRSA strains in our study, S. aureus strains harbored a higher frequency of tst and lukS/F-PV virulence genes, which is associated to an increased risk of infection dissemination in humans. This highlights the need for further larger and multi-center studies to better define the transmission of the pathogenic S. aureus between livestock, environment, and humans.

Topics: Animals; Animals, Domestic; Anti-Bacterial Agents; Bacterial Proteins; Carrier State; Drug Resistance, Bacterial; Humans; Leukocidins; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Micrococcal Nuclease; Morocco; Nose; Penicillin-Binding Proteins; Staphylococcal Infections; Staphylococcus aureus; Tetracycline; Virulence

The objective was to describe French hospital nasal screening and decolonization procedures before clean surgery procedures. Information for participants was sent to the French Society for Infection Control members in June 2018. Seventy hospitals participated in the survey; 40% (N = 28) declared having institutional decolonization procedures: 64% (N = 18) in orthopaedic and 56% (N = 15) in cardiac surgeries. All hospitals used mupirocin for nasal decolonization and body decolonization with chlorhexidine (N = 16) or povidone iodine (N = 10). This study is the first to be performed in France giving information in this field. Screening/decolonization procedures are heterogeneous and the evaluation of their clinical impact remains complex.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Chlorhexidine; Decontamination; France; Humans; Infection Control; Mupirocin; Nose; Orthopedic Procedures; Povidone-Iodine; Qualitative Research; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Surveys and Questionnaires; Thoracic Surgical Procedures

Topics: Adult; Bacteria; Bacterial Adhesion; Carrier State; Epithelial Cells; Female; Humans; Male; Microbiota; Nasal Cavity; Nasal Mucosa; Nose; Staphylococcal Infections; Staphylococcus aureus

Colonization of methicillin-resistant Staphylococcus aureus (MRSA) can be detected via nasal screens. Evidence indicates that negative MRSA nasal screens may be used to de-escalate anti-MRSA antibiotics in pulmonary infections. In the ICU, universal decolonization with intranasal mupirocin is implemented to reduce MRSA infection risk. This study aimed to determine whether mupirocin administration affects the reliability of MRSA PCR nasal screens.. This retrospective study divided subjects based on timing of intranasal mupirocin administration-before and after MRSA screen. Subjects with confirmed pulmonary infection that received vancomycin, blood/respiratory cultures, and had MRSA PCR screen collected were included. Subjects with concurrent infection requiring vancomycin or MRSA infection in prior 30 days were excluded. Primary outcome of this non-inferiority study was the negative predictive value (NPV) of the screen. Secondary outcomes included the positive predictive value (PPV), sensitivity, and specificity of the screen and duration of vancomycin.. Ultimately, 125 subjects were included in each group. The NPV in the group receiving mupirocin before screen was 95.2%, whereas the NPV in the group receiving mupirocin after screen was 99%. The difference between groups was -3.8% (90% CI -7.8%-0.2%; p=0.31), which failed to meet non-inferiority criteria. The secondary outcomes of PPV, sensitivity and specificity of the screen were similar in both groups. The duration of vancomycin was significantly longer in subjects receiving mupirocin before screen (3 days vs. 2 days; p<0.05).. Intranasal mupirocin prior to the screen may reduce NPV in pulmonary infections. Approach de-escalation of vancomycin based on screen results with caution.

Topics: Administration, Intranasal; Aged; Anti-Bacterial Agents; Cohort Studies; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mupirocin; Nose; Polymerase Chain Reaction; Reproducibility of Results; Retrospective Studies; Staphylococcal Infections; Vancomycin

Preoperative nasal. All primary total hip arthroplasties (THA) and total knee arthroplasties (TKA) performed from January 2006 to April 2018 were retrospectively reviewed for the incidence of early PJI. Demographic parameters, risk factors for PJI (American Society of Anaesthesiologists classification, body mass index, smoking status, and diabetes mellitus) and implant types were collected. A preoperative screening and eradication protocol for nasal colonization of. In total, 10,486 THAs and TKAs were performed in the research period. After exclusion, a cohort of 5,499 screened cases and 3,563 non-screened cases were available for analysis. Overall, no significant reduction in early PJI was found in the screened group (odds ratio (OR) 0.78, 95% confidence interval (CI) 0.55 to 1.11; p = 0.173). However, the incidence of. A preoperative nasal

Topics: Aged; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Female; Humans; Male; Mass Screening; Nose; Preoperative Period; Retrospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

This study investigated Staphylococcus aureus carriage in patients with microbial keratitis (MK). 215 patients with MK, 60 healthy controls and 35 patients with rheumatoid arthritis (RA) were included. Corneal scrapes were collected from patients with MK. Conjunctival, nasal and throat swabs were collected from the non-MK groups on a single occasion and from the MK group at presentation and then at 6 and 12 weeks. Samples were processed using conventional diagnostic culture. 68 (31.6%) episodes of clinically suspected MK were classed as recurrent. Patients with recurrent MK had a higher isolation rate of S. aureus from their cornea than those with a single episode (p < 0.01) and a higher isolation rate of S. aureus from their conjunctiva compared to control participants, 20.6% (14/68) versus 3% (5/60) respectively (p = 0.01). Significantly more patients with recurrent MK (12/68, 17.6%) were found to have S. aureus isolated from both their conjunctiva and nose than those with a single episode of MK (7/147, 4.8% p = 0.002) and compared to patients in the control group (3/60, 5.0% p = 0.03). The results indicate that patients with recurrent MK have higher rates of carriage of S. aureus suggesting endogenous site colonisation as a possible source of recurrent infection.

Topics: Arthritis, Rheumatoid; Cornea; Diagnostic Tests, Routine; Female; Humans; Keratitis; Male; Middle Aged; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

Topics: Dermatologists; Habits; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is a leading cause of healthcare- and community-associated infections and can be difficult to treat due to antimicrobial resistance. About 30% of individuals carry S. aureus asymptomatically in their nares, a risk factor for later infection, and interactions with other species in the nasal microbiome likely modulate its carriage. It is thus important to identify ecological or functional genetic elements within the maternal or infant nasal microbiomes that influence S. aureus acquisition and retention in early life.. We recruited 36 mother-infant pairs and profiled a subset of monthly longitudinal nasal samples from the first year after birth using shotgun metagenomic sequencing. The infant nasal microbiome is highly variable, particularly within the first 2 months. It is weakly influenced by maternal nasal microbiome composition, but primarily shaped by developmental and external factors, such as daycare. Infants display distinctive patterns of S. aureus carriage, positively associated with Acinetobacter species, Streptococcus parasanguinis, Streptococcus salivarius, and Veillonella species and inversely associated with maternal Dolosigranulum pigrum. Furthermore, we identify a gene family, likely acting as a taxonomic marker for an unclassified species, that is significantly anti-correlated with S. aureus in infants and mothers. In gene content-based strain profiling, infant S. aureus strains are more similar to maternal strains.. This improved understanding of S. aureus colonization is an important first step toward the development of novel, ecological therapies for controlling S. aureus carriage.

Topics: Carnobacteriaceae; Female; Humans; Infant; Metagenomics; Microbiota; Mothers; Nose; RNA, Ribosomal, 16S; Staphylococcal Infections; Staphylococcus aureus; Streptococcus

Respiratory infections are a leading cause of morbidity and mortality worldwide. Bacterial pathogens often colonize the upper respiratory tract (nose or mouth) prior to causing lower respiratory infections or invasive disease. Interactions within the upper respiratory tract between colonizing bacteria and the resident microbiota could contribute to colonization success and subsequent transmission. Human carriage studies have identified associations between pathogens such as

Topics: Animals; Disease Models, Animal; Female; Mice; Mice, Inbred C57BL; Microbiota; Nasal Cavity; Nose; Pneumococcal Infections; Respiratory Tract Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Proteins; Biofilms; Female; Gene Expression Regulation, Bacterial; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Staphylococcal Infections; Virulence Factors; Young Adult

To evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in patients with diabetic foot ulcer (DFU) in Taiwan, and to assess the concordance between colonizing and clinical MRSA isolates from the patients.. A total of 354 nasal specimens were collected from 112 to 242 diabetic patients with and without foot ulcer, respectively. MRSA clinical isolates from DFU wound cultures were collected for comparison.. Nasal carriage rate of S. aureus and MRSA was similar between diabetic patients with and without foot ulcer (15.2% vs. 16.9% for S. aureus and 5.4% vs. 1.7% for MRSA). Nasal S. aureus colonization was an independent predictor for wound S. aureus infection (Odds ratio [OR]: 5.33, 95% confidence interval [CI]: 1.61-17.59), so did nasal MRSA colonization (OR: 19.09, 95% CI: 2.12-171.91). The levels of glycated hemoglobin, and the usage with immunosuppressant agent were associated with S. aureus nasal colonization while oral hypoglycemic agent usage a protective factor. Sequence type 59/staphylococcal chromosome cassette mec IV or V, the local endemic community-associated clone, accounted for 42% and 70% of the clinical and colonizing isolates, respectively. Six of 10 patients with paired colonizing and clinical isolates, either MRSA or methicillin-sensitive S. aureus, had a genetically identical strain from a single patient.. Less than one-fifth of patients with DFU have nasal S. aureus, including MRSA, colonization; however, the colonization is significantly associated with S. aureus diabetic foot infection. Screening for S. aureus colonizing status in DFU patients might have a potential clinical implication.

Topics: Animals; Carrier State; Diabetes Complications; Diabetes Mellitus; Diabetic Foot; Humans; Logistic Models; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Taiwan

Thirty percent of the general population are Staphylococcus aureus nasal carriers. It has been shown that this increases with repeated contact with patients, but it is not known whether all categories of healthcare workers are at equal risk of carriage. We aimed to explore S. aureus nasal carriage among healthcare professionals.. Prospective study conducted in two French university hospitals in 2014 and 2016. Volunteers were screened for S. aureus nasal carriage. Profession and hygiene habits were collected. Based on the results of this initial study, a second study focused on semi-skilled workers and biomedical equipment technicians (BETs) only; participants were given education on the basic rules of hygiene, then re-screened three months later.. In the initial study, 38.8% of the 436 participants were detected as nasal carriers. There was a significant difference in nasal carriage according to professional category (p < 0.0001); the lowest was found among administrative agents (17.3%), followed by healthcare providers (37.4%), laboratory technicians (37.6%). The greatest proportion was found among semi-skilled workers and BETs (52.9%). Spa-typing ruled out the hypothesis of a single clone dissemination among colleagues. After the three-month hygiene awareness campaign, all re-screened individuals remained positive, and with their respective initial strain.. To the best of our knowledge we report here for the first time that semi-skilled workers and BETs are specifically more at risk of S. aureus nasal colonisation. This striking finding urges hospital hygiene departments to evaluate this specific professional category and implement strategies to improve hygiene awareness.

Topics: Adult; DNA, Bacterial; Female; France; Health Personnel; Hospitals, University; Humans; Male; Middle Aged; Nose; Risk; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a leading cause of hospitalization and medical visits among individuals experiencing homelessness and also among persons who inject drugs (PWID), populations with significant overlap in urban centers in the USA. While injection drug use is a risk factor for MRSA skin infections, MRSA is also known to transmit easily in crowded, public locations in which individuals have reduced personal hygiene. Individuals in urban centers who experience homelessness or drug addiction may spend significant amounts of time in environments where MRSA can be easily transmitted, and may also experience reduced access to facilities to maintain personal hygiene. We assessed the relationship between homelessness, personal hygiene, and MRSA nasal colonization, a proxy for MRSA infection risk, in a study of PWID in Boston, MA (n = 78). Sleeping in a homeless shelter for at least one night in the last 3 months was significantly associated with MRSA nasal colonization (OR 3.0; p = 0.02; 95% CI 1.2, 7.6). Sleeping at more than one place during the last week (considered a metric of elevated housing instability) was also associated with a threefold increase in odds of MRSA nasal colonization (OR 3.1; p = 0.01; 95% CI 1.3, 7.6). MRSA nasal colonization was strongly associated with use of public showers (OR 13.7; p = 0.02; 95% CI 1.4, 132.8), although few people in this study (4 of 78) reported using these public facilities. Sharing bedding with other people was also associated with increased risk of MRSA colonization (OR 2.2; p = 0.05; 95% CI 1.0-4.7). No associations between hand hygiene, frequency of bathing or clothes laundering, or street sleeping were observed. Use of public facilities supporting persons experiencing homelessness and housing instability, including shelters and public showers, is associated with an increased risk of MRSA nasal colonization in this study. Personal hygiene behaviors appear less associated with MRSA nasal colonization. Environmental assessments of MRSA contamination in homeless shelters and public sanitation facilities are warranted so as to inform appropriate intervention activities.

Topics: Adult; Boston; Female; Humans; Hygiene; Ill-Housed Persons; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Substance Abuse, Intravenous

Healthcare personnel (HCP) acquire antibiotic-resistant bacteria on their gloves and gowns when caring for intensive care unit (ICU) patients. Yet, contact precautions for patients with methicillin-resistant Staphylococcus aureus (MRSA) remains controversial despite existing guidelines. We sought to understand which patients are more likely to transfer MRSA to HCP and to identify which HCP interactions are more likely to lead to glove or gown contamination.. This was a prospective, multicenter cohort study of cultured HCP gloves and gowns for MRSA. Samples were obtained from patients' anterior nares, perianal area, and skin of the chest and arm to assess bacterial burden.. Among 402 MRSA-colonized patients with 3982 interactions, we found that HCP gloves and gowns were contaminated with MRSA 14.3% and 5.9% of the time, respectively. Contamination of either gloves or gowns occurred in 16.2% of interactions. Contamination was highest among occupational/physical therapists (odds ratio [OR], 6.96; 95% confidence interval [CI], 3.51, 13.79), respiratory therapists (OR, 5.34; 95% CI, 3.04, 9.39), and when any HCP touched the patient (OR, 2.59; 95% CI, 1.04, 6.51). Touching the endotracheal tube (OR, 1.75; 95% CI, 1.38, 2.19), bedding (OR, 1.43; 95% CI, 1.20, 1.70), and bathing (OR, 1.32; 95% CI, 1.01, 1.75) increased the odds of contamination. We found an association between increasing bacterial burden on the patient and HCP glove or gown contamination.. Gloves and gowns are frequently contaminated with MRSA in the ICU. Hospitals may consider using fewer precautions for low-risk interactions and more for high-risk interactions and personnel.

Topics: Anal Canal; Bacterial Load; Cross Infection; Drug Resistance, Multiple, Bacterial; Equipment Contamination; Gloves, Protective; Health Personnel; Humans; Infection Control; Infectious Disease Transmission, Patient-to-Professional; Intensive Care Units; Methicillin-Resistant Staphylococcus aureus; Nose; Patients; Prospective Studies; Protective Clothing; Skin; Staphylococcal Infections

Ear, nose and throat involvement in granulomatosis with polyangiitis (GPA) is frequently the initial disease manifestation. Previous investigations have observed a higher prevalence of Staphylococcus aureus in patients with GPA, and chronic nasal carriage has been linked with an increased risk of disease relapse. In this cross-sectional study, we investigated changes in the nasal microbiota including a detailed analysis of Staphylococcus spp. by shotgun metagenomics in patients with active and inactive granulomatosis with polyangiitis (GPA). Shotgun metagenomic sequence data were also used to identify protein-encoding genes within the SEED database, and the abundance of proteins then correlated with the presence of bacterial species on an annotated heatmap.. The presence of S. aureus in the nose as assessed by culture was more frequently detected in patients with active GPA (66.7%) compared with inactive GPA (34.1%). Beta diversity analysis of nasal microbiota by bacterial 16S rRNA profiling revealed a different composition between GPA patients and healthy controls (P = 0.039). Beta diversity analysis of shotgun metagenomic sequence data for Staphylococcus spp. revealed a different composition between active GPA patients and healthy controls and disease controls (P = 0.0007 and P = 0.0023, respectively), and between healthy controls and inactive GPA patients and household controls (P = 0.0168 and P = 0.0168, respectively). Patients with active GPA had a higher abundance of S. aureus, mirroring the culture data, while healthy controls had a higher abundance of S. epidermidis. Staphylococcus pseudintermedius, generally assumed to be a pathogen of cats and dogs, showed an abundance of 13% among the Staphylococcus spp. in our cohort. During long-term follow-up of patients with inactive GPA at baseline, a higher S. aureus abundance was not associated with an increased relapse risk. Functional analyses identified ten SEED protein subsystems that differed between the groups. Most significant associations were related to chorismate synthesis and involved in the vitamin B. Our data revealed a distinct dysbiosis of the nasal microbiota in GPA patients compared with disease and healthy controls. Metagenomic sequencing demonstrated that this dysbiosis in active GPA patients is manifested by increased abundance of S. aureus and a depletion of S. epidermidis, further demonstrating the antagonist relationships between these species. SEED functional protein subsystem analysis identified an association between the unique bacterial nasal microbiota clusters seen mainly in GPA patients and an elevated abundance of genes associated with chorismate synthesis and vitamin B

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Case-Control Studies; Cohort Studies; Cross-Sectional Studies; Female; Granulomatosis with Polyangiitis; Humans; Male; Metagenome; Microbiota; Middle Aged; Nose; Pilot Projects; Staphylococcal Infections; Staphylococcus; Young Adult

In 2016, very high rates of methicillin-resistant Staphylococcus aureus (MRSA)-ST398 (99%) were found in Portuguese pig farms that used colistin, amoxicillin, and zinc oxide as feed additives. Since then, farms A and B banned the use of colistin, and farm C banned the use of both antibiotics.. The aim of the present study was to evaluate the impact of the ban of colistin and amoxicillin on pig MRSA carriage rates, clonal types and antimicrobial resistance, compared to the results obtained in 2016.. In 2018, 103 pigs (52 from farm B using amoxicillin only as a feed additive and 51 from farm C where no antibiotics were included in the feed regimen) were nasally swabbed for MRSA colonization. Isolates were tested for antimicrobial susceptibility, and characterised by spa typing, SCCmec typing and MLST. Whole genome sequencing (WGS) was performed for representative isolates.. Overall, 96% of the pigs swabbed in 2018 carried MRSA, mostly ST398-SCCmec V-spa types t011/t108. MRSA from pigs not receiving antibiotics in the feed regimen showed susceptibility to a higher number of antibiotics, namely erythromycin, ciprofloxacin, gentamicin, and chloramphenicol. Notably, most of these isolates (n = 52) presented an unusual erythromycin-susceptibility/clindamycin-resistance phenotype. WGS showed that these isolates lacked the erm and the lnu genes encoding resistance to macrolides and lincosamides, respectively, but carried the vgaALC gene encoding resistance to lincosamides, which is here firstly identified in S. aureus ST398.. After two years the ban of colistin and amoxicillin as feed additives had no significant impact on the MRSA nasal carriage rates. Nevertheless, the MRSA strains circulating in those farms showed resistance to a lower number of antibiotic classes.

Topics: Amoxicillin; Animal Feed; Animals; Anti-Bacterial Agents; Carrier State; Colistin; Drug Resistance, Multiple, Bacterial; Farms; Methicillin-Resistant Staphylococcus aureus; Nose; Portugal; Staphylococcal Infections; Swine; Swine Diseases; Whole Genome Sequencing

Staphylococcus aureus carriage is a known risk factor for staphylococcal disease. However, the carriage rates vary by country, demographic group and profession. This study aimed to determine the S. aureus carriage rate in children in Eastern Uganda, and identify S. aureus lineages that cause infection in Uganda.. Nasopharyngeal samples from 742 healthy children less than 5 years residing in the Iganga/Mayuge Health and Demographic Surveillance Site in Eastern Uganda were processed for isolation of S. aureus. Antibiotic susceptibility testing based on minimum inhibitory concentrations (MICs) was determined by the BD Phoenix™ system. Genotyping was performed by spa and SCCmec typing.. The processed samples yielded 144 S. aureus isolates (one per child) therefore, the S. aureus carriage rate in children was 19.4% (144/742). Thirty one percent (45/144) of the isolates were methicillin resistant (MRSA) yielding a carriage rate of 6.1% (45/742). All isolates were susceptible to rifampicin, vancomycin and linezolid. Moreover, all MRSA were susceptible to vancomycin, linezolid and clindamycin. Compared to methicillin susceptible S. aureus (MSSA) isolates (68.8%, 99/144), MRSA isolates were more resistant to non-beta-lactam antimicrobials -trimethoprim/sulfamethoxazole 73.3% (33/45) vs. 27.3% (27/99) [p < 0.0001]; erythromycin 75.6% (34/45) vs. 24.2% (24/99) [p < 0.0001]; chloramphenicol 60% (27/45) vs. 19.2% (19/99) [p < 0.0001]; gentamicin 55.6% (25/45) vs. 25.3% (25/99) [p = 0.0004]; and ciprofloxacin 35.6% (16/45) vs. 2% (2/99) [p < 0.0001]. Furthermore, 42 MRSA (93.3%) were multidrug resistant (MDR) and one exhibited high-level resistance to mupirocin. Overall, 61 MSSA (61.6%) were MDR, including three mupirocin and clindamycin resistant isolates. Seven spa types were detected among MRSA, of which t037 and t064 were predominant and associated with SCCmec types I and IV, respectively. Fourteen spa types were detected in MSSA which consisted mainly of t645 and t4353.. S. aureus carriage rate in healthy children in Eastern Uganda is high and comparable to rates for hospitalized patients in Kampala. The detection of mupirocin resistance is worrying as it could rapidly increase if mupirocin is administered in a low-income setting. S. aureus strains of spa types t064, t037 (MRSA) and t645, t4353 (MSSA) are prevalent and could be responsible for majority of staphylococcal infections in Uganda.

Topics: Anti-Bacterial Agents; Antigens, Bacterial; Carrier State; Child, Preschool; Cross-Sectional Studies; Drug Resistance, Bacterial; Female; Genotyping Techniques; Humans; Infant; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Typing; Mupirocin; Nasal Mucosa; Nose; Pharynx; Population Surveillance; Staphylococcal Infections; Staphylococcus aureus; Uganda

We have noticed that patients colonized with methicillin-susceptible Staphylococcus aureus (MSSA) rarely get methicillin-resistant S. aureus (MRSA) infections. The purpose of this study was to compare the odds of a Staphylococcus aureus (SA) infection being an MRSA infection in MSSA carriers, MRSA carriers and non-carriers of SA.. Hospitalizations of adult patients at the Cleveland Clinic Health System from 2008 to 2015 were screened to identify those where the patient was tested for SA colonization. The first such hospitalization was identified. Among these 90 891 patients, those who had an SA infection during the hospitalization were included. SA carrier status (MRSA, MSSA, or non-carrier), was defined based on the first nasal SA test result. The association of carrier status and MRSA infection was examined.. The mean (±standard deviation (SD)) age of the 1999 included patients was 61 (17) years, and 1160 (58%) were male. Thirty percent, 26%, and 44%, were MRSA carriers, MSSA carriers and non-carriers, respectively. Of the 601 SA infections in MRSA carriers (reference group), 552 (92%) were MRSA infections compared with 42 (8%) of 516 in MSSA carriers (odds ratio (OR) 0.008, 95% confidence interval (CI) 0.005-0.012, p <0.0001) and 430 (49%) of 882 in non-carriers (OR 0.072, 95% CI 0.051-0.100, p <0.0001), after controlling for age, sex, hospital length of stay and calendar year.. Among patients with SA infection, the odds of the infection being an MRSA infection are 125-times lower in an MSSA carrier than in an MRSA carrier.

Topics: Adult; Aged; Carrier State; Cross Infection; Female; Hospitalization; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nasal Cavity; Nose; Odds Ratio; Ohio; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus frequently causes infections in outpatient and hospital settings and can present as a highly variable entity. Typical manifestations are endocarditis, osteoarticular infections or infection of implanted prostheses, intravascular devices or foreign bodies. A thorough diagnostic evaluation with early focus identification is mandatory to improve patient outcome.. We report a case of a 68-year old patient with a history of double allogeneic stem cell transplant for acute myeloid leukemia who developed a S. aureus bacteremia with dissemination, severe sepsis and lethal outcome due to nasal handkerchief packing after nose bleeding.. A thorough medical examination with further diagnostic work-up is most important in S. aureus blood stream infection to identify and eradicate the portal(s) of entry, to rule out endocarditis, to search for spinal abscesses, osteomyelitis or spondylodiscitis. Adherence to management guides for clinicians must be of major importance to achieve optimal quality of clinical care, and thus improve patient outcome.

Topics: Aged; Bacteremia; Cross Infection; Diagnosis, Differential; Fatal Outcome; Germany; Humans; Leukemia, Myeloid, Acute; Male; Nose; Staphylococcal Infections; Staphylococcus aureus; Stem Cell Transplantation; Transplantation, Homologous

To compare mucosal flora in HIV-positive and HIV-negative subjects, to assess chemosusceptibility patterns of carriage isolates and to evaluate possible predisposing factors within the two groups.. We analyzed microbes isolated from nasopharyngeal swabs in virologically suppressed and immunologically stable HIV-positive adult outpatients (n=105) at baseline and after 12 months and in an age-matched cohort of HIV-negative outpatients (n=100) at baseline. Bacteria and Candida spp strains were isolated and identified through standard biochemical assays and chemosusceptibility tests were performed. Multi Locus Sequence Typing was also determined to characterize Staphylococcus aureus isolates from HIV-infected persistent carriers.. In HIV-positive patients a significantly higher rate of colonization by S. aureus as compared to HIV-negative controls was observed (19% vs 8%, p=0.02), with a relevant percentage of penicillin resistant strains (15% vs 0, p=0.24). Methicillin resistant strains were recovered only from HIV-positive subjects. Overall HIV-positive status was the only predictor of S. aureus colonization (OR 2.77, 95% CI 1.03;7.41, p=0.04).. The nasopharyngeal bacterial flora differs between HIV-positive and HIV-negative subjects and appears relevant for possible development of staphylococcal infections in HIV-positive patients.

Topics: Adult; Anti-Bacterial Agents; Bacteria; Bacterial Physiological Phenomena; Candida; Carrier State; HIV; HIV Infections; Humans; Multilocus Sequence Typing; Nose; Staphylococcal Infections

In Denmark, eradication treatment is recommended for methicillin-resistant Staphylococcus aureus (MRSA) carriers. Here, we analyze factors associated with eradication outcome. MRSA carriers referred to the MRSA Knowledge Center at Hvidovre Hospital in 2013 were included. Carriers were sampled from nose, throat, and perineum. Eradication regimen was 5 days of mupirocin nasal ointment and chlorhexidine whole-body wash. Oral antibiotics were sometimes added. Factors associated with eradication after the first eradication attempt were analyzed by logistic regression and expressed as odds ratio (OR) with 95% confidence interval (95% CI). Of 164 individuals, 143 completed 1- and 6-month follow-up after 1st treatment. Eradication was achieved in 63 (38.4%) patients after one treatment and 101 (61.6%) individuals became MRSA free after up to 4 eradication treatments. Throat carriage was associated with a higher failure rate (OR 0.29 (0.10-0.80)), while the presence of Panton-Valentine leukocidin (PVL) genes (37%) was associated with higher success rate (OR 3.52 (1.44-8.57)). Other factors analyzed were not significantly associated with eradication outcome. None of the 26 patients lost to follow-up developed later MRSA infections. This study estimates the efficacy of treatment of MRSA carriage with an eradication rate of 38.4% after the first treatment and a total eradication rate of 61.6% after several treatments. Throat carriers had a lower eradication success rate. Adding oral antibiotics to the first treatment did not increase success. The finding of a significant higher success rate when having a PVL-positive clone should be further investigated.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacterial Toxins; Carrier State; Child; Child, Preschool; Denmark; Exotoxins; Female; Humans; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Perineum; Pharynx; Retrospective Studies; Staphylococcal Infections; Treatment Outcome; Whole Genome Sequencing; Young Adult

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a considerable public health concern in both developed and developing countries due to the rapid spread of this bacterium around the world, also the epidemiology of MRSA has changed, as the isolation of MRSA strains is not limited to health-care settings or patients with predisposing risk factors. Therefore, the objective of this study is to determine the genetic diversity and antibiotic resistance profile of CA-MRSA nasal carriage in Iranian children.. A cross-sectional study was conducted from April 2013 to March 2014. A total of 25 CA-MRSA were isolated from the anterior nares of 410 preschool children with no risk factors. All MRSA isolates were characterized by detection of the Panton-Valentine leukocidin (pvl) and γ-hemolysin genes, staphylococcal cassette chromosome mec (SCCmec) typing and multi-locus sequence typing (MLST).. In 25 CA-MRSA isolates, Pvl and γ-hemolysin genes were detected in one (4%) and 18 (72 %) isolates; respectively. Overall, 92% (23/25) of isolates belonged to SCCmec type IV and 8% (2/25) of them had SCCmec type V profile. Using MLST, the 25 isolates were grouped into six clonal complexes (CC) and eight sequence types (ST) (CC5/ST6, CC22/ST22 and ST217, CC30/ST30 and ST1107, CC78/ST859, CC398/ST291 and CC97/ST405). The ST859/SCCmec IV (11/25, 44%) was the predominant clone among the isolates. ST859-MRSA-IV-pvl-negative (resistant to tetracycline) have successfully adapted to the Iranian preschool children population.. Our results suggest that the genomic diversity was observed among the CA-MRSA. In addition, the current study demonstrates that pvl is not a reliable marker for CA-MRSA in our region.

Topics: Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cross-Sectional Studies; DNA, Bacterial; Exotoxins; Female; Genetic Variation; Genotype; Healthy Volunteers; Hemolysin Proteins; Humans; Iran; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Risk Factors; Staphylococcal Infections; Virulence Factors

Topics: Adult; Asthma; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Current guidelines recommend adding vancomycin to empiric treatment of FN in patients who meet specific criteria. After 48 hours, the guidelines recommend discontinuing vancomycin if resistant Gram-positive organisms are not identified. Based on these recommendations, a vancomycin stewardship team defined criteria for discontinuation of vancomycin at 48 hours and increased surveillance of vancomycin usage through a multimodal approach. The purpose of this retrospective analysis is to assess the impact of this multimodal approach on the discontinuation of empiric vancomycin at 48 hours in FN.. This retrospective analysis included a pre- and post-intervention cohort of 200 HSCT recipients with FN from 2015 to 2018. Criteria for continued vancomycin use beyond 48 hours included culture-documented resistant Gram-positive infection, positive Methicillin-Resistant S aureus (MRSA) nasal swab with evidence of pneumonia, or hemodynamic instability with concern for sepsis. The following patient characteristics were collected: previous MRSA infection, MRSA nasal swab collection and results, culture results, duration of vancomycin use, rationale for continuation of vancomycin beyond 48 hours, and re-initiation of vancomycin.. In the post-intervention cohort, vancomycin discontinuation at 48 hours increased from 31% (95% CI 21.94-40.05) to 70% (95% CI 61.02-78.97; P < 0.0001). An additional 23% of vancomycin orders were discontinued at 72 hours. Off criteria vancomycin use decreased from 33% in pre to 1% in the post-implementation cohort.. Establishing define criteria for vancomycin use in FN patients with a multimodal approach of physicians from hematology and infectious diseases, clinical pharmacists and the antibiotic stewardship team significantly improved vancomycin discontinuation.

Topics: Adult; Aged; Anti-Bacterial Agents; Antimicrobial Stewardship; Febrile Neutropenia; Female; Hematopoietic Stem Cell Transplantation; Humans; Male; Medication Therapy Management; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Retrospective Studies; Staphylococcal Infections; Time Factors; Vancomycin; Young Adult

Colonization by livestock-associated MRSA (LA-MRSA) has increasingly been reported in the swine population worldwide. The aim of this study was to assess the prevalence of MRSA nasal carriage in healthy pigs, including the black (Calabrese) breed, from farms in the Calabria Region (Southern Italy). Between January and March 2018, a total of 475 healthy pigs reared in 32 farms were sampled by nasal swabbing. MRSA isolates were characterized by spa, MLST and SCCmec typing, and susceptibility testing to 17 antimicrobials.. 22 of 32 (66.8%) pig farms resulted positive for MRSA. The prevalence of MRSA was 46.1% (219 MRSA culture-positive out of 475 samples). MRSA colonization was significantly higher in intensive farms and in pigs with a recent or ongoing antimicrobial treatment. All 219 MRSA isolates were assigned to ST398. The most common spa types were t011 (37.0%), t034 (22.4%) and t899 (15.1%). A novel spa type (t18290) was detected in one isolate. An insertion of IS256 in the ST398-specific A07 fragment of the SAPIG2195 gene was detected in 10 out of 81 t011 isolates. Nearly all isolates carried the SCCmec type V element, except 11 isolates that carried the SCCmec type IVc. None of the isolates was positive for the Panton-Valentine leukocidin. All isolates were resistant to tetracycline. High resistance rates were also found for clindamycin (93.1%), trimethoprim/sulfamethoxazole (68.4%), fluoroquinolones (47.9-65.3%) and erythromycin (46.1%). None of the isolates was resistant to vancomycin and fusidic acid. Overall, a multidrug resistant phenotype was observed in 88.6% of isolates.. We report a high prevalence of MRSA among healthy swine in Southern Italy farms, with higher isolation frequency associated with intensive farming. The epidemiological types identified in our study reflect those reported in other European countries. Our findings underscore the importance of monitoring the evolution of LA-MRSA in pig farms in order to implement control measures and reduce the risk of spread in the animal population.

Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; Cross-Sectional Studies; DNA, Bacterial; Drug Resistance, Bacterial; Farms; Italy; Livestock; Methicillin; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Prevalence; Staphylococcal Infections; Swine; Swine Diseases; Tetracycline

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many hospital-associated infections. Both MRSA-colonized and MRSA-infected patients must be isolated on contact precautions per the Centers for Disease Control and Prevention guidelines. This study evaluates the current practice for removing MRSA-colonized patients from contact precautions and proposes a new protocol to decrease inconsistencies with screening methodologies.. This was a retrospective chart review of MRSA screening swabs collected at an academic medical center between January 1, 2010 and December 31, 2017. Of those patients with MRSA screening swabs, extra-nasal cultures were also evaluated for MRSA infection. Screening swabs were analyzed for appropriateness of order and timing between swabs and active infections. Analysis of variance and the χ² tests were used to determine significance between groups.. This study included 8,310 patients with a combined total of 11,601 nasal swabs. Significantly more (P = .0159) patients with 2 negative nasal swabs returned with a recurrent MRSA infection or colonization than those who had 3 consecutive negative nasal swabs (27.8% vs 17.0%, respectively). Additionally, 47.8% of patients only had 1 appropriately ordered negative nasal swab, indicating that a nurse-driven protocol may be more effective in obtaining the full series of samples required to remove contact precautions.. The current practice for removing a patient from contact precautions for MRSA is insufficient. The number of negative nasal swabs required should be increased from 2 to 3 and a decolonization protocol should be implemented.

Topics: Academic Medical Centers; Adult; Aged; Anti-Bacterial Agents; Carrier State; Cross Infection; Female; Humans; Male; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Retrospective Studies; Staphylococcal Infections

Preoperative colonization with Staphylococcus aureus (SA) increases risk of surgical site infection. Screening for SA followed by skin and nasal decolonization can help to reduce the risk of postoperative infections. Risk factors for colonization are, however, not completely understood.. A case-control study using questionnaires and patient demographics specifically designed to observe SA colonization risk factors in a presurgical orthopedic population. A total of 115 subjects with a positive preoperative screen for SA nasal colonization prior to orthopedic surgery completed a questionnaire to assess for SA risk factors: these subjects served as our cases. An additional 476 controls completed similar questionnaires. Data collected included demographic, health, and lifestyle information. Multivariable logistic regression was used to generate odds ratios (OR) for risk of SA colonization.. Several risk factors were identified. Male sex (OR 2.3; 95% confidence interval [CI], [1.4-3.8]) and diabetes (OR 3.8 [1.8-7.8]) significantly increased the risk of SA colonization. Older age, visiting public places (OR 0.2 [0.1-0.3]), recent antibiotic use (OR 0.2 [0.1-0.6]), and the presence of facial hair (OR 0.3 [0.1-0.6]) significantly lowered the risk of SA colonization.. By identifying patients who may be at greater risk of SA colonization, we can better streamline our presurgical techniques to help reduce risk of surgical site infections and improve patient outcomes.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Case-Control Studies; Child; Diabetes Mellitus; Female; Humans; Male; Middle Aged; Mupirocin; Nose; Orthopedic Procedures; Preoperative Care; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Young Adult

For patients with possible Staphylococcus aureus infection, providers must decide whether to treat empirically for methicillin-resistant S. aureus (MRSA). Nares MRSA colonization screening tests could inform decisions regarding empiric MRSA-active antibiotic use.1,2.

Topics: Anti-Bacterial Agents; Hospitals, Veterans; Humans; Methicillin-Resistant Staphylococcus aureus; Minnesota; Nose; Retrospective Studies; Staphylococcal Infections; Veterans

Staphylococcal infections can cause significant morbidity in patients undergoing dialysis. This study evaluated the effects of HIV infection on nasal carriage of Staphylococcus aureus, staphylococcal peritonitis, and catheter infection rates in patients with end-stage renal failure managed with continuous ambulatory peritoneal dialysis (CAPD).. Sixty HIV-positive and 59 HIV-negative CAPD patients were enrolled and followed up for up to 18 months. S. aureus nasal carriage (detected by nasal swab culture), Staphylococcal peritonitis (diagnosed by clinical presentation, and CAPD effluent Staphylococcal culture and white blood cell count ≥100 cells/µL), and catheter infections (including exit site and tunnel infections) were assessed monthly.. At 18 months, S. aureus nasal carriage rates were 43.3% and 30.5% (p = 0.147) and the methicillin-resistant S. aureus (MRSA) nasal carriage rates were 31.7% and 13.6% (p = 0.018) for the HIV-positive and HIV-negative cohorts, respectively. The HIV-positive cohort was associated with increased hazards for staphylococcal peritonitis, (adjusted hazard ratio [AHR] 2.85, 95% confidence interval [CI] 1.19-6.84, p = 0.019) due to increased coagulase-negative staphylococcal (CNS) peritonitis rate in the HIV-positive cohort compared with the HIV-negative cohort (0.435 vs. 0.089 episodes/person-years; AHR 7.64, CI 2.18-26.82, p = 0.001). On multivariable analysis, CD4+ cell count <200 cells/µL, diabetes, and S. aureus nasal carriage were found to be independent predictors of S. aureus peritonitis.. These findings suggest that HIV infection may be a risk factor for MRSA nasal colonization and may increase the risks of CNS peritonitis, while a CD4+ cell count <200 cells/µL and S. aureus nasal carriage may be important predictors of S. aureus peritonitis.

Topics: Adult; Carrier State; Catheter-Related Infections; Catheters, Indwelling; Female; Follow-Up Studies; HIV Infections; Humans; Kidney Failure, Chronic; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Prospective Studies; Risk Factors; Staphylococcal Infections

Dialysis patients are frequently exposed to Staphylococcus aureus due to stays in dialysis centers, hospitals or rest homes. The hemodialysis vascular access is a potential entry site for S. aureus, in particular when using a central venous catheter (CVC) which increases the risk of sepsis compared to arteriovenous (AV) fistula. We prospectively followed a cohort of 86 hemodialysis patients from an outpatient dialysis center over 25 months analyzing S. aureus carrier status, S. aureus infection rates and mortality.. Demographic data and patients´ medical histories were collected and followed from all hemodialysis patients. Blood samples, nasal swabs and swabs from the hemodialysis vascular access site were taken every six months for a period of 25 months and tested for S. aureus. Strains were cultured and further characterized by spa PCR and microarray-based genotyping. Resulting data were compared with those from the general population.. In cross-sectional analyses, an average of 40% of hemodialysis patients were S. aureus carriers compared to 27% in the general population. Longitudinally, a total of 65% were S. aureus carriers: 16% were persistent carriers, 43% were intermittently colonized. The most common S. aureus lineage in the dialysis patient cohort was the clonal complex (CC) 8 and the spa type t008, while in the general population, the clonal complex CC30 dominates. During the study period, we observed six S. aureus-associated blood stream infections with one S. aureus attributable death. S. aureus carriers with an AV fistula were more densely colonized in the nasal mucosa compared to patients with a CVC. Overall mortality was lower for hemodialysis patients with a positive S. aureus carrier status compared to non-carriers (hazard ratio of 0.19).. Compared to the general population, hemodialysis patients were more frequently colonized with S. aureus and displayed both different S. aureus colonization densities as well as lineages, possibly explained by more frequent exposure to health care environments. The lower overall mortality in carriers compared to non-carriers is intriguing and will be investigated in detail in the future.. ISRCTN 14385893 , 2. October 2018, retrospectively registered.

Topics: Adult; Aged; Aged, 80 and over; Arteriovenous Shunt, Surgical; Bacteremia; Carrier State; Catheter-Related Infections; Cause of Death; Central Venous Catheters; Cross Infection; Cross-Sectional Studies; Female; Follow-Up Studies; Germany; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prospective Studies; Renal Dialysis; Staphylococcal Infections; Time Factors; Young Adult

This work was focused to determine the prevalence and the species diversity of coagulase-negative staphylococci (CoNS) in wild boars, and to study their antimicrobial resistance phenotype and genotype. Nasal samples of 371 wild boars from six Spanish regions were collected for CoNS recovery. The identification was performed by MALDI-TOF mass-spectrometry. Antimicrobial susceptibility for eight antimicrobial agents was studied by disc-diffusion method and the presence of 31 antimicrobial resistance genes by PCR. CoNS were detected in nasal samples of 136/371 animals tested (36.6%), and 161 isolates were obtained (1-3/animal); a high diversity of species was found (n = 17), with predominance of S. sciuri (n = 64), S. xylosus (n = 21) and S. chromogenes (n = 17). Among CoNS isolates, 22.4% showed resistance to at least one antimicrobial tested. Tetracycline-resistance phenotype was the most frequently detected (10.5%), generally mediated by tet(K) gene [associated or not with tet(L)]. Other relevant resistance genes were identified including unusual ones [mecA, erm(B), erm(F), mphC, erm(43), msr(A)/msr(B), lnu(A), dfrG, fexA, and cat

Topics: Animals; Anti-Bacterial Agents; Coagulase; Drug Resistance, Bacterial; Genes, Bacterial; Genetic Variation; Microbial Sensitivity Tests; Nose; Phenotype; Spain; Staphylococcal Infections; Staphylococcus; Sus scrofa; Swine; Swine Diseases

This work aimed to determine the prevalence, diversity, antibiotic-resistance phenotype/genotype and virulence factors in staphylococci of farm-animals. Nasal samples of 117 farm-animals (calve: 72; lamb: 37; goat: 8) were collected from one slaughterhouse in La Rioja/Spain and cultured for staphylococci and methicillin-resistant Staphylococcus (MRS) recovery. Identification was performed by MALDI-TOF. Antimicrobial resistance phenotype/genotype was determined by susceptibility testing and specific PCRs. Molecular typing (spa-typing, multilocus-sequence-typing, agr-typing, SCCmec), and detection of 12 virulence genes and human Immune-evasive-cluster (IEC) genes were performed by PCR/sequencing in S. aureus. Two marker genes of arginine catabolic mobile element (ACME) were determined by PCR (USA300-MRSA detection). Staphylococci were identified in 50%, 54% and 21% of goat, lamb and calve samples, respectively. Among the 13 S. aureus isolates recovered, 11 were susceptible to all antimicrobials tested, and two were multidrug-resistant-MRSA [beta-lactams (blaZ, mecA), macrolides [(msr(A)/msr(B)] and fluoroquinolones]. The MSSA harboured either tst or enterotoxin genes, while the MRSA harboured the lukF/lukS-PV genes. Five sequence-types were detected. The two MRSA strains (from lamb and goat) were typed as t5173/ST8/agr-I/SCCmec-IVa/ACME-positive, corresponding to USA300 clone, and were IEC-B-positive. Among the 47 coagulase-negative staphylococci (CoNS), six species were identified, predominating S. simulans (n = 25) and S. sciuri (n = 11). Fifty-three percent of CoNS showed resistance to at least one antimicrobial agent (six multidrug-resistant strains), and the following resistance phenotypes/genotypes were detected: streptomycin [27.6%; ant(6)-Ia, str], tetracycline [23.4%; tet(M), tet(L), tet(K)], clindamycin [19.1%; lnu(A), vgaA], erythromycin [10.6%; erm(C), msr(A)/msr(B)], chloramphenicol (8.5%; fexA), tobramycin (6.4%), penicillin-cefoxitin (4.3%; blaZ, mecA), and SXT (2.1%). The detection of the MRSA-USA300 lineage in food animals is worrisome and should be further monitored.

Topics: Animals; Anti-Bacterial Agents; Carrier State; Disease Reservoirs; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Genetic Variation; Genotype; Goats; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Polymerase Chain Reaction; Prevalence; Red Meat; Sheep; Spain; Staphylococcal Infections; Staphylococcus; Tetracycline; Virulence Factors

Methicillin-resistant

Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Biofilms; Carrier State; Cross-Sectional Studies; Drug Resistance, Microbial; Drug Resistance, Multiple, Bacterial; Ethiopia; Female; HIV Infections; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Staphylococcal Infections; Young Adult

The information available on antibiotic resistance patterns are generally based on specimens from hospitalised individuals. This study was aimed at evaluating the antibiotic resistance rate of nasal carriage strains of Staphylococcus aureus and Streptococcus pneumoniae in healthy individuals, in accordance with age and gender, attended in Primary Care Centres (PCC).. Cross-sectional study.. Seven PCC in the Barcelona area.. Healthy nasal carriers aged 4years or more who did not present with any sign of infectious disease, and had not taken any antibiotic or had been hospitalised in the previous 3months.. A total of 3,969 nasal swabs valid for identification were collected between 2010 and 2011 and were sent to one central microbiological laboratory for isolation of both pathogens. Resistance to common antibiotics was determined on the basis of the current European Committee on Antimicrobial Susceptibility Testing guidelines on cut-off points.. The prevalence of methicillin-resistant S.aureus was 1.3% (95%CI: 0.5-2.1%), with resistance rates of 87.1% to phenoxymethylpenicillin and 11.6% to azithromycin, with no significant differences with age and gender. A total of 2.4% (95CI%: 0.1-4.7%) of the pneumococcal strains were highly resistant to both phenoxymethylpenicillin and macrolides, whereas the highest resistance rates were to cefaclor (53.3%), followed by tetracycline (20%) and cefuroxime (12.1%).. These pathogens have lower resistance rates in the community than in the hospital setting. Primary Care physicians must be more aware of the current antimicrobial resistance, in order to ensure prudent use of antibiotics.

Topics: Adolescent; Adult; Age Factors; Aged; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Cross-Sectional Studies; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Nose; Pneumococcal Infections; Primary Health Care; Sex Factors; Spain; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae; Urban Health; Young Adult

Success of methicillin-resistant Staphylococcus aureus (MRSA) decolonization procedures is usually verified by control swabs of the colonized body region. This prospective controlled study compared a single-day regimen with a well-established 3-day scheme for noninferiority and adherence to the testing scheme.. Two sampling schemes for screening MRSA patients of a single study cohort at a German tertiary-care hospital 2 days after decolonization were compared regarding their ability to identify MRSA colonization in throat or nose. In each patient, three nose and three throat swabs were taken at 3- to 4-hour intervals during screening day 1, and in the same patients once daily on days 1, 2 and 3. Swabs were analysed using chromogenic agar and broth enrichment. The study aimed to investigate whether the single-day swabbing scheme is not inferior to the 3-day scheme with a 15% noninferiority margin.. One hundred sixty patients were included, comprising 105 and 101 patients with results on all three swabs for decolonization screening of the nose and throat, respectively. Noninferiority of the single-day swabbing scheme was confirmed for both pharyngeal and nasal swabs, with 91.8% and 89% agreement, respectively. The absolute difference of positivity rates between the swabbing regimens was 0.025 (-0.082, 0.131) for the nose and 0.006 (-0.102, 0.114) (95% confidence interval) for the pharynx as calculated with McNemar's test for matched or paired data. Compliance with the single-day scheme was better, with 12% lacking second-day swabs and 27% lacking third-day swabs from the nostrils.. The better adherence to the single-day screening scheme with noninferiority suggests its implementation as the new gold standard.

Topics: Carrier State; Disinfection; Female; Humans; Infection Control; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Pharynx; Staphylococcal Infections

Methicillin-resistant staphylococci (MRS), namely Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), are opportunistic agents of great importance in human and veterinary medicine. The aims of this study were to investigate the frequency, persistence, and risk factors associated with nasal colonization by MRS in people in daily contact with animals in Portugal. Seventy-nine out of 129 (61.2%) participants were found to be colonized by, at least, one methicillin-resistant (MR) staphylococci species (MR Staphylococcus epidermidis [n = 68], MRSA [n = 19], MR Staphylococcus haemolyticus [n = 7], MRSP [n = 2], and other coagulase-negative staphylococci [n = 4]). Three lineages were identified among the MRSA isolates (n = 7): the major human healthcare clone in Portugal (ST22-t032-IV, n = 3), the livestock-associated MRSA (ST398-t108-V, n = 3), and the New York-/Japan-related clone (ST105-t002-II, n = 1). MRSP isolates belonged to the European clone ST71-II-III. We identified two risk factors for nasal colonization by MRS in healthy humans: (i) being a veterinary professional (veterinarian and veterinary nurse) (p < 0.0001, odds ratio [OR] = 6.369, 95% confidence interval [CI, 2.683-15.122]) and (ii) have contacted with one MRSA- or MRSP-positive animal (p = 0.0361, OR = 2.742, 95% CI [1.067-7.045]). The follow-up study revealed that the majority (85%) remain colonized. This study shows that MRS in veterinary clinical practice is a professional hazard and highlights the need to implement preventive measures to minimize spread.

Topics: Animals; Anti-Bacterial Agents; Carrier State; Female; Follow-Up Studies; Humans; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Nasal Cavity; Nose; Pets; Portugal; Risk Factors; Staphylococcal Infections; Veterinarians

The costs and laboratory workload arising from meticillin-resistant Staphylococcus aureus (MRSA) screening could be reduced markedly by processing nose, throat and skin swabs from one person in a single culture broth (specimen pooling). The purpose of this study was to evaluate the sensitivities and times for MRSA detection using a variety of approaches to processing of individual and pooled swabs.. Four hundred and seventeen swabs from 139 subjects with a history of MRSA colonization (three swabs per subject - nose, throat and skin) were submitted. Swabs were suspended in 200-μL sterile saline, and these suspensions were used individually and as pooled samples to inoculate two different chromogenic media [MRSA SMART (bioMėrieux, Marcy-l'Étoile, Paris, France) and CHROMagar MRSA (CHROMagar, Paris, France)] and Todd-Hewitt Broth; the latter cultures were then subcultured on to the same chromogenic media.. MRSA was detected from at least one specimen in 75 subjects (50.4%). The diagnostic sensitivities of pooled surveillance cultures compared with single cultures were 97% and 93% for direct and enrichment cultures, respectively. Enrichment culture of either individual or pooled samples had no benefit compared with direct culture (P>0.05).. Pooling of MRSA screening swabs for either direct culture on chromogenic agar or enrichment culture is suitable for routine use.

Topics: Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Carrier State; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Sensitivity and Specificity; Skin; Specimen Handling; Staphylococcal Infections; Time Factors

Asymptomatic carriage of Staphylococcus aureus is a source of transmission between healthy individuals. Seventy children at a primary school were swabbed 7 times to identify patterns of S. aureus carriage. S. aureus carriage prevalence was 53%-65% at each round and 45% carried at every round. High carriage prevalence may indicate that school-aged children are important contributors to S. aureus transmission.

Topics: Anti-Bacterial Agents; Carrier State; Child; Cohort Studies; Female; Humans; Male; New Zealand; Nose; Prevalence; Schools; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires

Staphylococcus aureus colonization leading to skin and soft-tissue infections (SSTI) are known challenges in crowded settings such as the military. The aim of the study was to establish and compare the prevalence of S. aureus colonization in recruits at enrolment and discharge after the first year of military service, and to investigate the prevalence of S. aureus SSTI.. All recruits entering first year of military service in January 2013 to be stationed at three garrisons in the northern part of Norway were invited to join this prospective cohort study. Swabs were taken from nose, throat and perineum. Staphylococcus aureus was identified using standard culturing methods. Methicillin resistance was determined by a cefoxitin disc diffusion test.. Of the 923 eligible recruits, 512 were included at enrolment; 265/512 (52%) were also screened at discharge. Staphylococcus aureus colonization was high, and increased significantly during military service (166/265 versus 224/265, p < 0.001) mainly caused by increase in throat colonization alone or in combination with nasal colonization. All S. aureus isolates were susceptible to methicillin. SSTI was self-reported in 7/265 (3%) recruits, of which only one was confirmed by a military physician.. Staphylococcus aureus colonization increased during military service, but there were few confirmed reports of SSTI. Inclusion of throat swab provides important information as ∼20% of the recruits were only positive in their throat. Further analyses need to be performed to investigate if the increase in colonization is caused by specific S. aureus stains.

Topics: Carrier State; Female; Humans; Male; Methicillin; Microbial Sensitivity Tests; Military Personnel; Norway; Nose; Perineum; Prevalence; Prospective Studies; Skin; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Resistant and virulent Staphylococcus aureus is a global public health challenge. Staphylococcal Bi-component leukotoxins are cytolytic to immune cells and evolve to disarm the innate immunity during infections, hence the severity of the disease.. We studied drug resistance profile and the occurrence of bi-component leukocidin in clinical and nasal S. aureus in Lagos, Nigeria.. Ninety-two S. aureus (70 clinical and 22 nasal) strains were characterized by conventional and molecular methods.. Of the resistance profiles generated, no isolate was resistant to fosfomycin, fusidic acid, teicoplanin, vancomycin, linezolid, mupirocin, nitrofurantoin and tigecycline. Twelve MRSA carrying staphylococcal cassette chromosome mecA gene types I, III, and IV elements were identified only in the clinical samples and type I dominated. High rates of lukE/D (100% among MRSA) and lukPV (dominated MSSA) were recorded among the nasal and clinical isolates. Staphylococcus aureus harboring only lukE/D (from clinical & colonizing MSSA) and combined lukE/D and lukPV (mostly from clinical MSSA, colonizing MSSA and clinical MRSA) toxins were found.. Although, mecA resistant genes were found only among clinical MRSA, the occurrence of other bi-component leukocidin genes in a large proportion among the isolates from both community and clinical settings is a major concern. The need for effective resistance and virulence factor surveillance, re-enforcement of antibiotic stewardship and good infection control policy, to prevent dissemination of epidemic strains is highlighted.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacterial Toxins; Cohort Studies; Drug Resistance, Bacterial; Exotoxins; Female; Hemolysin Proteins; Humans; Immunity, Innate; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Epidemiology; Molecular Typing; Nigeria; Nose; Penicillin-Binding Proteins; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

We collected nasal samples from 1,390 healthy 3-7 years old children in Szolnok city, Hungary, in 2012. We detected 476 Staphylococcus aureus isolates from 474 children. In two occasions, two different S. aureus were isolated, based on hemolysis type and pulsed-field gel electrophoresis pattern. S. aureus carriage rate was calculated to be 34.1% similar to others studies. Male gender was found to be a risk factor for carriage by statistical analysis. Altogether, four methicillin-resistant S. aureus (MRSA) strains were detected by mecA polymerase chain reaction, which means 0.8% community-acquired MRSA prevalence among the S. aureus isolates. All MRSA strains harbored the SCCmec type IV cassette (typical for CA-MRSA) and belonged to ST45 by multilocus sequence typing. During antibiotic susceptibility testing, we measured the following resistance rates: 0.0% for mupirocin, 0.2% for ciprofloxacin, 0.6% for gentamicin and oxacillin, 3.4% for tetracycline, 9.5% for clindamycin, 10.3% for erythromycin, and 91.4% for penicillin, which are generally lower compared with Hungarian clinical isolates.

Topics: Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Drug Resistance, Bacterial; Female; Humans; Hungary; Male; Microbial Sensitivity Tests; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus

Examine the relationship between colonization with Staphylococcus aureus in the community and symptomatic infection in two cohorts of Iowans.. Case series within cohort study.. Rural Iowans selected from the Keokuk Rural Health Study, the Agricultural Health Study, and the Iowa Voter Registry.. Longitudinal study within established cohorts evaluating documented S. aureus infections with samples available for molecular typing.. We examined this relationship in two cohorts of Iowans with a combined 11 incident cases of S. aureus SSTI, for which samples were available. Seven of the 11 individuals (63.6%) were colonized at baseline, in the nose (3/7, 42.9%), or in both the nose and throat (57.1%). All seven cases had matching sequence types between colonization and infection isolates.. Staphylococcus aureus causes millions of skin and soft tissue infections yearly. Although colonization with S. aureus is a frequent antecedent to infection, many studies investigating the link between colonization and infection have taken place in a clinical setting, particularly in urban hospitals. Our study has shown similar results in a rural community setting to those previously seen in clinics.

Topics: Adult; Aged; Anti-Bacterial Agents; Carrier State; Community-Acquired Infections; Female; Humans; Iowa; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Risk Factors; Rural Population; Skin; Soft Tissue Infections; Staphylococcal Infections; Staphylococcal Skin Infections

Methicillin-resistant Staphylococcus aureus (MRSA) colonization is associated with serious surgical site infection in high-risk patients. High prevalence of MRSA colonization was reported in many settings, nonetheless local data is required. The purpose of this study is to identify the prevalence and risk factor of MRSA nasal carriage in adult patients in National Referral Hospital in Indonesia before underwent elective surgical procedure.. From 384 patients, 16.9% patients of them had undergone orthopaedic surgery, 51.3% had received antibiotics within the previous 3-month and 41.1% patients had history of hospitalization within the previous 1 year. Total of 21.6% patients were on invasive devices for at least 48 h before the operation; 24.2% had an open wound; 19.3% patients were referred from other hospital/ward. Of these patients, solid tumor without metastasis was the most common factor identified by the Charlson index (38.3%). Nasal colonization of Gram-positive bacteria was detected in 76.8%; S. aureus in 15.6% of patients (n = 60). MRSA was identified in three isolates (0.8%) by both culture and polymerase chain reaction (PCR) tests. Due to low prevalence of MRSA nasal carriage, this finding supports the recommendation to not routinely apply mupirocin for nasal decolonization on patient planned for surgery in Indonesia.

Topics: Adult; Cross-Sectional Studies; Elective Surgical Procedures; Female; Humans; Indonesia; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Preoperative Period; Prevalence; Referral and Consultation; Staphylococcal Infections; Staphylococcus aureus

Several studies have shown that Staphylococcus aureus (S aureus) nasal colonization is associated with surgical site infection and that preoperative decolonization can reduce infection rates. Up to 30% of joint arthroplasty patients have positive S aureus nasal swabs. Patient risk factors for colonization remain largely unknown. The aim of this study was to determine whether there is a specific patient population at increased risk of S aureus nasal colonization.. This study is a retrospective review of 716 patients undergoing hip or knee arthroplasty beginning in 2011. All patients were screened preoperatively for nasal colonization. Univariate and multivariate analyses were used to assess risk factors for nasal colonization.. A total of 716 patients undergoing joint arthroplasty had preoperative nasal screening. One hundred twenty-five (17.50%) nasal swabs were positive for methicillin-susceptible S aureus (MSSA), 13 (1.80%) were positive for methicillin-resistant S aureus (MRSA), and 84 (11.70%) were positive for other organisms. In bivariate analysis, diabetes (P = .04), renal insufficiency (P = .03), and immunosuppression (P = .02) were predictors of nasal colonization with MSSA/MRSA. In multivariate analysis, immunosuppression (P = .04; odds ratio, 2.0; 95% confidence interval, 1.03-3.71) and renal insufficiency (P = .04; odds ratio, 2.5; 95% confidence interval, 1.01-6.18) were independent predictors of nasal colonization with MSSA/MRSA.. Overall, 17.5% of patients undergoing primary hip or knee arthroplasty screened positive for S aureus. Diabetes, renal insufficiency, and immunosuppression are risk factors for such colonization. Given that these comorbidities are already known independent risk factors for periprosthetic joint infection, these patients should be particularly screened and when necessary, decolonized.

Topics: Aged; Arthroplasty, Replacement, Knee; Cross Infection; Diagnostic Tests, Routine; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Retrospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

This study aimed to estimate the prevalence of methicillin-susceptible and -resistant. A cross-sectional study was carried out in 2016-2017 among 239 podiatrists in Spain. The presence of MSSA, MRSA, and MRSE was determined by microbiological analysis of nasal exudate and antimicrobial susceptibility was determined. Each podiatrist completed a questionnaire. The questionnaire comprised various parameters such as sex, age, podiatry experience duration, underlying diseases, prior antibiotic treatment, hospitalization during the last year, and use of a protective mask, an aspiration system, or gloves.. The prevalence of MSSA, MRSA, and MRSE was 23.0%, 1.3%, and 23.8%, respectively. The MSSA prevalence was higher among podiatrists who did not use an aspiration system (32.3%) compared to those who did (19.3%;. The prevalence of

Topics: Adult; Age Factors; Anti-Bacterial Agents; Cross-Sectional Studies; Female; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Risk Factors; Sex Factors; Spain; Staphylococcal Infections; Staphylococcus; Staphylococcus epidermidis; Surveys and Questionnaires

Dental health-care professionals (DHCPs) with nasal colonisation of methicillin-resistant Staphylococcus aureus (MRSA) can serve as a reservoir for MRSA transmission to others and be exposed to self-contamination with MRSA. Evaluating the knowledge, attitudes and actual practice of DHCPs is imperative for appropriate infection control.. Dentists, dental hygienists and dental technologists from Seoul National University Dental Hospital were recruited to participate in a cross-sectional survey and undergo nasal sampling of MRSA. The survey included demographic questions, six questions about knowledge, eight questions about attitudes/perceptions and six questions about practices/behaviours regarding MRSA infection control. Nasal samples from the participants were analysed for MRSA presence, antimicrobial susceptibility and staphylococcal cassette chromosome mec (SCCmec) typing. MRSA carriers underwent decolonisation with topical mupirocin.. Among 139 DHCPs, four (2.9%) were nasal MRSA carriers. Decolonisation was successful in three participants. One participant was decolonised with topical fusidic acid after failure to decolonise with mupirocin. Dentists had a higher knowledge score compared with the other professionals (P < 0.05). Dental hygienists scored higher on practice questions compared with the other professionals (P < 0.05). There was a significant, positive correlation between attitude and practice scores (P < 0.01).. The nasal MRSA carriage rate among DHCPs is 2.9%, which is higher than that in the general population but lower than that in other health-care professionals. Further education of DHCPs on MRSA, especially regarding its seriousness, is needed to improve MRSA infection control in a dental hospital setting.

Topics: Attitude of Health Personnel; Clinical Competence; Cross-Sectional Studies; Dental Staff, Hospital; Female; Hospitals, University; Humans; Infection Control; Infectious Disease Transmission, Professional-to-Patient; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Practice Patterns, Dentists'; Republic of Korea; Staphylococcal Infections; Surveys and Questionnaires

This study aimed to screen for and characterise methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in nasal swabs and milk from healthy cows from different regions in Tunisia.. A total of 141 Staphylococcus spp. isolates were recovered from milk and nasal samples of cows. S. aureus isolates were further characterised by determining their antimicrobial susceptibilities, genes encoding antimicrobial resistance and virulence factors, biofilm production, agr type and PFGE. spa and SCCmec typing and MLST were also performed for the MRSA isolate.. Twenty-seven isolates (19.1%) were identified as S. aureus, of which 26 were MSSA and 1 was MRSA. The MSSA isolates were resistant to penicillin (73.1%), fusidic acid (61.5%), clindamycin (34.6%) and erythromycin (34.6%). The MRSA isolate, from a milk sample, was resistant to cefoxitin, penicillin, fusidic acid, amikacin and clindamycin. Twenty-five isolates (92.6%) had at least one enterotoxin gene. Only four isolates (14.8%) were positive for the tsst-1 gene. Genes encoding the exfoliative toxins D and A were detected in 9 (33.3%) and 6 (22.2%) isolates, respectively. The single MRSA isolate and 22 MSSA isolates were biofilm-producers on Congo red agar plates. Twelve pulsotypes were identified amongst 25 MSSA isolates revealing the clonal diversity of these isolates; however, one MSSA isolate was identified as CC398. The MRSA isolate was PVL-negative and was typed as ST97-t267-agrI-SCCmecV.. Contamination of milk with S. aureus, especially enterotoxin- and TSST-1-positive strains, poses a potential public-health threat. This is the first report of MRSA of bovine origin in Tunisia.

Topics: Animals; Anti-Bacterial Agents; Bacterial Toxins; Bacterial Typing Techniques; Cattle; Dairying; Drug Resistance, Multiple, Bacterial; Enterotoxins; Farms; Female; Genes, Bacterial; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Milk; Multilocus Sequence Typing; Nose; Staphylococcal Infections; Staphylococcus aureus; Superantigens; Tunisia; Virulence Factors

Our human model of nasal colonization and eradication of S. aureus is limited by safety issues. As rhesus macaques are closely related to humans and natural hosts for S. aureus, we developed an experimental decolonization and inoculation protocol in these animals. Animals were screened for nasal carriage of S. aureus and 20 carriers were selected. Decolonization was attempted using nasal mupirocin (10 animals) or mupirocin plus trimethoprim/sulfadiazine intramuscularly (10 animals) both once daily for 5 days, and checked by follow-up cultures for 10 weeks. Intranasal inoculation was performed with S. aureus strain 8325-4 in culture-negative animals. 11/20 animals, of which 5 received mupirocin and 6 the combination treatment, became culture-negative for S. aureus for 10 weeks and these 11 animals were subsequently inoculated. Swabs were taken once a week for 5 weeks to test for the presence of the inoculated strain. In 3 animals, strain 8325-4 was cultured from the nose 1 week after inoculation, indicating short-term survival of this strain only, a finding similar to that previously found in our human model. These data demonstrate that rhesus macaques may constitute a relevant animal model to perform S. aureus eradication and inoculation studies with relatively limited invasive handling of the animals.

Topics: Administration, Intranasal; Animals; Anti-Bacterial Agents; Carrier State; Disease Models, Animal; Drug Combinations; Female; Macaca mulatta; Male; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Sulfadiazine; Trimethoprim

Staphylococcus aureus cell wall anchored Serine Aspartate repeat containing protein D (SdrD) is a member of the microbial surface component recognising adhesive matrix molecules (MSCRAMMs). It is involved in the bacterial adhesion and virulence. However the extent of genetic variation in S. aureus sdrD gene within isolates from healthy carriers are not known. The aim of this study was to evaluate allelic variation of the sdrD gene among S. aureus from healthy nasal carriers.. The sdrD A region from 48 S. aureus isolates from healthy carriers were analysed and classified into seven variants. Variations in the sdrD A region were concentrated in the N2 and N3 subdomains. Sequence analysis of the entire sdrD gene of representative isolates revealed variations in the SD repeat and the EF motifs of the B repeat. In silico structural modelling indicates that there are no differences in the SdrD structure of the 7 variants. Variable amino acid residues mapped onto the 3D structure revealed that the variations are surface located, exist within the groove between the N2-N3 subdomains and distributed mainly on the N3 subdomain. Comparison of adhesion to keratinocytes in an in vitro cell adhesion assay, using NCTC 8325-4∆sdrD strains expressing the various sdrD gene variants, indicated a significant difference between only two complements while others showed no major difference in their adhesion.. This study provides evidence of sequence variations across the different domains of SdrD from S. aureus isolated from healthy nasal carriers. Proper understanding of these variations is necessary in the study of S. aureus pathogenesis.

Topics: Amino Acid Sequence; Bacterial Adhesion; Bacterial Proteins; Calcium-Binding Proteins; Cell Line; Genetic Variation; Humans; Keratinocytes; Models, Molecular; Multilocus Sequence Typing; Nose; Phylogeny; Protein Conformation; Protein Domains; Staphylococcal Infections; Staphylococcus aureus; Virulence

Despite WHO recommendations, there is currently no national screening and eradication policy for the detection of methicillin-sensitive Staphylococcus aureus (MSSA) in the UK prior to elective orthopaedic surgery. This study aimed to evaluate the effectiveness of current standard methicillin-resistant S. aureus (MRSA) eradication therapies in the context of S. aureus (both MRSA and MSSA) decolonization in an elective orthopaedic population.. A total of 100 patients awaiting joint replacement surgery who were positive for S. aureus on PCR nasal screening underwent the current standard MRSA pre-operative decolonization regimen for 5 days. Prior to commencement of the eradication therapy, swabs of the anterior nares, throat and perineum were taken for culture. Further culture swabs were taken at 48-96 h following treatment, at hospital admission for surgery and at hospital discharge. Following the completion of treatment, patients were asked to provide feedback on their experience using Likert rating scales. The primary outcome of this study was S. aureus clearance 48-96 h following eradication treatment.Results/Key Findings. Clearance of S. aureus 48-96 h following treatment was 94 % anterior nares, 66 % throat and 88 % groin. Mean completion with nasal mupirocin was 98 %. There was no statistically significant recolonization effect between the end of the eradication treatment period and the day of surgery (P>0.05) at a median time of 10 days.. Current MRSA decolonisation regimens are well tolerated and effective for MSSA decolonization for the anterior nares and groin. The decolonization effect is preserved for at least 10 days following treatment.

Topics: Aged; Anti-Bacterial Agents; Carrier State; Elective Surgical Procedures; Female; Humans; Male; Middle Aged; Mupirocin; Nasal Cavity; Nose; Orthopedics; Pharynx; Preoperative Care; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; United Kingdom

Staphylococcus aureus is a commensal and pathogenic bacterium with impact on public health and livestock industry. The study investigated nasal carriage, antibiotic resistance, and molecular characterization of S. aureus in pigs and pig workers. Nasal swabs from 300 backyard-raised pigs and 101 pig workers were used for the study. Resulting isolates were confirmed using MALDI-TOF MS, tested for antibiotic resistance, and three different multiplex PCRs were used to detect enterotoxin, mecA, spaA, scn, and pvl genes. spa typing was used to annotate the isolates into MLST clonal complexes (CC). Structured questionnaire was used to access possible risk factors for S. aureus carriage. The prevalence of S. aureus in pigs and pig workers were 5.3 and 12.9%, respectively. The isolates were resistant to beta-lactams (97%), tetracycline (62%), sulfonamide (52%), aminoglycoside (20.6%), fluoroquinolone (24%), and mupirocin (3.4%). Twenty seven (93%) of the isolates carried scn, 7(24%) pvl, and 12 (41%) enterotoxin genes, respectively. Questionnaire survey showed medical-related occupation of household members was associated (p < 0.5) with S. aureus carriage. This study suggests the presence of human multidrug resistant strains of S. aureus, high carriage of pvl, and enterotoxin genes, and CC5, CC15, and CC152 were the CC-groups shared among pigs and pig workers.

Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Female; Humans; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Multiplex Polymerase Chain Reaction; Nose; Occupational Exposure; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires; Swine; Tetracycline

Nasopharyngeal swabs from 148 adult patients with influenza were analyzed by polymerase chain reaction for Staphylococcus aureus and or Streptococcus pneumoniae. We found that patients colonized with S. pneumoniae were younger, had lower oxygen saturations, and were more likely to require admission to critical care.

Topics: Aged; Aged, 80 and over; Coinfection; Female; Humans; Influenza A virus; Influenza, Human; Male; Middle Aged; Nose; Pneumococcal Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae

Objective This study was performed to determine the prevalence and risk factors associated with nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization upon intensive care unit (ICU) admission and during the ICU stay in mainland China. Methods A prospective observational study was performed in a 50-bed general ICU of a 4300-bed teaching hospital in China from 2011 to 2013. Nasal swabs for MRSA detection were obtained upon ICU admission and at discharge for patients having stayed in the ICU for longer than 3 days. Results In total, 115 patients (4.1%; 95% confidence interval [CI], 3.4-4.9) were already colonized with MRSA on ICU admission, and another 185 patients (10.7%; 95% CI, 9.3-12.2) acquired MRSA during their ICU stay. Development of an MRSA infection was significantly more likely in patients with than without MRSA colonization on ICU admission (odds ratio [OR], 2.8; 95% CI, 1.1-7.3). Patients who acquired MRSA had significantly prolonged lengths of stay in the ICU (23.3 days) and higher hospital bills (135,171 RMB; about 19,590 USD) than those who tested negative for MRSA. Conclusion The MRSA colonization rate among ICU patients in mainland China is high. Patients with MRSA-positive nasal swabs are more likely to develop MRSA infections.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; China; Female; Hospitals, University; Humans; Infant; Infant, Newborn; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Young Adult

The study objective was to determine the prevalence of Staphylococcus aureus colonisation in the nares and oropharynx of healthy persons and identify any risk factors associated with such S. aureus colonisation. In total 263 participants (177 adults and 86 minors) comprising 95 families were enrolled in a year-long prospective cohort study from one urban and one rural county in eastern Iowa, USA, through local newspaper advertisements and email lists and through the Keokuk Rural Health Study. Potential risk factors including demographic factors, medical history, farming and healthcare exposure were assessed. Among the participants, 25.4% of adults and 36.1% minors carried S. aureus in their nares and 37.9% of adults carried it in their oropharynx. The overall prevalence was 44.1% among adults and 36.1% for minors. Having at least one positive environmental site for S. aureus in the family home was associated with colonisation (prevalence ratio: 1.34, 95% CI: 1.07-1.66). The sensitivity of the oropharyngeal cultures was greater than that of the nares cultures (86.1% compared with 58.2%, respectively). In conclusion, the nares and oropharynx are both important colonisation sites for healthy community members and the presence of S. aureus in the home environment is associated with an increased probability of colonisation.

Topics: Adolescent; Adult; Aged; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Iowa; Male; Middle Aged; Nose; Oropharynx; Prevalence; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Young Adult

In 2016, the workflow for MRSA detection in nasal swabs was changed from a classic-manual workflow to an automated workflow using total lab automation (TLA; BD Kiestra). This change entailed a reduction of the incubation time from 2 days to 20 h and reading of plates on weekdays and weekends instead of weekdays only. The workflow alteration did not include the introduction of 24/7. We wanted to follow up on the consequences for the times to report (TTR). We compared the TTR of all nasal swabs, which were sent for MRSA detection from June until August in 2015 (workflow-classic-manual) and in 2016 (workflow-automated). We calculated median TTR and interquartile ranges for the three possible reporting outcomes (negative, MRSA-known, MRSA-new) per day and workflow. A multivariable linear regression modeled the exposure variables workflow, day, and reporting outcome on TTR including interaction variables. The quantity and reasons for a TTR longer than 3 days were analyzed. During both 3-month periods, a total of 16,111 reports were issued (2015:7620; 2016:8491). The median TTR for negative reports was 48:28 (hh:mm) in 2015 and 23:58 in 2016. In the linear regression, all exposure variables had a strong and highly significant (p < 0.001) influence on the TTR. The number of reports with a TTR longer than 3 days shrank from 2418 (2015) to 60 (2016). The workflow alteration halved the median TTR for negative reports and the number of reports with a TTR longer than 3 days was reduced by 97.5%.

Topics: Automation, Laboratory; Humans; Linear Models; Methicillin-Resistant Staphylococcus aureus; Nose; Reading; Staphylococcal Infections; Time Factors; Workflow

Healthcare workers frequently come into contact with infected individuals and are at a greater risk of infection than the general population due to their occupation. Multidrug-resistant organisms (MDROs) also pose a significant challenge for personnel and medical facilities. Currently, little is known about the occupational risk of methicillin-resistant. MRSA screening with nasal swabs was carried out, the known risk factors for colonisation were determined and information on infection control was inquired. Where tests were positive, a control swab was taken; if this confirmed a positive result, decolonisation was offered. A molecular biological examination of the MRSA samples was performed. The occupational MRSA exposure and risk factors were compared with the situation for personnel in inpatient geriatric care.. A total of 39 outpatient services participated in the study and 579 employees were tested. The MRSA prevalence was 1.2% in all and 1.7% in nursing staff. Most of the employees that tested positive had close or known contact with MRSA patients. Health personnel frequently reported personal protective measures and their application. Compared with inpatient care staff, outpatient staff were older and had worked in their profession for a longer time.. This study marks the first time that data has been made available on the occupational MRSA risk of outpatient care personnel in Hamburg. The MRSA prevalence is low and provides a good basis for describing the MRSA risk of occupational exposure by health personnel in outpatient care.

Topics: Adult; Ambulatory Care Facilities; Carrier State; Cross-Sectional Studies; Female; Germany; Health Personnel; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Nursing Staff; Occupational Diseases; Occupational Exposure; Prevalence; Risk Factors; Staphylococcal Infections

The prevalence of nasal carrier status of methicillin-resistant Staphylococcus aureus (MRSA) in pigs has been described elsewhere, but is unknown in South Africa. To address concerns that exist regarding the zoonotic risk that carriers pose to workers, the herd-level prevalence of MRSA was determined among 25 large (> 500 sows) commercial pig herds in South Africa, representing 45% of the large commercial herds in the country. From each herd, the nasal contents of 18 finisher pigs were sampled at the abattoir, pooled into three and selectively cultured to determine the presence of MRSA. A herd was classified as MRSA-positive if one or more of the three pooled samples cultured positive. Three of the 25 herds tested positive for MRSA, equating to a 12% herd prevalence (95% CI: 7% - 23%) among South African commercial piggeries. The prevalence of nasal MRSA carriers among large commercial pig herds in South Africa was low compared to what has been reported elsewhere and suggests a relatively low zoonotic MRSA risk to workers in South African commercial piggeries and abattoirs.

Topics: Animals; Female; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; South Africa; Staphylococcal Infections; Swine; Swine Diseases

Staphylococcus aureus is a commensal and pathogen of both humans and bovines. While the epidemiology of both groups has been extensively studied individually, little is known about the potential zoonotic transfer from animal strains to human being and vice versa. To determine the S. aureus prevalence of bovine mastitis in Algeria and the zoonotic transfer of strains to human beings, mastitis milk samples were collected, and professionals in a close contact with bovines were nasal swabbed. S. aureus isolates were all characterized by methicillin resistance and spa-typing. DNA microarrays analysis was performed on a subset of strains in order to detect other virulence factors, including toxins, and to assign the isolates to theirs MLST clonal complexes. Overall, 116/222 (52.3%) cows suffered from mastitis, whose 38.8% (45/116) infected with S. aureus. Human nasal carriage was of 38% (49/129), with only 4 MRSA carriers (3.1%). A higher diversity of spa-types was observed in human (35/50) than in bovine (18/67) isolates, with a predominance of clonal complexes CC97 and CC22 in bovines. The typical animal clone CC97 was occasionally detected in human beings. Conversely, the CC22 S. aureus clone largely switched from humans to bovines. Our study highlights the potential dynamics of animal and human S. aureus strains in the farm environment in Algeria, which may represent a health threat in both populations.

Topics: Animals; Bacterial Typing Techniques; Carrier State; Cattle; Female; Geography; Host Specificity; Humans; Mastitis, Bovine; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Multilocus Sequence Typing; Nose; Oligonucleotide Array Sequence Analysis; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

Topics: Aptamers, Nucleotide; Bacterial Proteins; Fluorometry; Humans; Immunomagnetic Separation; Limit of Detection; Methicillin-Resistant Staphylococcus aureus; Mucoproteins; Nose; Penicillin-Binding Proteins; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections

The purpose of this study is to investigate the prevalence of MRSA among people living with HIV/AIDS (PLHA) being monitored in a tertiary outpatient hospital in the state of Pernambuco, in the Brazilian Northeast.. Staphylococcus aureus was isolated from a nasal swab and found in 31.4% of the individuals (95% CI 27.3-35.5), of whom 4.4% (95% CI 8.5-19.5) were MRSA, as confirmed by the presence of the mecA gene. For individuals whose S. aureus was recovered, the mean age was 41.5 years; 93.6% were on antiretroviral treatment. This group had CD4 cell counts > 200 (92%) and viral load ≤ 100 copies (79.1%). Use of antimicrobial agents in the past 12 months was found among 21% of the individuals, and 24.2% reported use of illicit drugs at lease once in their lifetime. Prevalence of nasal colonization by MSSA (26.7%) and MRSA (4.4%) was higher in comparison to other studies of this population; nevertheless, we were unable to establish factors associated with risk.

Topics: Acquired Immunodeficiency Syndrome; Adult; Brazil; Comorbidity; Cross-Sectional Studies; Female; HIV Infections; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Outpatients; Staphylococcal Infections; Tertiary Care Centers

Colonization by Staphylococcus aureus is regularly assessed in patients undergoing major heart surgery (MHS). Despite pre-surgical decontamination attempts, a significant proportion of MHS patients remain colonized by S. aureus at the time of surgery. Nasal sampling can be improved by sampling extra-nasal areas. We evaluated whether processing lower respiratory tract (LRT) secretions enhanced the detection of S. aureus after MHS. Following a standard protocol, nasal swabs and LRT aspirates were obtained from all of the study patients at the time of surgery or in the immediate postoperative period. One swab was used for culture in the microbiology laboratory, and a second swab was used for the Xpert SA Nasal Complete assay. According to our definition of colonization (culture positive and/or PCR positive), 31 of 115 patients (26.9%) were colonized at the time of surgery. Among these, LRT samples only were positive in three patients (2.6% of the whole population and 9.7% of the carriers). The remaining 28 were either positive in the nasal sample or positive in both samples. The yield of the detection of colonization by S. aureus by including also LRT samples in patients undergoing MHS is limited and must be balanced with laboratory workload and demands on laboratory personnel. Trial registration: Clinical trials.gov NCT02640001.

Topics: Aged; Cardiac Surgical Procedures; Carrier State; Female; Humans; Male; Middle Aged; Nose; Postoperative Complications; Prospective Studies; Respiration, Artificial; Respiratory System; Risk Factors; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

Carriage of Staphylococcus aureus in the nose appears to play a key role in the epidemiology and pathogenesis of infection. It is important to investigate the genetic relatedness of S. aureus and MRSA clones in different geographic regions. The aim of this study was to assess the nasal carriage rate of S. aureus, including MRSA strains in both hospitalized children and general adult population (parents/guardian). In addition, antibiotic susceptibility pattern and molecular diversity of S. aureus in both population was evaluated in an Iranian referral pediatrics Hospital.. All samples were obtained through nasal screening of patients and general adult population at admission and discharge day. The prevalence, resistance, and molecular diversity of all S. aureus isolates were examined.. In the current study, nasal carriage of S. aureus and Staphylococcus non aureus was identified in 384 (26%) and 1004 (68%) of the study population. The prevalence of MRSA nasal carriage in children and adults was 6.6% (29 out of 438) and 2.8% (29 out of 1046), respectively. Among S. aureus strains isolated obtained from patients and general adult population at admission day, high sensitivity to most of the antibiotics such as vancomycin (100%), rifampin (95%), linezolid (94%), quinupristin/dalfopristin (94%), minocycline (94%), chloramphenicol (89%), gentamycin (87%), amikacin (87%), clindamycin (86%) and moxifloxacin (83%) was seen. The most resistance antibiotics were penicillin (96-98%) and methicillin (44-47%). The susceptibility patterns of nasal S. aureus strains isolated at discharge day was not statistically different from S. aureus isolates obtained at admission day. Admission S. aureus isolated strains of 77 patients (64%) were similar to the isolated S. aureus strains of discharge, while S. aureus isolated strains of 43 patients (36%) was not similar to the strain of discharge (had similarity of less than 70%).. High prevalence of nasal carriage of S. aureus and MRSA indicates the urgent need to improve strategies for management of S. aureus infections. Our findings are useful for understanding of S. aureus nasal colonization dynamics within the patients and general population. Surveillance for S. aureus in community settings can provide data on circulating strains and might help developing control measures for reducing of infection spread in hospitals.

Topics: Adult; Anti-Bacterial Agents; Child; Child, Preschool; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Genetic Variation; Genotyping Techniques; Humans; Infant; Iran; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Epidemiology; Nose; Parents; Prevalence; Referral and Consultation; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Colonization of the body is an important step in Staphylococcus aureus infection. S. aureus colonizes skin and mucous membranes in humans and several animal species. One important ecological niche of S. aureus is the anterior nares. More than 60% of the S. aureus in the nose are found in vestibulum nasi. Our aim was to describe the localization of S. aureus in nasal tissue from healthy carriers.. Punch skin biopsies were taken from vestibulum nasi from healthy volunteers (S. aureus carriers and non-/intermittent carriers, n = 39) attending the population-based Tromsø 6 study. The tissue samples were processed as frozen sections before immunostaining with a specific S. aureus antibody, and finally evaluated by a confocal laser-scanning microscope.. Our results suggest that S. aureus colonize both the upper and lower layers of the epidermis within the nasal epithelium of healthy individuals. The number of S. aureus in epidermis was surprisingly low. Intracellular localization of S. aureus in nasal tissue from healthy individuals was also detected.. Knowledge of the exact localization of S. aureus in nasal tissue is important for the understanding of the host responses against S. aureus. Our results may have consequences for the eradication strategy of S. aureus in carriers, and further work can provide us with tools for targeted prevention of S. aureus colonisation and infection.

Topics: Adult; Biopsy; Carrier State; Colony Count, Microbial; Cross-Sectional Studies; Epithelial Cells; Female; Host-Parasite Interactions; Humans; Male; Microscopy, Confocal; Nasal Cavity; Nasal Mucosa; Norway; Nose; Skin; Staphylococcal Infections; Staphylococcus aureus

The aim of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) compared with non-HCWs at Duhok city, Kurdistan Region, northern Iraq.. A total of 182 HCWs with different occupations and working in different hospital units as well as 198 non-HCWs were recruited. Nasal swab samples were collected and were inoculated on mannitol salt agar and incubated at 35°C for 48h. Isolates identified as S. aureus underwent antimicrobial sensitivity testing to oxacillin. MRSA isolates were selected and investigated for presence of the mecA gene.. Among the HCWs, 41/182 (22.5%) were carriers of S. aureus compared with 37/198 (18.7%) non-HCWs (P=0.4). Amongst the S. aureus carriers, 25/41 strains (61.0%) isolated from HCWs were MRSA compared with 8/37 strains (21.6%) isolated from non-HCWs (P=0.039). The mean age of MRSA carriers was 35.6±6.7years compared with 30±5.8years for MRSA non-carriers (P=0.0177). The mean working years of MRSA carriers was significantly higher than that of MRSA non-carriers (7.8±5.5years vs. 3.9±5.3years; P=0.04).. The prevalence of MRSA was very high amongst HCWs. Regular screening of carriers is required for prevention of nosocomial infections.

Topics: Adult; Age Factors; Anti-Bacterial Agents; Bacterial Proteins; Carrier State; Female; Health Personnel; Hospitals; Humans; Iraq; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Oxacillin; Penicillin-Binding Proteins; Prevalence; Staphylococcal Infections; Young Adult

Staphylococcus epidermidis, a major component of skin flora, is an opportunist, often causing prosthetic device infections. A family of structurally related proteins mediates staphylococcal attachment to host tissues, contributing to the success of S. epidermidis as a pathogen. We examined the ability of the surface protein SdrF to adhere to keratin, a major molecule expressed on the skin surface.. A heterologous Lactococcus lactis expression system was used to express SdrF and its ligand-binding domains. Adherence to keratin types 1 and 10, human foreskin keratinocytes, and nasal epithelial cells was examined.. SdrF bound human keratins 1 and 10 and adhered to keratinocytes and epithelial cells. Binding involved both the A and B domains. Anti-SdrF antibodies reduced adherence of S. epidermidis to keratin and keratinocytes. RNA interference reduced keratin synthesis in keratinocytes and, as a result, SdrF adherence. Direct force measurements using atomic force microscopy showed that SdrF mediates bacterial adhesion to keratin 10 through strong and weak bonds involving the A and B regions; strong adhesion was primarily mediated by the A region.. These studies demonstrate that SdrF mediates adherence to human keratin and suggest that SdrF may facilitate S. epidermidis colonization of the skin.

Topics: Bacterial Adhesion; Bacterial Proteins; Epithelial Cells; Humans; Keratin-1; Keratin-10; Keratinocytes; Lactococcus lactis; Membrane Proteins; Membrane Transport Proteins; Microscopy, Atomic Force; Nose; Protein Binding; Staphylococcal Infections; Staphylococcus epidermidis

Staphylococcus aureus is a versatile bacterium, which can infect or colonize a variety of host species. The objective of this study was to characterize S. aureus isolates recovered from nasal swabs of 167 healthy ewes sampled from 12 farms in different areas of Tunisia during the period of 2014-2015. Genetic lineages, virulence factors and antibiotic resistance mechanisms were determined for recovered isolates. S. aureus was detected in 45 out of 167 tested samples (26.9%). All isolates were methicillin-susceptible (MSSA) and the majority of them were susceptible to tested antibiotics with few exceptions (% of resistance): penicillin (8.8), ciprofloxacin (4.4), and tobramycin or tetracycline (2.2, each). Twelve different spa types were detected (t15098, t15099, t1773, t3576, t1534, t5428, t3750, t5970 t254, t2883, t127 and t933), two of them were new (t15098 and t15099). S. aureus isolates were ascribed to agrI (n=23), agrII (n=1) and agrIII (n=20), and one was non-typeable. According to the sequence-type (ST) determined and/or the spa-type detected, the 45S. aureus isolates were assigned to six clonal complexes, with CC522 (44.4%) and CC130 (37.7%) being the most common lineages. Twenty-one (46.6%) and two (4.2%) isolates harbored the tst and eta genes encoding TSST-1 and ETA, respectively. In conclusion, nares of healthy ewes could be a reservoir of MSSA CC522 and CC130, lineages associated with TSST-1 and ETA that might represent a risk to human health.

Topics: Animals; Anti-Bacterial Agents; Bacterial Toxins; Disease Reservoirs; Enterotoxins; Female; Microbial Sensitivity Tests; Nose; Prevalence; Sheep; Sheep Diseases; Staphylococcal Infections; Staphylococcus aureus; Superantigens; Tunisia; Virulence Factors

We assessed the impact of preoperative Staphylococcus aureus screening and targeted decolonization on the incidence of postoperative methicillin-resistant S aureus (MRSA) colonization, intensive care unit MRSA transmission, and surgical site infections in cardiac surgery patients.. We reviewed medical records for all adult patients during two periods: preintervention (January 2007 to April 2010) and intervention (January 2011 to December 2014). In the intervention period, we performed nasal screening for methicillin-sensitive S aureus and MRSA using polymerase chain reaction within 30 days of the operation. Colonized patients received intranasal mupirocin twice daily and chlorhexidine baths daily for 5 days; patients colonized with MRSA also received prophylactic vancomycin plus cefazolin with contact isolation precautions. Nasal surveillance for MRSA was performed on intensive care unit admission and weekly thereafter. Multivariable logistic regression models were constructed to determine risk factors for postoperative MRSA colonization, and surgical site infections and the impact of our screening program was assessed in these models. Poisson regression was used to assess MRSA transmission.. Comparing 2,826 preintervention and 4,038 intervention patients, cases differed in age, diabetes mellitus, preoperative infection, preoperative length of stay, and bypass time (all p ≤ 0.03). Intervention patients had risk-adjusted reductions in MRSA colonization (odds ratio 0.53, 95% confidence interval [CI]: 0.37 to 0.76, p < 0.001), transmission (incidence rate ratio 0.29, 95% CI: 0.13 to 0.65, p = 0.002), and surgical site infections (odds ratio 0.58, 95% CI: 0.40 to 0.86, p = 0.007). Increased duration of preoperative decolonization therapy was associated with decreased postoperative MRSA colonization (odds ratio 0.73, 95% CI: 0.53 to 1.00, p = 0.05).. Preoperative S aureus screening with targeted decolonization was associated with reduced MRSA colonization, transmission, and surgical site infections. Duration of preoperative therapy correlated with decreased frequency of postoperative MRSA colonization.

Topics: Administration, Intranasal; Adult; Aged; Anti-Infective Agents; Cardiac Surgical Procedures; Carrier State; Chlorhexidine; Female; Humans; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

The nosocomial prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Portugal is close to 50% and remains one of the highest in Europe. MRSA reservoirs in the animal setting in Portugal have been very poorly investigated, namely among animal husbandry. A total of 52 samples (nasal, inguinal region, and milk) were obtained from bovine animals and analyzed for the presence of S. aureus. The isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, SCCmec typing, and multilocus sequence typing and tested for antimicrobial susceptibility, presence of mecA and mecC genes, and virulence determinants. Overall, 54% of the screened animals were colonized with S. aureus in at least one body site. Notably, S. aureus nasal carriage followed an increasing trend with animal age (p = 0.0006). None of the isolates harbored the mecA or mecC genes. Resistance to penicillin, rifampicin, and tetracycline was observed in 24%, 18%, and 6% of the isolates, respectively. The isolates were distributed into three clonal lineages: PFGE type A, spa type t1166, ST1247-CC133 (43%), PFGE B-t267-ST352-CC97 (30%), and PFGE C-t091-ST7-CC7 (27%). CC133 was associated to older animals (p = 0.0025), whereas CC97 was isolated from calves (p = 0.0016). Virulence determinants commonly found in mastitis were widely detected in carriage isolates: lukDE and hlgv (100%), hlb (76%), and lukM (35%). Although healthy bovines do not represent a MRSA reservoir in Portugal, they are mainly colonized with S. aureus pathogenic lineages associated to mastitis in cattle (CC97 and CC133).

Topics: Age Factors; Animals; Anti-Bacterial Agents; Asymptomatic Infections; Carrier State; Cattle; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Milk; Multilocus Sequence Typing; Nose; Portugal; Prevalence; Staphylococcal Infections

We apply two different sensitivity techniques to a model of bacterial colonization of the anterior nares to better understand the dynamics of Staphylococcus aureus nasal carriage. Specifically, we use partial rank correlation coefficients to investigate sensitivity as a function of time and identify a reduced model with fewer than half of the parameters of the full model. The reduced model is used for the calculation of Sobol' indices to identify interacting parameters by their additional effects indices. Additionally, we found that the model captures an interesting characteristic of the biological phenomenon related to the initial population size of the infection; only two parameters had any significant additional effects, and these parameters have biological evidence suggesting they are connected but not yet completely understood. Sensitivity is often applied to elucidate model robustness, but we show that combining sensitivity measures can lead to synergistic insight into both model and biological structures.

Topics: Carrier State; Humans; Mathematical Concepts; Methicillin-Resistant Staphylococcus aureus; Models, Biological; Nose; Risk Factors; Staphylococcal Infections

There is limited data on methicillin-resistant Staphylococcus aureus (MRSA) carriage in dental clinics. 1300 specimens from patients, health personnel, and environmental surfaces of a dental clinic in Egypt were tested for MRSA. Antibiotic susceptibility, biofilm formation, Staphylococcal protein A (spa) typing, SCCmec typing, and PCR-based assays were used to detect mecA, mecC, vanA, Panton-Valentine Leukocidin toxin (PVL), and toxic shock syndrome toxin-1 (tst) genes. Among 34 mecA-positive MRSA isolates, five (14.7%) were PVL-positive, seventeen (50%) were tst-positive, ten (29.4%) were vanA-positive, while none harboured mecC. MRSA hand carriage rates in patients, nurses, and dentists were 9.8%, 6.6%, and 5%. The respective nasal colonization rates were 11.1%, 6.7%, and 9.7%. 1.3% of the environmental isolates were MRSA-positive. Strong and moderate biofilm-forming isolates represented 23.5% and 29.4% of MRSA isolates. 24 MRSA isolates (70.6%) were multi-resistant and 18 (52.9%) harboured SCCmec IV. Among eight spa types, t223 (26.5%), t267 (23.5%), and t14339 (23.5%) were predominant. We noted an alarming genetic relatedness between 7 (20.6%) MRSA isolates and the epidemic EMRSA-15 clone, as well as a combined occurrence of tst and PVL in 3 (8.8%) isolates. Results suggest high MRSA pathogenicity in dental wards highlighting the need for more efficient surveillance/infection control strategies.

Topics: Bacterial Proteins; Biofilms; Carrier State; Cross-Sectional Studies; Dental Clinics; Egypt; Environmental Microbiology; Evolution, Molecular; Hand; Health Personnel; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Typing; Nose; Phylogeny; Staphylococcal Infections; Tooth Diseases

To investigate the conjunctival and nasal flora and the antibiotic susceptibility profiles of isolates from patients undergoing cataract surgery.. Observational and cross-sectional study.. A single-centre study in Taiwan.. 128 consecutive patients precataract surgery.. Conjunctival and nasal cultures were prospectively obtained from 128 patients on the day of cataract surgery before instillation of ophthalmic solutions in our hospital. Isolates and antibiotic susceptibility profiles were identified through standard microbiological techniques. Participants were asked to complete a questionnaire on healthcare-associated factors.. The positive culture rate from conjunctiva was 26.6%, yielding 84 isolates. Coagulase-negative

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Cataract; Cataract Extraction; Conjunctiva; Cross-Sectional Studies; Drug Resistance; Female; Fluoroquinolones; Humans; Male; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus; Taiwan; Tobramycin; Vancomycin; Vancomycin Resistance

This study was performed to investigate the concordance in terms of molecular characteristics and antimicrobial susceptibility between colonizing and clinical Staphylococcus aureus isolates obtained from children in Korea, where ST72 is the major genotype.This was a prospective observational descriptive study of culture-confirmed S aureus infections obtained from children ≤18 years old admitted to Asan Medical Center Children's Hospital in Seoul, Korea, from March 2014 to April 2015. Molecular studies including multilocus sequence typing (MLST), SCCmec typing, polymerase chain reaction amplification of the Panton-Valentine leukocidin (PVL) genes, and antibiotic susceptibility tests were performed on S aureus isolates obtained from nares and clinical specimens.During the study period, 126 clinically significant S aureus infections were identified. Nasal swab cultures were made from 113 of the 126 children, and 46.0% (52/113) showed S aureus colonization. The overall concordance between colonizing and clinical isolates by methicillin susceptibility was 94.2% (49/52); all 3 discordant cases were HA-MSSA cases with nasal MRSA. Among the 37 pairs of colonizing and clinical S aureus isolates included in the genotyping analysis, ST72-SCCmec type IV was the most prevalent clone and the PVL genes were positive in 2 patients. Among the 31 pairs of healthcare-associated cases, concordance rates by methicillin susceptibility and sequence type (ST) were 90.3% (28/31) and 84% (26/31), respectively. For the 6 pairs of community-associated (CA) S aureus including 3 CA-MRSA cases, 100% concordance was observed by methicillin susceptibility and ST.The concordance between isolates obtained from children who required medical services was relatively high in Korean children where ST72-SCCmec type IV is the predominant clone as the colonizer and the pathogen. It is suggested that decolonization and continuous care to prevent transmission could be effective in managing and preventing both HA- and CA-SA infections in our setting.

Topics: Child; Child, Preschool; Community-Acquired Infections; Cross Infection; Drug Resistance, Bacterial; Female; Genotype; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Prospective Studies; Republic of Korea; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is a major pathogen causing significant morbidity and mortality worldwide. The emergence of MDR S. aureus strains in the community setting has major implications in disease management. However, data regarding the occurrence and patterns of MDR community-associated S. aureus sub-clones is limited.. To use whole-genome sequences to describe the diversity and distribution of resistance mechanisms among community-associated S. aureus isolates.. S. aureus isolates from skin and soft tissue infections (SSTIs) and nasal colonization were collected from patients within 10 primary care clinics from 2007 to 2015. The Illumina Miseq platform was used to determine the genome sequences for 144 S. aureus isolates. Phylogenetic and bioinformatics analyses were performed using in silico tools. The resistome was assembled and compared with the phenotypically derived antibiogram.. Approximately one-third of S. aureus isolates in the South Texas primary care setting were MDR. A higher proportion of SSTI isolates were MDR in comparison with nasal colonization isolates. Individuals with MDR S. aureus SSTIs were more likely to be African American and obese. Furthermore, S. aureus populations are able to acquire and lose antimicrobial resistance genes. USA300 strains were differentiated by a stable chromosomal mutation in gyrA conferring quinolone resistance. The resistomes were highly predictive of antimicrobial resistance phenotypes.. These findings highlight the high prevalence and epidemiological factors associated with MDR S. aureus strains in the community setting and demonstrate the utility of next-generation sequencing to potentially quicken antimicrobial resistance detection and surveillance for targeted interventions.

Topics: Adult; Anti-Bacterial Agents; Community-Acquired Infections; Drug Resistance, Multiple, Bacterial; Female; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Humans; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Phylogeny; Prevalence; Soft Tissue Infections; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; United States; Young Adult

Little is known about neonatal Staphylococcus aureus carriage. Sites and clinical outcomes of S. aureus colonization during the first month of life were evaluated in this study.. A cohort of 279 infants born at term to 277 mothers was included. Maternal S. aureus colonization status was examined before labor. Newborns were screened for nasal, auricular, umbilical, and rectal colonization, one to three times within 100h after birth, and infants of carrier mothers were re-screened at 1 month. Medical data were recorded from the medical charts at discharge and at the 1-month follow-up interview.. Overall 43 out of 279 (15.4%) infants acquired S. aureus within the first days of life. The only two predictors of S. aureus carriage in the postnatal period were maternal S. aureus carriage (odds ratio 7.905, 95% confidence interval 3.182-19.638) and maternal antibiotic treatment during labor (odds ratio 0.121, 95% confidence interval 0.016-0.949). Among colonized children, the nose (56%) and rectum (40%) were more frequently colonized, while ear (26%) and umbilicus (16%) colonization were less common. Co-colonization at two sites was rare (4%), but always predicted carriage at 1 month of age. Maternal and neonatal characteristics, including neonatal outcomes, were similar between S. aureus carrier and non-carrier infants during the first month of life.. Maternal carriage is the major predictor of neonatal S. aureus carriage. The nose and rectum are the main sites of neonatal carriage. S. aureus carriage was not associated with neonatal complications throughout the first month of life. The long-term significance of early S. aureus carriage is yet to be determined.

Topics: Adult; Carrier State; Child; Cohort Studies; Ear; Female; Humans; Infant; Infant, Newborn; Male; Mothers; Nose; Odds Ratio; Outcome Assessment, Health Care; Pregnancy; Pregnancy Complications, Infectious; Rectum; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Umbilicus

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multidrug-resistant organisms in healthcare settings worldwide, but little is known about MRSA transmission outside of acute healthcare settings especially in Asia. We describe the methods for a prospective longitudinal study of MRSA prevalence and transmission.. MRSA-colonized individuals were identified from MRSA admission screening at two tertiary hospitals and recruited together with their household contacts. Participants submitted self-collected nasal, axilla and groin (NAG) swabs by mail for MRSA culture at baseline and monthly thereafter for 6 months. A comparison group of households of MRSA-negative patients provided swab samples at one time point. In a validation sub-study, separate swabs from each site were collected from randomly selected individuals, to compare MRSA detection rates between swab sites, and between samples collected by participants versus those collected by trained research staff. Information on each participant's demographic information, medical status and medical history, past healthcare facilities usage and contacts, and personal interactions with others were collected using a self-administered questionnaire.. Understanding the dynamics of MRSA persistence and transmission in the community is crucial to devising and evaluating successful MRSA control strategies. Close contact with MRSA colonized patients may to be important for MRSA persistence in the community; evidence from this study on the extent of community MRSA could inform the development of household- or community-based interventions to reduce MRSA colonization of close contacts and subsequent re-introduction of MRSA into healthcare settings. Analysis of longitudinal data using whole-genome sequencing will yield further information regarding MRSA transmission within households, with significant implications for MRSA infection control outside acute hospital settings.

Topics: Adult; Community-Acquired Infections; Family Characteristics; Health Facilities; Humans; Longitudinal Studies; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Prospective Studies; Singapore; Staphylococcal Infections; Surveys and Questionnaires; Tertiary Care Centers

The aims of this cross-sectional study were to determine the prevalence of Staphylococcus aureus nasal colonization, evaluate community-related behavioral risk factors, and utilize staphylococcal protein A (spa) typing for epidemiological surveillance among community-based men who have sex with men from the National HIV Behavioral Surveillance System in Houston, Texas.. Descriptive methods and logistic analyses were used to determine associations with nasal colonization.. The prevalence of S. aureus colonization was 29.7%; of these, 3.0% were colonized with methicillin-resistant S. aureus. Logistic analyses revealed that anal intercourse practices were associated with colonization (P < 0.05). A diverse population of 38 spa types was identified.. Our findings suggest that an association among preferential sex practices, condom use, and S. aureus colonization exists and should be investigated further.

Topics: Adult; Community-Based Participatory Research; Cross-Sectional Studies; Homosexuality, Male; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Risk-Taking; Staphylococcal Infections; Staphylococcal Protein A; Staphylococcus aureus

There are few epidemiological data available to inform a national response to community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in Papua New Guinea (PNG).. We performed a cross-sectional survey to determine the pattern of MRSA nasal colonization and the diversity of circulating MRSA clones among adults and adolescents in Madang Province, PNG.. S. aureus nasal colonization was confirmed in 44 (17.1%) of 257 participants. Four (9.1%) isolates were methicillin resistant. Resistance to other antimicrobial agents was uncommon. Detailed molecular typing of three MRSA isolates demonstrated multiple MRSA clones in this community, of which two carried the Panton-Valentin leukocidin-associated virulence genes.. MRSA is likely to account for a clinically important proportion of staphylococcal disease in PNG. There are multiple MRSA clones in PNG. Ongoing surveillance of community and invasive isolates is a critical component of an effective response to the challenge of community-acquired MRSA in this and many other resource-limited contexts.

Topics: Adolescent; Adult; Community-Acquired Infections; Cross-Sectional Studies; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Papua New Guinea; Prevalence; Staphylococcal Infections; Virulence Factors; Young Adult

Diabetic population were reported more likely to suffer carriage and infection with Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA) than non-diabetic population. We aim to elucidate the prevalence and characteristics of S. aureus and MRSA nasal carriage among diabetic population in the United States National Health and Nutrition Examination Survey, 2001-2004. Univariate analyses were conducted using Chi-square test, Fisher's exact probability test or student t test, as appropriate. Multivariate analy¬sis using logistic regression was conducted to assess the association between influencing factors and S. aureus and MRSA nasal carriage. 1010 diabetic participants were included in the study. The prevalence of S. aureus and MRSA nasal carriage were 28.32% and 1.09%, respec¬tively. After the logistic regression, ever had a painful sensation or tingling in hands or feet past three months (Odds Ratio [OR] = 0.359, 95% Confidence Interval [CI], 0.146-0.882) was significant among S. aureus nasal carriage and gender (OR = 3.410, 95% CI, 1.091-10.653) was significant among MRSA nasal carriage. The proportions of staphylococcal enterotoxin (SE) A, SEB, SEC, SED, Toxic-shock syn¬drome toxin-1, and Panton Valentine Leukocidin toxin among S. aureus strains were 18.75%, 3.13%, 12.50%, 15.63%, 28.13%, and 9.38%, respectively. 63.63% of MRSA strains were community-acquired, 27.27% were hospital-acquired, and 9.09% were non-typeable. Diabetic patients might be more likely to carry S. aureus and MRSA in the United States. Improving hand hygiene compliance, reducing antibiotic overuse, screening for carriers, and decolonization are recommended to reduce the spread of S. aureus and MRSA, especially in community.

Topics: Anti-Bacterial Agents; Bacterial Toxins; Carrier State; Diabetes Complications; Drug Resistance, Bacterial; Enterotoxins; Exotoxins; Female; Humans; Leukocidins; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Multivariate Analysis; Nose; Nutrition Surveys; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United States

There are only few data on the persistence and transmission of methicillin resistant Staphylococcus aureus (MRSA) of the clonal complex (CC) 398 among veterinarians and their household members. We therefore investigated the long-term colonisation with MRSA CC398 among participants of veterinary conferences in Germany in 2008/2009 and their household members. Forty-five initially MRSA CC398 positive and 180 initially MRSA CC398 negative conference participants were included in a longitudinal study. These persons and their household members were tested for nasal colonisation in 2011, 2012 and 2014. Of 31 continuously tested and initially MRSA CC398 positive participants only 8 (26%) were colonized with MRSA CC398at all 4 time points, 4 (13%) of them consistently with the same spa type. Among initially MRSA CC398 negative participants, 13 (7%) were tested MRSA CC398 positive at least once during the follow-up period. Data for household members at least at one time point were available for 185 households. Of these 21 (11%) households had one or more household member who tested positive for MRSA CC398at least once. The odds of household members to be MRSA CC398 positive was 12 times higher (95% confidence interval 4-37) when the conference participant tested MRSA CC398 positive in 2008/2009. This association remained strong when household members working in veterinary medicine or livestock farms were excluded. In summary, these data suggest that colonisation with MRSA CC398 is partially transient and that household members of MRSA CC398 colonized persons are at an increased risk of colonisation with MRSA CC398.

Topics: Adult; Animals; Bacterial Adhesion; Cohort Studies; Family; Female; Germany; Humans; Livestock; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prospective Studies; Staphylococcal Infections; Veterinarians

Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL) producing enterobacteria (ESBL-E) have emerged in livestock. This study prospectively investigates the prevalence of MRSA and ESBL-E on pig farms and in nasal and stool samples from farmers and compares molecular characteristics of these ESBL-E isolates. In 2014, samples were derived at 51 pig farms in Germany. Per farm, five dust and five fecal samples were collected; one nasal and one stool sample were retrieved from farmers. ESBL-E isolates from humans and environmental isolates from the respective farms were characterized using whole genome sequencing for classical multilocus sequence typing (MLST), determination of ESBL-encoding genes and an ad hoc core genome MLST (cgMLST) analysis. MRSA and ESBL-E were detected on 49 (96%) and 31 (61%) of the farms, respectively; in most cases (59%) simultaneously. Nasal MRSA carriage was detected in 72 of 85 (84.7%) farmers and five of 84 (6.0%) farmers carried ESBL-E. ESBL-Escherichia coli isolates from farmers belonged to MLST STs/ESBL-genes ST10/CTX-M-1, ST196/TEM-52, ST278/TEM-52, ST410/CTX-M-15 and ST453/CTX-M-1. In one case, the human ESBL-E isolate was clonally identical to isolates from the farm environment; in the other four cases typing results indicated potential exchange of resistance determinants between human and environmental isolates, but, comparing the isolates within a minimum spanning tree indicated differences in cgMLST-patterns between the farms (p=0.076). This study demonstrated rectal ESBL-E carriage rates among farmers, which were similar to those in the general population. Molecular typing suggested that cross-transmission between the farmers and the farm environment is possible.

Topics: Animals; Bacterial Typing Techniques; beta-Lactamases; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli; Farmers; Farms; Feces; Female; Germany; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multilocus Sequence Typing; Nose; Prospective Studies; Staphylococcal Infections; Swine; Swine Diseases

Nasal carriage of Staphylococcus aureus in diabetic patients may be a risk factor for diabetic foot lesion infections. The aims of this study were to compare the genotypic profiles of S. aureus strains isolated from nares and diabetic foot ulcers (DFUs) using microarray technology.. Patients were included if they were admitted for diabetic foot infection (DFI) at any of three diabetology departments of Montpellier and Nîmes University Hospitals between 1 September 2010 to 30 June 2012. All S. aureus isolates were analyzed using oligonucleotides arrays; S. aureus resistance and virulence genes were determined and each isolate was affiliated to a clonal complex.. The prevalence of S. aureus nasal carriage among the 276 included patients was 39.5% (n=109), while 36.6% (n=101) had S. aureus at both sites (nares and foot wounds) and, of these patients, 65.3% of patients harboured the same strain at both sites. In addition, the spread of the methicillin-resistant S. aureus (MRSA) ST398 clone in DFI and its tropism for bone were also further confirmed.. These findings appear to provide new arguments in favour of the systematic detection of nasal S. aureus carriage to anticipate the management of DFI.

Topics: Adult; Aged; Aged, 80 and over; Diabetic Foot; Female; Humans; Male; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Evidence suggests that diabetes might cause an increase in colonization of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in community settings. We carried out a cross-sectional study to determine the prevalence and influencing factors of S. aureus and MRSA nasal colonization among a community-based diabetes population, and to identify the characteristics of the isolated strains.. A total of 956 participants from 11 community settings were included in the study.. Of the 529 diabetes participants, 46 were colonized with S. aureus and 22 were colonized with MRSA. Of the 427 non-diabetes participants, 25 were colonized with S. aureus and 12 were colonized with MRSA. Men (odds ratio 0.45, 95% confidence interval 0.20-0.99, P = 0.047) were less likely to have S. aureus nasal colonization, and those with well-controlled blood glucose (odds ratio 2.04, 95% confidence interval 1.01-4.13, P = 0.047) among the diabetes population were more likely to have S. aureus nasal colonization. The proportion of multidrug-resistant S. aureus strains in the diabetes population (52.17%) was higher than that in the non-diabetes population (28.00%; χ. The prevalence of MRSA in the community-based diabetes population was moderate, and the high proportions of multidrug-resistant S. aureus strains and diverse molecular characteristics in the diabetes population should be noticed.

Topics: Aged; China; Cross-Sectional Studies; Diabetes Complications; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus

The coagulase enzyme, encoded by the coa gene, is an important virulence factor of Staphylococcus aureus and can be used for typing of S. aureus isolates. In this study, coa gene typing was used to study the epidemiology of S. aureus at a university hospital in Hamadān (Iran).. A total of 200 S. aureus strains were analysed, among which 150 were isolated from clinical samples and 50 were from nasal swab specimens of carriers. Methicillin resistance was confirmed by presence of the mecA gene by PCR. For polymorphism analysis, the coa gene was amplified by PCR and the products were subjected to restriction digestion using the enzyme AluI.. Amplification of the coa gene produced five classes of bands based on size, ranging from 300bp to 800bp. The 600-bp amplicon included coa 3 genotype predominated in S. aureus isolated from clinical and carrier specimens (150/200; 75.0%). AluI digestion of the PCR products produced eight distinct restriction fragment length polymorphism (RFLP) patterns, designated coa 1-8. The results showed that the 700-bp and 800-bp amplicons formed two (coa 4a and 4b) and three (coa 5a, 5b and 5c) patterns following AluI digestion, respectively, whereas the 300-, 500- and 600-bp fragments generated unique patterns designated coa 1, coa 2 and coa 3, respectively.. This study performed coagulase typing, a technique used to determine the molecular epidemiology of S. aureus clinical isolates. coa gene amplification has been considered a simple and accurate method for typing of S. aureus.

Topics: Bacterial Proteins; Bacterial Typing Techniques; Coagulase; DNA, Bacterial; Genes, Bacterial; Genetic Variation; Genotype; Hospitals; Humans; Iran; Methicillin; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Molecular Typing; Nose; Penicillin-Binding Proteins; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Staphylococcal Infections; Virulence Factors

To investigate the efficacy of a potent novel antimicrobial protein of mass 6 kDa, epidermicin NI01, for eradicating the nasal burden of MRSA in a cotton rat ( Sigmodon hispidus ) model.. MRSA strain ATCC 43300 was used to establish a robust colonization of cotton rat nares. This model was used to evaluate the efficacy of topical 0.04% and 0.2% epidermicin NI01, administered twice daily for 3 days consecutively, and topical 0.8% epidermicin NI01 administered once, for reducing nasal MRSA burden. Control groups remained untreated or were administered vehicle only (0.5% hydroxypropylmethylcellulose) or 2% mupirocin twice daily for 3 days. The experiment was terminated at day 5 and MRSA quantitative counts were determined. Tissues recovered from animals treated with 0.2% epidermicin twice daily for 3 days were examined for histological changes.. Mupirocin treatment resulted in a reduction in burden of log 10 (log R) of 2.59 cfu/nares compared with vehicle ( P  < 0.0001). Epidermicin NI01 administered once at 0.8% showed excellent efficacy, resulting in a log R of 2.10 cfu/nares ( P  = 0.0004), which was equivalent to mupirocin. Epidermicin NI01 administered at 0.2% or 0.04% twice daily for 3 days did not have a significant impact on the tissue burden recovered from the nares. Mild to marked histological abnormalities were noted, but these were determined to be reversible.. A single dose of topical epidermicin NI01 was as effective as mupirocin administered twice daily for 3 days in eradication of MRSA from the nares of cotton rats. This justifies further development of epidermicin for this indication.

Topics: Administration, Topical; Animals; Antimicrobial Cationic Peptides; Bacterial Load; Bacteriocins; Dose-Response Relationship, Drug; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Rats; Sigmodontinae; Staphylococcal Infections

Despite increasing antimicrobial resistance globally, data are lacking on prevalence and factors associated with Staphylococcus aureus (SA) and MRSA carriage in resource-limited settings.. To determine the prevalence of SA and MRSA nasal carriage and factors associated with carriage among Ugandan regional referral hospital patients.. We enrolled a cross-section of 500 adults, sampling anterior nares for SA and MRSA carriage using Cepheid Xpert SA Nasal Complete.. Mean age was 37 years; 321 (64%) were female and 166 (33%) were HIV infected. Overall, 316 (63%) reported risk factors for invasive SA infection; 368 (74%) reported current antibiotic use. SA was detected in 29% and MRSA in 2.8%. MRSA and MSSA carriers were less likely than SA non-carriers to be female (50% and 56% versus 68%, P  = 0.03) or to have recently used β-lactam antibiotics (43% and 65% versus 73%, P  = 0.01). MRSA carriers were more likely to have open wounds than MSSA carriers and SA non-carriers (71% versus 27% and 40%, P  = 0.001) and contact with pigs (21% versus 2% and 6%, P  = 0.008). MRSA carriage ranged from 0% of HIV clinic participants to 8% of inpatient surgical ward participants ( P  =   0.01). In multivariable logistic regression analysis, male sex was independently associated with SA carriage (OR 1.68, 95% CI 1.12-2.53, P  =   0.01) and recent β-lactam antibiotic use was associated with reduced odds of SA carriage (OR 0.61, 95% CI 0.38-0.97, P  =   0.04).. MRSA nasal carriage prevalence was low and associated with pig contact, open wounds and surgical ward admission, but not with HIV infection.

Topics: Adolescent; Adult; Carrier State; Female; HIV Infections; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nasal Cavity; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Uganda

MRSA emerged in livestock and persons in contact with livestock is referred to as livestock-associated MRSA (LA-MRSA). We assessed the prevalence and risk factors for MRSA carriage in persons not living or working on a farm.. A cross-sectional study was performed among 2492 adults living in close proximity of livestock farms. Persons working and/or living on farms were excluded. Nasal swabs were cultured using selective media. Participants completed questionnaires and the distance from the residential address to the nearest farm was calculated. The Mann-Whitney U -test was used to compare median distances. Risk factors were explored with logistic regression.. Fourteen persons carried MRSA (0.56%; 95% CI 0.32%-0.92%), 10 of which carried LA-MRSA of multiple-locus variable-number tandem repeat analysis complex (MC) 398 (0.40%; 95% CI 0.20%-0.71%). MRSA MC 398 carriers lived significantly closer to the nearest farm than non-carriers (median: 184 versus 402 m; P  <   0.01). In bivariate analyses correcting for contact with livestock, this difference remained significant.. Although the prevalence was low, living near farms increased the risk of MRSA MC 398 carriage for persons not living or working on a farm. Further research is necessary to identify the transmission routes.

Topics: Adult; Agriculture; Animals; Carrier State; Cross-Sectional Studies; Farms; Female; Humans; Livestock; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Surveys and Questionnaires

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is poorly described for surgeons, despite the increased exposure to nosocomial pathogens and at-risk patients. This study investigated the molecular epidemiology and antimicrobial resistance of 26 MRSA isolates cultured from the nares of an international cross-sectional study of 1166 human and 60 veterinary surgeons.. All isolates were subjected to agr, spa and multilocus sequence typing, and the presence of 22 virulence factors was screened for by PCR. Additionally, biofilm-forming ability, haemolytic activity, staphyloxanthin production and antibiotic resistance were determined. The genome of a rifampicin-resistant MRSA was sequenced.. Approximately half of the isolates belonged to well-described clonal lineages, ST1, ST5, ST8, ST45 and ST59, that have previously been associated with severe infections and increased patient mortality. Two of the three veterinarian MRSA belonged to epidemic livestock-associated MRSA clonal lineages (ST398 and ST8) previously associated with high transmission potential between animals and humans. The isolates did not display any consistent virulence gene pattern, and 35 % of the isolates carried at least one of the Panton-Valentine leukocidin (lukFS-PV), exfoliative toxin (eta) or toxic shock syndrome (tst) genes. Resistance to rifampicin was detected in one veterinarian isolate and was found to be due to three mutations in the rpoB gene.. Surgeons occupy a critical position in the healthcare profession due to their close contact with patients. In this study, surgeons were found to be colonized with MRSA at low rates, similar to those of the general population, and the colonizing strains were often common clonal lineages.

Topics: Bacterial Toxins; Biofilms; Cross Infection; Cross-Sectional Studies; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Female; Genome, Bacterial; Genotype; Humans; Internationality; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Multilocus Sequence Typing; Nose; Phenotype; Polymerase Chain Reaction; Rifampin; Sequence Analysis, DNA; Staphylococcal Infections; Surgeons; Veterinarians; Virulence Factors

Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

Topics: Bacterial Proteins; Bacterial Toxins; Exotoxins; Hand; Humans; Leukocidins; Methicillin-Resistant Staphylococcus aureus; Nose; Penicillin-Binding Proteins; Population Surveillance; Sputum; Staphylococcal Infections

Nasal carriage of Staphylococcus aureus among hospital personnel is a common cause of hospital acquired infections. Emergence of drug resistant strains especially methicillin resistant S. aureus (MRSA) is a serious problem in hospital environment. Therefore, the aim of this study was to determine the nasal carriage rate of S. aureus and MRSA among Health Care Workers (HCWs) at Al Shifa Hospital, the major hospital in Gaza Strip.. A cross sectional study was conducted on 200 HCWs. Nasal swabs were collected during February - April 2015, and cultured on blood and mannitol salt agar. The isolates were identified as S. aureus based on morphology, coagulase test, DNase test and mannitol salt agar fermentation. Disk diffusion antibiotic susceptibility tests were performed according to the guidelines of the Clinical and Laboratory Standards Institute. MRSA were confirmed by detection of the mecA gene by PCR.. Out of the 200 healthcare workers, 62 (31%) carried S. aureus, of which 51 (82.3%) were MRSA. Therefore, 25.5% of all HCWs were identified as MRSA carriers. MRSA carriage rate was highest among nurses (30.4%) whereas the carriage rate among doctors was (16%). The majority of MRSA carriers were workers of internal medicine department and surgical wards (41.3 and 35% respectively). Out of the 51 MRSA isolates identified by oxacillin disc resistance, 40 were confirmed by PCR targeting the mecA gene. Penicillin showed the highest rate of resistance among MRSA and MSSA isolates (100%).. The high rate of nasal MRSA carriage among healthcare workers found in this study is alarming and highlights the need for adjusted infection control measures to prevent MRSA transmission from HCWs to the vulnerable patient.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Carrier State; Cross Infection; Cross-Sectional Studies; Hospitals; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle East; Nose; Oxacillin; Penicillin-Binding Proteins; Personnel, Hospital; Polymerase Chain Reaction; Staphylococcal Infections

Variation in MRSA genotypes may affect the sensitivity of molecular assays to detect this organism.. We compared 2 commonly used screening assays, the Cepheid™ Xpert® MRSA and the BD MAX™ MRSA XT on consecutively obtained nasal swabs from 479 subjects. Specimens giving discordant results were subjected to additional microbiologic and molecular testing.. Six hundred forty-two (97.6%) of the 658 test results were concordant. Of the 16 discordant results from 12 subjects, additional results suggested that 9 (60%) of the 15 MRSA XT assays were likely correct, and 6 (40%) of the 15 Xpert® assays were likely correct. One discordant result could not be resolved. A mecA dropout and novel mec right-extremity junction (MREJ) sites led to false-positive and negative results by Xpert®.. While both assays performed well, continued vigilance is needed to monitor for Staphylococcus aureus with novel MREJ sites, mecA dropouts, and mecC, leading to inaccurate results in screening assays.

Topics: Bacterial Proteins; Bacteriological Techniques; Biological Assay; Humans; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Sensitivity and Specificity; Staphylococcal Infections

Livestock-associated Staphylococcus aureus (LA-SA) draws increasing attention due to its particular ability to colonize farm animals and be transmitted to people, which in turn leads to its spread in the environment. The aim of the study was to determine the dissemination of LA-SA on pig farms selected throughout Poland, characterize the population structure of identified S. aureus, and assess the prevalence of LA-SA carriage amongst farmers and veterinarians being in contact with pigs.. The study was conducted on 123 pig farms (89 farrow-to-finish and 34 nucleus herds), located in 15 out of 16 provinces of Poland. Human and pig nasal swabs, as well as dust samples were analyzed. S. aureus was detected on 79 (64.2%) farms from 14 provinces. Amongst these farms LA-SA-positive farms dominated (71/79, 89.9%, 95% CI [81.0%, 95.5%]). The prevalence of LA-MRSA-positive farms was lower than LA-MSSA-positive (36.6% of LA-SA-positive farms, 95% CI [25.5%, 48.9%] vs. 74.6%, 95% CI [62.9%, 84.2%]). In total, 190 S. aureus isolates were identified: 72 (38%) MRSA and 118 (62%) methicillin-susceptible S. aureus (MSSA), of which 174 (92%) isolates were classified to three livestock-associated lineages: CC398 (73%), CC9 (13%), and CC30/ST433 (6%). All CC398 isolates belonged to the animal clade. Four LA-MRSA clones were detected: ST433-IVa(2B) clone (n = 8, 11%), described to the best of our knowledge for the first time, and three ST398 clones (n = 64, 89%) with the most prevalent being ST398-V(5C2&5)c, followed by ST398-V(5C2), and ST398-IVa(2B). Nasal carriage of LA-SA by pig farmers was estimated at 13.2% (38/283), CC398 carriage at 12.7% (36/283) and ST398-MRSA carriage at 3.2% (9/283), whereas by veterinarians at 21.1% (8/38), 18.4% (7/38) and 10.5% (4/38), respectively.. The prevalence of LA-MRSA-positive pig farms in Poland has increased considerably since 2008, when the first MRSA EU baseline survey was conducted in Europe. On Polish pig farms CC398 of the animal clade predominates, this being also reflected in the prevalence of CC398 nasal carriage in farmers and veterinarians. However, finding a new ST433-IVa(2B) clone provides evidence for the continuing evolution of LA-MRSA and argues for further monitoring of S. aureus in farm animals.

Topics: Animals; Bacterial Proteins; Carrier State; DNA, Bacterial; Farmers; Farms; Geography; Humans; Livestock; Methicillin-Resistant Staphylococcus aureus; Multilocus Sequence Typing; Nose; Penicillin-Binding Proteins; Poland; Staphylococcal Infections; Swine

To compare the presence of Staphylococcus aureus and pathogenic Gram-negative rods (GNR) in the anterior nares, posterior pharynx and three skin sites in community-based adults and nursing home-based adults before and after treatment with nasal mupirocin and topical chlorhexidine.. S. aureus-colonized adults were recruited from the community (n=26) and from nursing homes (n=8). Eligible participants were cultured for S. aureus and GNR during two study visits and then received intranasal mupirocin and topical chlorhexidine for 5days, with a 2-month follow-up period.. After decolonization, we found sustained decreases of S. aureus colonization in nose, throat and skin sites over 4-8weeks in both populations. Intranasal mupirocin did not increase GNR colonization in nose or throat. Chlorhexidine did not decrease GNR colonization in skin sites.. Decolonization with mupirocin and chlorhexidine leads to a sustained effect on S. aureus colonization without affecting GNR colonization.

Topics: Administration, Topical; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Chlorhexidine; Community-Acquired Infections; Cross Infection; Female; Gram-Negative Bacterial Infections; Gram-Positive Asporogenous Rods; Humans; Male; Middle Aged; Mupirocin; Nose; Nursing Homes; Pharynx; Prospective Studies; Skin; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

The aim of this study was to assess the Staphylococcus aureus nasal carriage rate in healthy children all over Hungary and to specify some risk factors, the antibiotic resistance patterns of the bacteria, and their genetic relatedness. In total, 878 children (aged 3-6 years) were screened at 21 day-care centers in 16 different cities in Hungary, between February 2009 and December 2011. Samples taken from both nostrils were cultured on blood agar, and suspected S. aureus isolates were identified by β-hemolysis, catalase positivity, clump test, and nucA PCR. Methicillin-resistant strains were screened by mecA and mecC PCR. Antibiotic susceptibility was determined by agar dilution or gradient test strips. Pulsed-field gel electrophoresis was used for genotyping. S. aureus carriage rate was found to be 21.3%, which correlates well with international data. We found no statistically significant correlation between the gender or the sibling status and S. aureus carriage. All isolates were sensitive to oxacillin, trimethoprim-sulfamethoxazole, and mupirocin. The resistance rates for erythromycin, ciprofloxacin, clindamycin, gentamicin, and tetracycline were 7.5%, 0.5%, 1.1%, 3.7%, and 4.3%, respectively. The isolates showed very high genetic diversity. In summary, carried S. aureus isolates are more sensitive to antibiotics compared with clinical isolates in Hungary, and methicillin-resistant S. aureus carriage rate is very low yet.

Topics: Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Drug Resistance, Bacterial; Female; Genotype; Humans; Hungary; Male; Microbial Sensitivity Tests; Nose; Phylogeny; Staphylococcal Infections; Staphylococcus aureus

Biofilm production is an important virulence factor which allows staphylococci to adhere to medical devices. The principal component of biofilm is a "polysaccharide intercellular adhesin (PIA)" which is composed of a beta-1,6-N-acetylglucosamine polymer synthesized by an enzyme (N-acetylglucosamine transferase) encoded by the ica operon found on the bacterial chromosome. This operon is composed of four genes (A, B, C, and D), and a transposable element IS256. In this study, we aimed to determine the biofilm production characteristics of invasive/non-invasive staphylococcus isolates and different staphylococcus species. Biofilm production of 166 staphylococci was phenotypically investigated on Congo Red Agar (CRA); the presence of icaA, icaD and IS256 genes were investigated by polymerase chain reaction (PCR). 74 of the isolates (44.6%) were identified as methicillin resistant Staphylococcus aureus (MRSA), 25 (15.1%) as methicillin sensitive S.aureus (MSSA), 25 (37.3%) as Staphylococcus hominis, 20 (12%) as S.epidermidis, ten (15%) as Staphylococcus haemolyticus, nine (13.4%) as Staphylococcus capitis, two (3%) Staphylococcus saprophyticus and one (1.5%) as Staphylococcus warnerii. Of the MRSA strains, 52 were isolated from blood and 22 from nose; all MSSA strains were isolated from nose cultures. Coagulase-negative staphylococci (CoNS) strains were composed of invasive and non-invasive strains isolated from nose, catheter tip and blood cultures from patients with catheter. Production with CRA method was found to be statistically significant in invasive isolates (p< 0.001). It is concluded that; as the biofilm formation capacity of invasive isolates can cause refractory infections and the importance of carriage and hospital infections of these bacteria, it is important to prevent the spread of these isolates. A combination of phenotypic and genotypic tests is recommended for the investigation of biofilm formation in staphylococci. 40.3% of the CoNS isolates, and 85.8% of S.aureus isolates produced biofilm on CRA (p< 0.001) and with PCR method the ratio of carrying three genes was found to be statistically important in S.aureus when compared with CoNS. Carriage of three genes and biofilm formation capacity of invasive isolates can cause refractory infections and the importance of carriage and hospital infections of these bacteria, it is important to prevent the spread of these isolates. A combination of phenotypic and genotypic tests is recommended for the

Topics: Bacteremia; Biofilms; Carrier State; Catheters; Cross Infection; DNA Transposable Elements; Humans; N-Acetylglucosaminyltransferases; Nose; Operon; Polysaccharides, Bacterial; Staphylococcal Infections; Staphylococcus; Virulence

A history of methicillin-resistant Staphylococcus aureus (MRSA) is a determinant of inpatient bed assignment.. We assessed outcomes associated with rapid testing and discontinuation of MRSA contact precautions (CP) in a prospective cohort study of polymerase chain reaction (PCR)-based screening in the Emergency Department (ED) of Massachusetts General Hospital. Eligible patients had a history of MRSA and were assessed and enrolled if documented off antibiotics with activity against MRSA and screened for nasal colonization (subject visit). PCR-negative subjects had CP discontinued; the primary outcome was CP discontinuation. We identified semiprivate rooms in which a bed was vacant owing to the CP status of the study subject, calculated the hours of vacancy, and compared idle bed-hours by PCR results. Program costs were compared with predicted revenue.. There were 2864 eligible patients, and 648 (22.6%) subject visits were enrolled. Of these, 65.1% (422/648) were PCR-negative and had CP discontinued. PCR-negative subjects had fewer idle bed-hours compared with PCR-positive subjects (28.6 ± 25.2 vs 75.3 ± 70.5; P < .001). The expected revenues from occupied idle beds and averted CP costs ranged from $214,160 to $268,340, and exceeded the program costs.. A program of targeted PCR-based screening for clearance of MRSA colonization resulted in expected revenues and decreased CP costs that outweighed programmatic costs.

Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Cost-Benefit Analysis; Cross Infection; Female; Humans; Infection Control; Male; Massachusetts; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pilot Projects; Polymerase Chain Reaction; Prospective Studies; Staphylococcal Infections; Universal Precautions

We report the case of a soldier with recurrent skin infection associated with nasal carriage of a Panton-Valentine leukocidin (PVL)-producing methicillin-susceptible Staphylococcus aureus (MSSA), closely related to the EMRSA-15 clone. MSSA isolates causing infection not requiring hospitalization usually go unnoticed; however, their typing may be useful to understand the global distribution of successful staphylococcal lineages related to epidemic clones. PVL-positive MSSA strains might serve as reservoirs from which virulent methicillin-resistant strains may evolve and spread.

Topics: Adult; Bacterial Toxins; Carrier State; Exotoxins; Genotype; Humans; Leukocidins; Male; Military Personnel; Molecular Typing; Nose; Recurrence; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Virulence Factors

Most Staphylococcus aureus infections occur in previously colonized persons who also act as reservoirs for continued dissemination. This study aimed to investigate the carriage of antimicrobial resistance and virulence markers in S. aureus isolates associated with nasal colonization. The study was conducted from December 2013-April 2014. Nasal swabs were collected and questionnaires administered to 97 medical students in Riyadh Saudi Arabia. Bacterial culture, identification and antimicrobial susceptibility testing were performed by conventional methods and chromogenic agar was used for methicillin resistant S. aureus (MRSA) screening. Molecular characterization of isolates was carried out using the StaphyType DNA microarray. Thirty two students (43%) had S. aureus nasal carriage (MSSA = 31; MRSA = 1). Seventeen clonal complexes (CC) were identified namely: CC15-MSSA (n = 5), CC1-MSSA-SCCfus (n = 4), CC8-MSSA (n = 3), CC22-MSSA (n = 3), CC25-MSSA (n = 3), CC101-MSSA (n = 2). Other CC found as single isolates were CC5-MSSA, CC6-MSSA, CC30-MSSA, CC45-MSSA, CC96-MSSA, CC188-MSSA, CC398-MSSA, CC942-MSSA/PVL+, CC1290-MSSA, ST2482-MSSA, CC80-MRSA-IV/PVL+. The CC1-SCCfus isolates harbored the Staphylococcal cassette chromosome (SCC) with ccrA-1; ccrB-1 and ccrB-3 genes plus the putative fusidic acid resistance marker Q6GD50. One MSSA isolate was genotyped as coagulase negative Staphylococcus spp with an irregular composite SCCmec element. Majority of the isolates harbored various virulence genes including the hemolysin, enterotoxin, and exfoliative genes as well as various adhesive protein producing genes. Although there was low carriage of MRSA, the MSSA isolates harbored various resistance and virulence genes including those usually seen in MRSA isolates. The presence of isolates with incomplete SCCmec elements plus putative resistance and virulence genes is of concern.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Drug Resistance, Bacterial; Female; Genotype; Humans; Male; Methicillin; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

Staphylococcus aureus is a persistent companion bacterial species in one-third of humankind. Reservoirs include the nasal and nasopharyngeal cavities, skin, and gastrointestinal (GI) tract. Despite earlier claims that colonization of individuals is caused by clonal organisms, next-generation sequencing (NGS) has revealed that resident type heterogeneity is not exceptional. Carriage, whether overt or hidden, is correlated with a risk of autoinfection. In a recent article in mBio, it was shown that, based on staphylococcal genome sequencing, low-level GI persistence may cause long-term nosocomial outbreaks [L. Senn et al., 7(1):e02039-15, 2016, doi:10.1128/mBio.02039-15]. Institutional endemicity with methicillin-resistant S. aureus (MRSA) sequence type 228 (ST228) is shown to originate not from high-level nasal carriage or poor compliance with infection control practice but from low-grade asymptomatic GI colonization. This shows the power of NGS in elucidating staphylococcal epidemiology and, even more important, demonstrates that (drug-resistant) microorganisms may possess stealthy means of persistence. Identifying these persistence mechanisms is key to successful infection control.

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Disease Outbreaks; Drug Resistance, Bacterial; Genotype; High-Throughput Nucleotide Sequencing; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The hands and noses of food handlers colonized by Staphylococcus aureus are an important source of food contamination in restaurants and food processing. Several virulence factors can be carried by mobile elements in strains of S. aureus, including the immune evasion cluster (IEC). This gene cluster improves the capacity of S. aureus to evade the human immune response. Many studies have reported the transmission of strains between animals and humans, such as farm workers that have close contact with livestock. However, there are few studies on the transmission between food and food handlers. The aim of this study was to detect the IEC and the mecA gene in strains isolated from food handlers and to type these strains using the spa typing method. Thirty-five strains of S. aureus isolated from the noses and hands of food handlers in three different kitchens were analyzed for the presence of the mecA gene and IEC and by spa typing. All strains were negative for the mecA gene, and the presence of IEC was observed in 10 (28.6%) strains. Fifteen different spa types were observed, with the most frequent being t127 (42.85%) and t002 (11.42%). Strains from the two most prevalent spa types and a novel spa type were typed by multilocus sequence typing. spa types t127, t002, and t13335 were determined to be multilocus sequence types (ST) ST-30, ST-5, and ST-45, respectively. The food handlers may have been contaminated by these strains of S. aureus through food, which is suggested by the low frequency of IEC and by ST that are observed more commonly in animals.

Topics: Adult; Animals; Female; Food Handling; Hand; Humans; Immune Evasion; Male; Meat; Methicillin; Nose; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors; Workforce

In contrast to Staphylococcus aureus intermittent nasal carriers, persistent ones have the highest risk of infection. This study reports the usefulness of a simple nasal sampling algorithm to identify the S. aureus nasal carriage state of hemodialysis patients (HPs) and their subsequent risk of infection.From a cohort of 85 HPs, 76 were screened for S. aureus nasal carriage once a week during a 10-week period. The S. aureus nasal load was quantified by using either culture on chromogenic medium or fully automated real-time polymerase chain reaction assay. Molecular typing was used to compare strains from carriage and infection.The algorithm based on quantitative cultures was able to determine the status of S. aureus nasal carriage with a sensitivity of 95.8%, a specificity of 94.2%, a positive predictive value of 88.5%, and a negative predictive value of 98.0%. Of note, the determination of the S. aureus carriage state was obtained on the first nasal sample for all the 76 HPs, but 1 (98.7%). The algorithm based on quantitative polymerase chain reaction assay directly from the specimen yielded similar performances. During the 1-year follow-up after the last sampling episode, HPs classified as persistent nasal carriers with the algorithm were found to have a higher risk of S. aureus infection than those classified as nonpersistent carriers (P < 0.05), especially for infections of endogenous origin (P < 0.001).This simple algorithm is reliable for determining the S. aureus nasal carriage status in clinical practice and could contribute to characterize at an early stage of take-up patients with the highest risk of S. aureus infection.

Topics: Adult; Aged; Aged, 80 and over; Algorithms; Carrier State; Female; Humans; Male; Middle Aged; Nose; Prospective Studies; Renal Dialysis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Epidemiological data of methicillin resistant Staphylococcus aureus (MRSA) carriage in Indonesian hospitals are still scarce. These data are required for health management of infectious diseases in order to control hospital MRSA. The carriage rate of MRSA in nose and throat of patients on admission to Dr Soetomo Hospital Surabaya, Indonesia was 8.1% of 643 patients, 5.4% from throat, 3.9% from nose and 1.2% from both sites. Prevalence of MRSA among patients admitted to surgical and non-surgical ward was not different (8.2% and 8.0%, respectively). Although MRSA prevalence in Indonesian hospitals is low compared to many other countries worldwide, appropriate health strategies will be needed to be implemented if this infection is to be controlled.

Topics: Humans; Indonesia; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Admission; Pharynx; Prevalence; Risk Factors; Staphylococcal Infections

The anterior nares are regarded as the primary site for Staphylococcus aureus colonization, although studies have highlighted the potential importance of colonization at extra-nasal sites, including the oropharynx. Accordingly, the aims of this study were to assess the prevalence, persistence and molecular epidemiology of S. aureus colonization in the nares and oropharynx of Māori and Pacific children, a population with strikingly high rates of S. aureus infection.. A cross-sectional study of predominantly Māori and Pacific school-aged children in Auckland, New Zealand was performed in October 2013, and swabs were taken from the nares and oropharynx. Sampling was repeated from the same schools in October 2014. All S. aureus isolates underwent antimicrobial susceptibility testing and spa typing.. Overall, 506/893 (56.7%) children were colonized with S. aureus, and the colonization prevalence was significantly higher in the oropharynx than nares (41.1% vs. 31.5%; P < 0.001). Longitudinal colonization was significantly higher in the oropharynx than the nares, and children with longitudinal oropharyngeal colonization were more likely to be colonized with the same spa type than those colonized in the nares (67.6% vs. 37.0%; P = 0.01). Approximately 40% of children had discordant spa types at the nares and oropharynx.. Oropharyngeal S. aureus colonization represents a significant reservoir of S. aureus and it is possible that the oropharynx may represent a protected anatomical niche, enabling persistent colonization with the same S. aureus strain. Future study should attempt to better understand the determinants of oropharyngeal carriage.

Topics: Adolescent; Age Factors; Carrier State; Child; Child, Preschool; Cross-Sectional Studies; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; New Zealand; Nose; Oropharynx; Prevalence; Risk Factors; Schools; Staphylococcal Infections; Staphylococcus aureus

The main goal was to estimate the prevalence of methicillin-resistant Staphylococcus aureus on hands and in nose of health care professionals.. Detection of Staph. aureus on hands or in the nose of 169 individuals was performed. Nasal and hand carriage was found in 39·6 and in 8·9% respectively. About 17·2% of the individuals were carriers of methicillin-resistant Staph. aureus (MRSA) in the nose and 4·7% on hands. The majority of nasal MRSA were resistant to β-lactams, erythromycin and ciprofloxacin. All nasal MRSA were SCCmec type IV and Panton-Valentine leukocidin (PVL) negative. One MRSA isolated from hand was SCCmec type V. About 75·6% of MRSA isolates presented the same or closely related restriction patterns. Sixty per cent of Staph. aureus from hands and from noses from the same individual were the same strain.. MRSA nasal carriage was high considering healthy health care professionals but in accordance with high level of MRSA infection in Portugal. Isolates recovered in this study seemed to be different from major clones previously isolated in other Portuguese hospitals.. These findings may have implications on the knowledge of healthy health care workers as vehicles of MRSA infections among the community. Presence of several virulence factors may contribute to increased pathogenesis in case of infection.

Topics: Adult; Female; Hand; Health Personnel; Hospitals; Humans; Male; Methicillin Resistance; Nose; Portugal; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors; Young Adult

This study investigated colonization and association of staphylococci between healthy dogs and their owners. In a cross-sectional study, nasal carriage and antibiotic susceptibility of isolated staphylococci were determined for 119 dogs and 107 owners. Relatedness of the Staphylococcus isolates in dogs and their owners was investigated using antibiograms, toxin profiles, and genotyping by pulsed-field gel electrophoresis (PFGE), multilocus sequence type, and spa typing. Risk factors for carriage of methicillin-resistant staphylococci in dogs were also evaluated. Staphylococcus spp. were isolated from 65 (60.7%) owners and 44 (37.0%) dogs. The following species were isolated, listed in order of decreasing frequency: S. epidermidis, S. pseudintermedius, S. aureus, S. scheiferi subsp. coagulans, S. haemolyticus, S. sciuri, S. saprophyticus and S. warneri. S. pseudintermedius (65.9%) was the major isolate in dogs while S. epidermidis (81.5%) was the major type in owners. Among the isolates, 71.6% were methicillin resistant (MR) and 95.4% of the isolates demonstrated multi-drug resistance regardless of the origin. Only one dog-owner pair shared the same Staphylococcus spp. (S. pseudintermedius); however, the organisms were of different PFGE subtypes and exhibited different antibiotic resistance and toxin profiles while both isolates displayed same sequence type (ST365). While the dog-origin isolate showed spa type t02, the owner-origin isolate was negative to PCRs targeting spa gene sequence. Risk factor analysis showed that the presence of cohabitant animals was correlated with the nasal carriage of MR staphylococci in dogs. The cumulative data indicated that animal- and owner-origin staphylococci have various subtypes with high prevalence of MR; however, the bacteria are not shared between healthy dogs and their owners.

Topics: Adolescent; Adult; Aged; Animals; Anti-Bacterial Agents; Carrier State; Cross-Sectional Studies; Dog Diseases; Dogs; Drug Resistance, Multiple, Bacterial; Female; Genotype; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Republic of Korea; Risk Factors; Staphylococcal Infections; Staphylococcus; Young Adult

Community-associated methicillin-resistant Staphjlococcus aureus (CA-MRSA) strains appear to have rapidly disseminated among population in the community without established risk factors for MRSA worldwide. Panton-Valentine leukocidin (PVL) is a cytolytic toxin, encoded by the lukF-PV and lukF-PV genes. PVL may be the key toxin responsible for enhanced virulence of CA-MRSA. The aim of this study was to detect the genes encoding PVL in CA-MRSA isolates from healthy people from the District of Pomoravlje.. We took throat and nose swabs from healthy, employed persons with mandatory sanitary examinations and analyzed the presence of MRSA, between January 2011 and December 2012 in the District of Pomoravlje. Susceptibility of isolated strains to cefoxitin was investigated by using disc diffusion according to the recommendation of CLSI (Clinical Laboratory Standard Institute), and by E test. The presence of penicillin-binding protein 2a (PBP2a) in Stapbylococd was detected using latex agglutination Slidex@MRSA Detection test. The gold standard, polymerase chain reaction (PCR) assay, was used for detection of mecA gene and PVL gene, and typing of SCCmec region.. Our investigation showed that staphylococcal carrier state was present in 2.58% of 52,910 throat and nasal swabs, and in 50 of them (3.67%) MRSA was isolated. Among these MRSA, 2 (4/6) isolates were PVL-positive.. The prevalence of CA-MRSA and the presence of PVL gene among healthy, employed population in the District of Pomoravlje were low. The values obtained in this study show that, our region is not significantly different from the other parts of our country, nor from the other European countries.

Topics: Adolescent; Adult; Bacterial Toxins; Carrier State; Community-Acquired Infections; Exotoxins; Female; Healthy Volunteers; Humans; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Epidemiology; Nose; Pharynx; Polymerase Chain Reaction; Prevalence; Serbia; Staphylococcal Infections; Virulence Factors; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) infections are common among humans in Aboriginal communities in Canada, for unknown reasons.. Cross sectional study of humans and dogs in an Aboriginal community of approximately 1200 persons. Our objectives were to measure community-based prevalence of nasal MRSA colonization among humans, use multivariable logistic regression to analyze risk factors for MRSA colonization, and perform molecular typing of Staphylococci isolated to investigate interspecies transmission.. 461 humans were approached for consent and 442 provided complete data. 109/442 (24.7 %, 95 % C.I. = 20.7-28.7 %) of humans were colonized with MRSA. 169/442 (38.2 %) of humans had received antibiotics in the last 12 months. Only number of rooms in the house (OR 0.86, p = 0.023) and recreational dog use (OR 7.7, p = 0.002) were significant risk factors for MRSA colonization. 95/109 (87.1 %) of MRSA strains from humans were of the same spa type (CMRSA10/USA300). 8/157 (5.1 %, 95 % C.I. = 1.7-8.5 %) of dogs were colonized with methicillin-susceptible S. aureus, and no dogs were colonized with MRSA.. Human MRSA colonization in this community is very common, and a single clone is predominant, suggesting local transmission. Antibiotic use is also very common. Crowding may partially explain high colonization, but most considered risk factors including animal exposure were not predictive. Very few dogs carried human Staphylococcal strains.

Topics: Adult; Animals; Canada; Cross-Sectional Studies; Dog Diseases; Dogs; Ethnicity; Female; Humans; Indians, North American; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Typing; Nose; Prevalence; Risk Factors; Socioeconomic Factors; Staphylococcal Infections

Chlorhexidine and mupirocin have been increasingly used in healthcare facilities to eradicate methicillin-resistant Staphylococcus aureus (MRSA) carriage. The aim of this study was to determine the prevalence and mechanisms of chlorhexidine and mupirocin resistance in MRSA from invasive infections and colonisation. MRSA isolates obtained from blood and nasal samples between 2012 and 2014 were analysed. Susceptibility to mupirocin was determined by disk diffusion and Etest and susceptibility to chlorhexidine by broth microdilution. The presence of mupA and qac (A/B and C) genes was investigated by PCR. Molecular typing was performed in high-level mupirocin-resistant (HLMR) isolates. Mupirocin resistance was identified in 15.6% of blood isolates (10.9% HLMR) and 15.1% of nasal isolates (12.0% HLMR). Presence of the mupA gene was confirmed in all HLMR isolates. For blood isolates, chlorhexidine minimum inhibitory concentrations (MICs) ranged from ≤0.125 to 4mg/L and minimum bactericidal concentrations (MBCs) from ≤0.125 to 8mg/L. In nasal isolates, chlorhexidine MICs and MBCs ranged from ≤0.125 to 2mg/L. The qacA/B gene was detected in 2.2% of MRSA isolates (chlorhexidine MIC range 0.25-2mg/L) and the qacC gene in 8.2% (chlorhexidine MIC range ≤0.125-1mg/L). The prevalence of qacC was 18.9% in HLMR isolates and 3.6% in mupirocin-susceptible isolates (P=0.009). Most of the HLMR isolates (97.1%) belonged to ST125 clone. These results suggest that chlorhexidine has a higher potential to prevent infections caused by MRSA. In contrast, mupirocin treatment should be used cautiously to avoid the spread of HLMR MRSA.

Topics: Anti-Bacterial Agents; Bacteremia; Carrier State; Chlorhexidine; Drug Resistance, Bacterial; Genes, Bacterial; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Mupirocin; Nose; Spain; Staphylococcal Infections

MDR MRSA isolates cultured from primates, their facility and primate personnel from the Washington National Primate Research Center were characterized to determine whether they were epidemiologically related to each other and if they represented common local human-associated MRSA strains.. Human and primate nasal and composite environmental samples were collected, enriched and selected on medium supplemented with oxacillin and polymyxin B. Isolates were biochemically verified as Staphylococcus aureus and screened for the mecA gene. Selected isolates were characterized using SCCmec typing, MLST and WGS.. Nasal cultures were performed on 596 primates and 105 (17.6%) were MRSA positive. Two of 79 (2.5%) personnel and two of 56 (3.6%) composite primate environmental facility samples were MRSA positive. Three MRSA isolates from primates, one MRSA from personnel, two environmental MRSA and one primate MSSA were ST188 and were the same strain type by conventional typing methods. ST188 isolates were related to a 2007 ST188 human isolate from Hong Kong. Both MRSA isolates from out-of-state primates had a novel MLST type, ST3268, and an unrelated group. All isolates carried ≥1 other antibiotic resistance gene(s), including tet(38), the only tet gene identified.. ST188 is very rare in North America and has almost exclusively been identified in people from Pan-Asia, while ST3268 is a newly reported MRSA type. The data suggest that the primate MDR MRSA was unlikely to come from primate centre employees. Captive primates are likely to be an unappreciated source of MRSA.

Topics: Animals; Bacterial Proteins; Carrier State; Drug Resistance, Multiple, Bacterial; Environmental Microbiology; Genotype; Humans; Laboratory Personnel; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Penicillin-Binding Proteins; Primate Diseases; Primates; Staphylococcal Infections; United States

The vast majority of systemic bacterial infections are caused by facultative, often antibiotic-resistant, pathogens colonizing human body surfaces. Nasal carriage of Staphylococcus aureus predisposes to invasive infection, but the mechanisms that permit or interfere with pathogen colonization are largely unknown. Whereas soil microbes are known to compete by production of antibiotics, such processes have rarely been reported for human microbiota. We show that nasal Staphylococcus lugdunensis strains produce lugdunin, a novel thiazolidine-containing cyclic peptide antibiotic that prohibits colonization by S. aureus, and a rare example of a non-ribosomally synthesized bioactive compound from human-associated bacteria. Lugdunin is bactericidal against major pathogens, effective in animal models, and not prone to causing development of resistance in S. aureus. Notably, human nasal colonization by S. lugdunensis was associated with a significantly reduced S. aureus carriage rate, suggesting that lugdunin or lugdunin-producing commensal bacteria could be valuable for preventing staphylococcal infections. Moreover, human microbiota should be considered as a source for new antibiotics.

Topics: Animals; Anti-Bacterial Agents; Carrier State; Disease Models, Animal; Drug Resistance, Microbial; Female; Humans; Male; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Microbiota; Nose; Peptides, Cyclic; Sigmodontinae; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus lugdunensis; Symbiosis; Thiazolidines

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential approach for the control of MRSA colonization to minimize the-often occupational-exposure of humans. The aim of this study was to assess the efficacy of bacteriophage treatment on porcine nasal colonization with MRSA in vitro, in vivo, and ex vivo. The effectiveness of a bacteriophage combination of phage K*710 and P68 was assessed in vitro by incubating them with MRSA V0608892/1 (ST398) measuring the OD600 hourly. To study the in vivo effect, bacteriophages were administered in a gel developed for human application, which contain 109 plaque-forming units (pfu)/mL (K and P68 in a 19.25:1 ratio) for 5 days to piglets (N = 8) that were experimentally colonized with the MRSA strain. Eight piglets experimentally colonized were used as a negative control. The MRSA strain was also used to colonize porcine nasal mucosa explants and bacteriophages were applied to assess the ex vivo efficacy of treatment. Bacteriophages were effective in vitro. In vivo, sixteen piglets were colonized with MRSA but the number of CFU recovered after the application of the bacteriophages in 8 piglets was not reduced compared to the control animals (approx. 105 CFU/swab). In the ex vivo model, 108 CFU were used to establish colonization with MRSA; a reduction of colonization was not observed after application of bacteriophages. However, application of mupirocin both in vivo and ex vivo resulted in a near eradication of MRSA.. i) The MRSA strain was killed in the presence of the bacteriophages phage K*710 and P68 in vitro. ii) Bacteriophages did not reduce porcine nasal colonization in vivo or ex vivo. Physiological in vivo and ex vivo conditions may explain these observations. Efficacy in the ex vivo model matched that of the in vivo system.

Topics: Animals; Bacteriophages; Cells, Cultured; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nasal Mucosa; Nose; Staphylococcal Infections; Swine; Swine Diseases; Treatment Outcome

To evaluate the association between HIV and Staphylococcus aureus colonization after confounding by incarceration is removed.. A cross sectional stratified study of all HIV infected and a random sample of HIV-uninfected inmates from two maximum-security prisons in New York State. Structured interviews were conducted. Anterior nares and oropharyngeal samples were cultured and S. aureus isolates were characterized. Log-binomial regression was used to assess the association between HIV and S. aureus colonization of the anterior nares and/or oropharynx and exclusive oropharynx colonization. Differences in S. aureus strain diversity between HIV-infected and uninfected individuals were assessed using Simpson's Index of Diversity.. Among 117 HIV infected and 351 HIV uninfected individuals assessed, 47% were colonized with S. aureus and 6% were colonized with methicillin resistant S. aureus. The prevalence of S. aureus colonization did not differ by HIV status (PR = 0.99, 95% CI = 0.76-1.24). HIV infected inmates were less likely to be exclusively colonized in the oropharynx (PR = 0.55, 95% CI = 0.30-0.99). Spa types t571 and t064 were both more prevalent among HIV infected individuals, however, strain diversity was similar in HIV infected and uninfected inmates.. HIV infection was not associated with S. aureus colonization in these maximum-security prison populations, but was associated with decreased likelihood of oropharyngeal colonization. Factors that influence colonization site require further evaluation.

Topics: Adult; Carrier State; Cross-Sectional Studies; Female; Genetic Variation; HIV Infections; Humans; Interviews as Topic; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nasal Cavity; New York; Nose; Oropharynx; Prevalence; Prisons; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topical antimicrobials are often employed for decolonization and infection prevention and may alter the endogenous microbiota of the skin. The objective of this study was to compare the microbial communities and levels of richness and diversity in community-dwelling subjects and intensive care unit (ICU) patients before and after the use of topical decolonization protocols. We enrolled 15 adults at risk for Staphylococcus aureus infection. Community subjects (n = 8) underwent a 5-day decolonization protocol (twice daily intranasal mupirocin and daily dilute bleach-water baths), and ICU patients (n = 7) received daily chlorhexidine baths. Swab samples were collected from 5 anatomic sites immediately before and again after decolonization. A variety of culture media and incubation environments were used to recover bacteria and fungi; isolates were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Overall, 174 unique organisms were recovered. Unique communities of organisms were recovered from the community-dwelling and hospitalized cohorts. In the community-dwelling cohort, microbial richness and diversity did not differ significantly between collections across time points, although the number of body sites colonized with S. aureus decreased significantly over time (P = 0.004). Within the hospitalized cohort, richness and diversity decreased over time compared to those for the enrollment sampling (from enrollment to final sampling, P = 0.01 for both richness and diversity). Topical antimicrobials reduced the burden of S. aureus while preserving other components of the skin and nasal microbiota.

Topics: Adult; Aged; Anti-Bacterial Agents; Anti-Infective Agents, Local; Chlorhexidine; Cross Infection; Female; Humans; Intensive Care Units; Male; Microbiota; Middle Aged; Mupirocin; Nose; Skin; Sodium Hypochlorite; Staphylococcal Infections; Staphylococcus aureus

Biofilms are associated with persistent infections and resistant to conventional therapeutic strategies. The aim of this study was to investigate the quantity of biofilm produced on silicone intranasal splints.. Quantity of biofilm formation on silicone splints (SS) was tested on 15 strains of Staphylococcus aureus and Moraxella catarrhalis, respectively. Antimicrobial susceptibility testing was performed in accordance with European Committee on Antimicrobial Susceptibility Testing recommendations.. All tested strains formed different amounts of biofilm on SS: 66.7% S. aureus and 93.3% M. catarrhalis were weak biofilm producers and 33.3% S. aureus and 6.7% M. catarrhalis were moderate biofilm producers. S. aureus formed significantly higher quantity of biofilm compared with M. catarrhalis (p < 0.05). Multidrug resistant S. aureus produced significantly higher amount of biofilm compared with non-multidrug resistant strains (p < 0.05).. Quantity of biofilm on SS is highly dependent on bacterial species and their resistance patterns. Future studies are needed to ascertain another therapeutic option for prophylaxis prior to SS placement.

Topics: Anti-Bacterial Agents; Biofilms; Drug Resistance, Bacterial; Humans; Microbial Sensitivity Tests; Moraxella catarrhalis; Nose; Silicones; Splints; Staphylococcal Infections; Staphylococcus aureus

Studies in Australia and elsewhere have shown high levels of antibiotic resistance in coagulase-positive staphylococci in dogs visiting veterinary clinics with pyoderma and related conditions. Although important, such studies tend to overestimate the burden of resistance. The aim of the current study was to investigate the prevalence of coagulase-positive staphylococci in healthy dogs in Central Victoria to assess the level of antibiotic resistance among these isolates.. We recruited 117 healthy dogs into the study. Swabs were taken at four sites (ear, mouth, nose, perineum) and staphylococcal species identified and isolated using culture and biochemical techniques.. Staphylococcus pseudintermedius and S. aureus were recovered from 100 and 17 dogs, respectively; 15 dogs were simultaneously co-colonised with both organisms. The mouth and perineum were the most sensitive sites for recovery of these organisms. The most commonly encountered resistances were penicillin (95.2% and 72.4% in S. aureus and S. pseudintermedius, respectively) and doxycycline/tetracycline (19.7% in S. pseudintermedius). No methicillin-resistant S. aureus were recovered, but two phenotypically methicillin-resistant S. pseudintermedius (MRSP) isolates were recovered, although only one was PCR-positive for the mecA gene. Notably the MRSP isolate was multidrug resistant, as it also exhibited resistance to mupirocin and erythromycin.. With the exception of penicillin, doxycycline and tetracycline, the level of resistance to the antimicrobial agents tested was minimal. Prudent antibiotic use in treating companion animals with skin infections will reduce the selection of MRSP and other multidrug-resistant bacteria.

Topics: Animals; Anti-Bacterial Agents; Dogs; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Ear; Mouth; Nose; Perineum; Staphylococcal Infections; Staphylococcus; Victoria

Staphylococcus aureus (S aureus) decolonization regimens are being used to mitigate the risk of surgical site infection (SSI). However, their efficacy is controversial, with mixed results reported in the literature.. Before undergoing primary total knee arthroplasty (TKA), total hip arthroplasty (THA), or spinal fusion, 13,828 consecutive patients were screened for nasal S aureus and underwent a preoperative decolonization regimen. Infection rates of colonized and noncolonized patients were compared using unadjusted logistic regression. An adjusted regression analysis was performed to determine independent risk factors for SSI.. The rate of SSI in colonized patients was 4.35% compared with only 2.39% in noncolonized patients. In our TKA cohort, unadjusted logistic regression identified S aureus colonization to be a significant risk factor for SSI (odds ratio [OR], 2.9; P < 0.001). After controlling for other potential confounders including age, body mass index, tobacco use, and American Society of Anesthesiologists score, an SSI was 3.8 times more likely to develop in patients colonized with S aureus (OR, 3.8; P = 0.0025). The THA and spine colonized patients trended toward higher risk in both unadjusted and adjusted models; however, the results were not statistically significant.. The results of our study suggest that decolonization may not be fully protective against SSI. The risk of infection after decolonization is not lowered to the baseline of a noncolonized patient.. Level IV.

Topics: Adult; Aged; Anti-Infective Agents, Local; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Cross-Sectional Studies; Drug Therapy, Combination; Female; Humans; Logistic Models; Male; Middle Aged; Nose; Preoperative Care; Retrospective Studies; Risk Factors; Spinal Fusion; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Swine production work is a risk factor for nasal carriage of livestock-associated (LA-) Staphylococcus aureus and also for skin and soft tissue infection (SSTI). However, whether LA-S. aureus nasal carriage is associated with increased risk of SSTI remains unclear. We aimed to examine S. aureus nasal carriage and recent (≤3 months prior to enrollment) SSTI symptoms among industrial hog operation (IHO) workers and their household contacts. IHO workers and their household contacts provided a nasal swab and responded to a questionnaire assessing self-reported personal and occupational exposures and recent SSTI symptoms. Nasal swabs were analyzed for S. aureus, including methicillin-resistant S. aureus (MRSA), multidrug-resistant-S. aureus (MDRSA), absence of scn (livestock association), and spa type. S. aureus with at least one indicator of LA was observed among 19% of 103 IHO workers and 6% of 80 household members. Prevalence of recent SSTI was 6% among IHO workers and 11% among 54 minor household members (0/26 adult household members reported SSTI). Among IHO workers, nasal carriers of MDRSA and scn-negative S. aureus were 8.8 (95% CI: 1.8, 43.9) and 5.1 (95% CI: 1.2, 22.2) times as likely to report recent SSTI as non-carriers, respectively. In one household, both an IHO worker and child reported recent SSTI and carried the same S. aureus spa type (t4976) intranasally. Prevalence of scn-negative S. aureus (PR: 5.0, 95% CI: 1.2, 21.4) was elevated among IHO workers who reported never versus always wearing a face mask at work. Although few SSTI were reported, this study of IHO workers and their household contacts is the first to characterize a relation between nasal carriage of antibiotic-resistant LA-S. aureus and SSTI. The direction and temporality of this relation and IHO workers' use of face masks to prevent nasal carriage of these bacteria warrant further investigation.

Topics: Adult; Animals; Family Characteristics; Female; Humans; Industry; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Occupational Exposure; Prevalence; Risk Factors; Skin; Soft Tissue Infections; Staphylococcal Infections; Swine; Tetracycline

Bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) represent a well-known public health problem affecting both healthcare-associated and community populations. Past studies have clearly shown the value of characterizing problem organisms including MRSA through the use of molecular techniques (i.e. strain typing), with the aim of informing local, regional and national efforts in epidemiological analysis and infection control. The country of Libya represents a challenge for such analysis due to limited historical infectious disease information and major political unrest culminating in the Libyan Civil War (Libyan Revolution) in 2011. A MRSA study population of 202 isolates, cultured from patients in Tripoli Medical Center through this historical period (2008-2014), was characterized by both phenotypic and molecular methods. The results revealed a diversification of epidemic MRSA strains over time with generally increasing resistance to fluoroquinolone antibiotics. The study identified prevalent MRSA in comparison to known global epidemic types, providing unique insight into the change of strains and/or characteristics over time especially with reference to the potential influence of the political revolution (i.e. pre- and post-2011).

Topics: Anti-Bacterial Agents; Bacterial Typing Techniques; Cross Infection; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Fluoroquinolones; Humans; Infection Control; Libya; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Phenotype; Prevalence; Staphylococcal Infections

Staphylococcus aureus carriers are at higher risk of S. aureus infection and are a reservoir for transmission to others. Detection of nasal S. aureus carriage is important for both targeted decolonization and epidemiological studies. Self-administered nasal swabbing has been reported previously, but the effects of posting swabs prior to culture on S. aureus yield have not been investigated. A longitudinal cohort study was performed in which healthy volunteers were recruited, trained in the swabbing procedure and asked to take weekly nasal swabs for 6 weeks (median: 3 weeks, range 1-6 weeks). Two swabs were taken at each sampling episode and randomly assigned for immediate processing on arrival to the laboratory (Swab A) or second class postage prior to processing (Swab B). S. aureus was isolated using standard methods. A total of 95 participants were recruited, who took 944 swabs (472 pairs) over a median of 5 weeks. Of these, 459 swabs were positive for S. aureus. We found no significant difference (P=0.25) between 472 pairs of nasal self-swabs processed immediately or following standard postage from 95 study participants (51.4 % vs. 48.6 %, respectively). We also provide further evidence that persistent carriers can be detected by two weekly swabs with high degrees of sensitivity [92.3 % (95 % CI 74.8-98.8 %)] and specificity [95.6 % (95 % CI 84.8-99.3 %)] compared with a gold standard of five weekly swabs. Self-swabbing and postage of nasal swabs prior to processing has no effect on yield of S. aureus, and could facilitate large community-based carriage studies.

Topics: Adolescent; Adult; Aged; Carrier State; Cohort Studies; Female; Healthy Volunteers; Humans; Longitudinal Studies; Male; Middle Aged; Nose; Postal Service; Self Administration; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Staphylococci are a major constituent of the nasal microbiome and a frequent cause of hospital-acquired infection. Antibiotic surgical prophylaxis is administered prior to surgery to reduce a patient's risk of postoperative infection. The impact of surgical prophylaxis on the nasal staphylococcal microbiome is largely unknown. Here, we report the species present in the nasal staphylococcal microbiome and the impact of surgical prophylaxis revealed by a novel culture independent technique. Daily nasal samples from 18 hospitalised patients, six of whom received no antibiotics and 12 of whom received antibiotic surgical prophylaxis (flucloxacillin and gentamicin or teicoplanin +/- gentamicin), were analysed by tuf gene fragment amplicon sequencing.. On admission to hospital, the species diversity of the nasal staphylococcal microbiome varied from patient to patient ranging from 4 to 10 species. Administration of surgical prophylaxis did not substantially alter the diversity of the staphylococcal species present in the nose; however, surgical prophylaxis did impact on the relative abundance of the staphylococcal species present. The dominant staphylococcal species present in all patients on admission was Staphylococcus epidermidis, and antibiotic administration resulted in an increase in species relative abundance. Following surgical prophylaxis, a reduction in the abundance of Staphylococcus aureus was observed in carriers, but not a complete eradication.. Utilising the tuf gene fragment has enabled a detailed study of the staphylococcal microbiome in the nose and highlights that although there is no change in the heterogeneity of species present, there are changes in abundance. The sensitivity of the methodology has revealed that the abundance of S. aureus is reduced to a low level by surgical prophylaxis and therefore reduces the potential risk of infection following surgery but also highlights that S. aureus does persist.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Antibiotic Prophylaxis; Bacterial Proteins; Female; Floxacillin; Gentamicins; High-Throughput Nucleotide Sequencing; Humans; Male; Middle Aged; Nose; Peptide Elongation Factor Tu; Phylogeny; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus; Teicoplanin

During the last decades, healthcare-associated genotypes of methicillin-resistant Staphylococcus epidermidis (HA-MRSE) have been established as important opportunistic pathogens. However, data on potential reservoirs on HA-MRSE is limited. The aim of the present study was to investigate the dynamics and to which extent HA-MRSE genotypes colonize patients, healthcare workers (HCWs) and the environment in an intensive care unit (ICU).. Over 12 months in 2006-2007, swab samples were obtained from patients admitted directly from the community to the ICU and patients transferred from a referral hospital, as well as from HCWs, and the ICU environment. Patients were sampled every third day during hospitalization. Antibiotic susceptibility testing was performed according to EUCAST guidelines. Pulsed-field gel electrophoresis and multilocus sequence typing were used to determine the genetic relatedness of a subset of MRSE isolates.. We identified 620 MRSE isolates from 570 cultures obtained from 37 HCWs, 14 patients, and 14 environmental surfaces in the ICU. HA-MRSE genotypes were identified at admission in only one of the nine patients admitted directly from the community, of which the majority subsequently were colonized by HA-MRSE genotypes within 3 days during hospitalization. Almost all (89%) of HCWs were nasal carriers of HA-MRSE genotypes. Similarly, a significant proportion of patients transferred from the referral hospital and fomites in the ICU were widely colonized with HA-MRSE genotypes.. Patients transferred from a referral hospital, HCWs, and the hospital environment serve as important reservoirs for HA-MRSE. These observations highlight the need for implementation of effective infection prevention and control measures aiming at reducing HA-MRSE transmission in the healthcare setting.

Topics: Aged; Aged, 80 and over; Cross Infection; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Health Personnel; Hospitals; Humans; Intensive Care Units; Male; Methicillin Resistance; Middle Aged; Multilocus Sequence Typing; Nose; Patients; Prospective Studies; Staphylococcal Infections; Staphylococcus epidermidis; Sweden

Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus.. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010.. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04).. In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group.

Topics: Aged; Anti-Bacterial Agents; Anti-Infective Agents, Local; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Carrier State; Chlorhexidine; Female; Humans; Incidence; Male; Mupirocin; Nose; Prosthesis-Related Infections; Staphylococcal Infections; Staphylococcus aureus

This study aimed to evaluate the persistence of nasal carriage of Staphylococcus aureus, methicillin-resistant S. aureus and multidrug-resistant S. aureus over 14 days of follow-up among industrial hog operation workers in North Carolina.. Workers anticipating at least 24 h away from work were enrolled June-August 2012. Participants self-collected a nasal swab and completed a study journal on the evening of day 1, and each morning and evening on days 2-7 and 14 of the study. S. aureus isolated from nasal swabs were assessed for antibiotic susceptibility, spa type and absence of the scn gene. Livestock association was defined by absence of scn.. Twenty-two workers provided 327 samples. S. aureus carriage end points did not change with time away from work (mean 49 h; range >0-96 h). Ten workers were persistent and six were intermittent carriers of livestock-associated S. aureus. Six workers were persistent and three intermittent carriers of livestock-associated multidrug-resistant S. aureus. One worker persistently carried livestock-associated methicillin-resistant S. aureus. Six workers were non-carriers of livestock-associated S. aureus. Eighty-two per cent of livestock-associated S. aureus demonstrated resistance to tetracycline. A majority of livestock-associated S. aureus isolates (n=169) were CC398 (68%) while 31% were CC9. No CC398 and one CC9 isolate was detected among scn-positive isolates.. Nasal carriage of livestock-associated S. aureus, multidrug-resistant S. aureus and methicillin-resistant S. aureus can persist among industrial hog operation workers over a 14-day period, which included up to 96 h away from work.

Topics: Adult; Animal Husbandry; Animals; Anti-Bacterial Agents; Carrier State; Drug Resistance, Multiple, Bacterial; Female; Genes, Bacterial; Humans; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; North Carolina; Nose; Occupational Diseases; Occupational Exposure; Staphylococcal Infections; Staphylococcus aureus; Swine; Tetracycline; Young Adult

To evaluate nasal carriage rate and variables associated with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted in two healthcare facilities.. S. aureus was isolated from 159 (26%) of the enrolled patients. Methicillin-susceptible S. aureus was isolated from 150 (24.5%) patients, and MRSA was isolated from 9 (1.5%). Cancer and previous hospitalization were associated with a significantly higher frequency of nasal S. aureus carriage among the patients admitted to the general hospital and the nephrology department, respectively. MRSA isolates were heterogeneous with respect to their staphylococcal cassette chromosome mec element (SCCmec) type, sequence type (ST), and toxin genes (pvl and tst1) content. Four isolates were attributed with the ST80-MRSA-IV clone, which is known to be predominant in Algeria.. This is the first assessment of S. aureus and MRSA nasal carriage and associated variables in Algeria. Our findings provide also a picture of the MRSA strains circulating in the community in this geographic area. They can be useful as a guide for implementing screening and control procedures against S. aureus/MRSA in the Algerian healthcare facilities.

Topics: Adult; Aged; Algeria; Female; Genes, Bacterial; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Staphylococcal Infections

Previous research on Staphylococcus aureus in pigs focused on livestock-associated methicillin-resistant S. aureus (MRSA) and had a qualitative cross-sectional design. This study aimed to elucidate the frequency, load, and stability of S. aureus nasal carriage in pigs over time and investigated possible associations between carriage and immune response. Nasal swabs were collected three times weekly from 480 tagged adult pigs in 20 Danish production farms. S. aureus and MRSA were quantified on selective media by the most-probable-number method. The levels of IgG against 10 S. aureus antigens in serum were quantified in selected pigs by a Luminex assay. All the farms were positive for S. aureus and 15 for MRSA, leading to overall prevalences of persistent and intermittent carriers and noncarriers of 24, 52, and 23%, respectively. Carriage frequency and nasal loads were significantly higher on MRSA-positive farms. Logistic-regression modeling revealed the presence of individual pigs characterized by high nasal loads (>10,000 CFU per swab) and stable carriage regardless of farm- and pen-associated factors. On the other hand, the humoral response was strongly influenced by these environmental factors. The existence of a minority of shedders contributing to maintenance of S. aureus within farms opens up new perspectives on the control of MRSA in pig farming.

Topics: Animals; Antibodies, Bacterial; Carrier State; Disease Susceptibility; Female; Male; Methicillin-Resistant Staphylococcus aureus; Nasal Mucosa; Nose; Staphylococcal Infections; Sus scrofa; Swine; Swine Diseases

We compared the standard procedure of three MRSA follow-up culture sets to six to determine the number of recurrences detected between the third and sixth follow-up culture-set, and studied possible risk factors for MRSA recurrence.. A retrospective carrier cohort (2005-2010) was studied. Data was collected on MRSA culture-sets, follow-up, risk factors and outcome (recurrences during follow-up). We compared outcome between three and six follow-up MRSA culture sets, between HCWs and patients groups for complicated or uncomplicated carriers, and between nose-throat carriers and other carriers.. Of 406 MRSA carriers, 179 had received eradication therapy and had a negative first follow-up MRSA culture-set. Between the third and sixth follow-up culture-set 54% (35/65) of total recurrences occurred. Over 88% of all recurrences were detected within two months. Combined nose and throat carriage OR 25.5 (1.6-419.1)) and intravascular lines (OR 13.6 (1.2-156.2)) were risk factors for early recurrence.. We recommend five culture-sets till one year after successful eradication therapy with a distinction between those at risk for early recurrence and HCWs who require frequent culturing in the beginning and those not at risk for early recurrence. This recommendation is a balance between the need for swift detection of MRSA recurrence and the patients' burden.

Topics: Adult; Anti-Bacterial Agents; Carrier State; Follow-Up Studies; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Recurrence; Retrospective Studies; Risk Factors; Staphylococcal Infections; Time Factors

OBJECTIVE To explore the economic impact to a hospital of universal methicillin-resistant Staphylococcus aureus (MRSA) screening. METHODS We used a decision tree model to estimate the direct economic impact to an individual hospital of starting universal MRSA screening and contact precautions. Projected costs and benefits were based on literature-derived data. Our model examined outcomes of several strategies including non-nares MRSA screening and comparison of culture versus polymerase chain reaction-based screening. RESULTS Under baseline conditions, the costs of universal MRSA screening and contact precautions outweighed the projected benefits generated by preventing MRSA-related infections, resulting in economic costs of $104,000 per 10,000 admissions (95% CI, $83,000-$126,000). Cost-savings occurred only when the model used estimates at the extremes of our key parameters. Non-nares screening and polymerase chain reaction-based testing, both of which identified more MRSA-colonized persons, resulted in more MRSA infections averted but increased economic costs of the screening program. CONCLUSIONS We found that universal MRSA screening, although providing potential benefit in preventing MRSA infection, is relatively costly and may be economically burdensome for a hospital. Policy makers should consider the economic burden of MRSA screening and contact precautions in relation to other interventions when choosing programs to improve patient safety and outcomes.

Topics: Carrier State; Colony Count, Microbial; Cost-Benefit Analysis; Cross Infection; Hospital Costs; Humans; Infection Control; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Oropharynx; Polymerase Chain Reaction; Staphylococcal Infections

OBJECTIVE Nasal swab culture is the standard method for identifying methicillin-resistant Staphylococcus aureus (MRSA) carriers. However, this method is known to miss a substantial portion of those carrying MRSA elsewhere. We hypothesized that the additional use of a sponge to collect skin culture samples would significantly improve the sensitivity of MRSA detection. DESIGN Hospitalized patients with recent MRSA infection were enrolled and underwent MRSA screening of the forehead, nostrils, pharynx, axilla, and groin with separate swabs and the forehead, axilla, and groin with separate sponges. Staphylococcal cassette chromosome mec (SCCmec) typing was conducted by polymerase chain reaction (PCR). PATIENTS A total of 105 MRSA patients were included in the study. RESULTS At least 1 specimen from 56.2% of the patients grew MRSA. Among patients with at least 1 positive specimen, the detection sensitivities were 79.7% for the swabs and 64.4% for the sponges. Notably, 86.4% were detected by a combination of sponges and nasal swab, and 72.9% were detected by a combination of pharyngeal and nasal swabs, whereas only 50.9% were detected by nasal swab alone (P<0.0001 and P=0.0003, respectively). Most isolates had SCCmec type II (59.9%) and IV (35.7%). No correlation was observed between the SCCmec types and collection sites. CONCLUSION Screening using a sponge significantly improves MRSA detection when used in addition to screening with the standard nasal swab.

Topics: Adult; Aged; Aged, 80 and over; Axilla; Carrier State; Female; Forehead; Groin; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Typing; Nose; Pharynx; Polymerase Chain Reaction; Sensitivity and Specificity; Skin; Staphylococcal Infections; Surgical Sponges; Young Adult

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Drug Resistance, Multiple, Bacterial; Hospitals, Veterans; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Mupirocin; Nose; Population Surveillance; Staphylococcal Infections; Surgical Wound Infection

Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment.. We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa-typing, and antibiotic susceptibility was tested.. Nineteen (63%) of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26%) S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37%) patients were distributed over two different MLVF clusters. Wounds of three (16%) patients were colonized with isolates belonging to two different genotypes at the same time, and five (26%) patients were colonized with different S. aureus types over time. Five (17%) of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA).. The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

Topics: Adult; Bacterial Typing Techniques; Buruli Ulcer; Coinfection; Female; Genetic Variation; Ghana; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Minisatellite Repeats; Mycobacterium ulcerans; Nose; Staphylococcal Infections

Persons living with HIV (PLWH) are disproportionately burdened with methicillin-resistant Staphylococcus aureus (MRSA). Our objective was to evaluate prevalence and risks for MRSA colonization in PLWH.. Adults were recruited from Johns Hopkins University AIDS Service in Baltimore, Maryland. A risk questionnaire and specimen collection from anatomic sites with culture susceptibility and genotyping were completed. Generalized estimating equation modeling identified MRSA colonization risk factors.. Of 500 participants, most were black (69%), on antiretroviral therapy (ART) (87%), with undetectable viral loads (73.4%). Median CD4 count was 487 cells/mm(3) (interquartile range, 316-676.5 cells/mm(3)). MRSA prevalence was 15.4%, predominantly from the nares (59.7%). Forty percent were nares negative but were colonized elsewhere. Lower odds for colonization were associated with recent sexual activity (adjusted odds ratio [AOR] = 0.84, P < .001) and ART (AOR = 0.85, P = .011). Increased odds were associated with lower income (<$25,000 vs >$75,000; AOR = 2.68, P < .001), recent hospitalization (AOR = 1.54, P < .001), incarceration (AOR = 1.55, P < .001), use of street drugs (AOR = 1.43, P < .001), and skin abscess (AOR = 1.19, P < .001).. Even with high MRSA prevalence, the proportion identified through nares surveillance alone was low, indicating the importance of screening multiple anatomic sites. Associations were not found with same-sex coupling or black race. MRSA prevention might be a benefit of ART in PLWH.

Topics: Adult; Anti-Retroviral Agents; Antiretroviral Therapy, Highly Active; Baltimore; CD4 Lymphocyte Count; Cohort Studies; Cross-Sectional Studies; Female; HIV Infections; Hospitalization; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Risk Factors; Socioeconomic Factors; Specimen Handling; Staphylococcal Infections; Surveys and Questionnaires; Viral Load

A total of 261 healthy farm and pet animals (75 cattle, 52 goats, 100 dogs, and 34 cats) from different regions of Tunisia were screened for Staphylococcus aureus nasal carriage. Molecular typing of isolates (by spa- and multilocus sequence-typing) was performed, and their antimicrobial resistance and virulence genotypes were determined by PCR and sequencing. S. aureus isolates were detected in 17 of 261 tested samples (6.5%). All S. aureus isolates recovered were methicillin-susceptible (MSSA), and one isolate/sample was further studied. Eight different spa types were detected (t189, t279, t582, t701, t1166, t1268, t1534, and t1773), and eight different sequence types were identified (ST6, ST15, ST45, ST133, ST188, ST700 [clonal complex CC130], ST2057, and a new ST2121). MSSA from pets (six isolates) showed resistance to (number of isolates, resistance gene): penicillin (six, blaZ), tetracycline (one, tet[M]), erythromycin one, erm[A]), streptomycin (one, ant[6]-Ia), and ciprofloxacin (one). All isolates from farm animals showed susceptibility to the tested antimicrobials, except for two penicillin-resistant isolates. Five S. aureus isolates from goats and cats harbored the lukF/lukS-PV genes, encoding the Panton-Valentine leukocidin, and six isolates from goats harbored the tst virulence gene. In addition, diverse combinations of enterotoxin genes were detected, including two variants of the egc cluster. Goats and cats could represent a reservoir of important toxin genes, with potential implications in animal and human health.

Topics: Animals; Animals, Domestic; Anti-Bacterial Agents; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Cats; Cattle; Dogs; Exotoxins; Goats; Humans; Leukocidins; Methicillin; Multilocus Sequence Typing; Nose; Penicillins; Pets; Staphylococcal Infections; Staphylococcus aureus; Tetracycline; Tunisia; Virulence Factors

Large outbreaks of Staphylococcus aureus (SA) infections have occurred in correctional facilities across the country. We aimed to define the epidemiological and microbiological determinants of SA infection in prisons to facilitate development of prevention strategies for this underserved population.. We conducted a case-control study of SA infection at 2 New York State maximum security prisons. SA-infected inmates were matched with 3 uninfected controls. Subjects had cultures taken from sites of infection and colonization (nose and throat) and were interviewed via structured questionnaire. SA isolates were characterized by spa typing. Bivariate and multivariable analyses were conducted using conditional logistic regression.. Between March 2011 and January 2013, 82 cases were enrolled and matched with 246 controls. On bivariate analysis, the use of oral and topical antibiotics over the preceding 6 months was strongly associated with clinical infection (OR, 2.52; P < .001 and 4.38, P < .001, respectively). Inmates with clinical infection had 3.16 times the odds of being diabetic compared with inmates who did not have clinical infection (P < .001). Concurrent nasal and/or oropharyngeal colonization was also associated with an increased odds of infection (OR, 1.46; P = .002). Among colonized inmates, cases were significantly more likely to carry the SA clone spa t008 (usually representing the epidemic strain USA300) compared to controls (OR, 2.52; P = .01).. Several inmate characteristics were strongly associated with SA infection in the prison setting. Although many of these factors were likely present prior to incarceration, they may help medical staff identify prisoners for targeted prevention strategies.

Topics: Adolescent; Adult; Aged; Carrier State; Case-Control Studies; Disease Outbreaks; Female; Humans; Male; Middle Aged; New York; Nose; Oropharynx; Prevalence; Prisoners; Prisons; Regression Analysis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires; Time Factors; Young Adult

Topics: Anti-Bacterial Agents; Arthroplasty, Replacement, Knee; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Preoperative Care; Staphylococcal Infections; Surgical Wound Infection; Treatment Outcome

Reducing the spread of multidrug-resistant bacteria in hospitals remains a challenge. Current methods are screening of patients, isolation, and adherence to hygiene measures among healthcare workers (HCWs). More specific measures could rely on a better characterization of the contacts at risk of dissemination.. To quantify how close-proximity interactions (CPIs) affected Staphylococcus aureus dissemination. DESIGN Nested case-control study.. French long-term care facility in 2009.. Patients (n=329) and HCWs (n=261).. We recorded CPIs using electronic devices together with S. aureus nasal carriage during 4 months in all participants. Cases consisted of patients showing incident S. aureus colonization and were paired to 8 control patients who did not exhibit incident colonization at the same date. Conditional logistic regression was used to quantify associations between incidence and exposure to demographic, network, and carriage covariables.. The local structure of contacts informed on methicillin-resistant S. aureus (MRSA) carriage acquisition: CPIs with more HCWs were associated with incident MRSA colonization in patients (odds ratio [OR], 1.10 [95% CI, 1.04-1.17] for 1 more HCW), as well as longer CPI durations (1.03 [1.01-1.06] for a 1-hour increase). Joint analysis of carriage and contacts showed increased carriage acquisition in case of CPI with another colonized individual (OR, 1.55 [1.14-2.11] for 1 more HCW). Global network measurements did not capture associations between contacts and carriage.. Electronically recorded CPIs inform on the risk of MRSA carriage, warranting more study of in-hospital contact networks to design targeted intervention strategies.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Case-Control Studies; Cross Infection; Female; Humans; Incidence; Infectious Disease Transmission, Patient-to-Professional; Infectious Disease Transmission, Professional-to-Patient; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Rehabilitation Centers; Risk Factors; Staphylococcal Infections; Time Factors; Wireless Technology; Young Adult

To study the relationship between nasal carriage and Staphylococcus aureus (S. aureus) infection in hospitalized children.. Fifty-six hospitalized children infected with S. aureus were recruited in this study. Nasal swabs were collected and cultured, and the nasal carriage rate of S. aureus was examined. PVL virulence gene and mecA resistance gene were both detected in clinical strains and nasal carriage strains by PCR.. Twenty-two (39%) of the 56 children had nasal carriage of S. aureus, and most of them (18 cases) were younger than one year. Among these 22 children, 11 (50%) had previous hospitalization over the past year. In the infected strains, the rate of methicillin-resistant S. aureus (MRSA) was 29% (16/56), while it was 32% (7/22) in carriage strains. The mecA positive results in clinical strains were consistent with the results in nasal carriage strains. Among 5 PVL-positive nasal carriage strains, 4 (90%) could be matched with their clinical strains, all of which were MRSA.. Nasal carriage is a potential risk factor for S. aureus infection. Nosocomial transmission may lead to nasal carriage, which can cause S. aureus infection. The isolation rate of MRSA is high in hospitalized children infected with S. aureus, which implies that more attention is needed for this situation. The isolates from noses may be clonally identical to the isolates from clinical secretions, and the homology between them needs to be confirmed by multi-locus sequence typing.

Topics: Bacterial Proteins; Carrier State; Child; Child, Hospitalized; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Penicillin-Binding Proteins; Staphylococcal Infections; Staphylococcus aureus

To study the nasal carriage rate of Staphylococcus aureus (S. aureus) (including methicillin-resistant strains) in secondary school community of the urban and rural districts of the Kurdistan region of Iraq, a cross-sectional population based survey was carried out in the city Duhok and rural areas of Amedya, Akre and Zakho.. Nasal swabs were obtained from nostrils of 509 students aged 14-23 years. Resistance to methicillin was assessed by Kirby-Bauer disk diffusion and agar dilution assay. Vancomycin sensitivity was also tested on Muller-Hinton agar.. It was found that the frequency of overall S. aureus nasal carriage (SANC) was 17.75% (90/509, CI95, 14.58-21.42%). In urban areas, the carriage rate was 20.59% (49/239, CI95, 15.64-26.29%), whereas it was 15.24% (41/270, CI95, 11.17-20.10%) in rural districts. The frequency of methicillin-resistant S. aureus (MRSA) among the isolated strains was found to be 2.04% (1/49) and 21.95% (9/41) in urban and rural areas respectively. It was found that in urban residents, the odd ratio (OR) of acquiring SANC was 1.44 (CI95, 0.91-2.27%) and risk ratio (RR) was at least 1.35 (CI95, 0.92-1.96%) while OR decreased to 0.12 (CI95, 0.01-0.96%) for MRSA carriage. Hence, the S. aureus carriage rate was higher in urban districts compared to rural areas while more MRSA were found in rural areas compared to urban districts. All studied strains were sensitive to vancomycin.. This study provided baseline information for S. aureus nasal colonization in the region. Also, it showed that living in rural areas increased the odds of MRSA colonization. More attention should be paid to control MRSA colonization in rural communities.

Topics: Adolescent; Age Distribution; Colony Count, Microbial; Female; Humans; Iraq; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Residence Characteristics; Rural Population; Schools; Staphylococcal Infections; Urban Population; Young Adult

Wound occurrence (WO) after major lower extremity amputation (MLEA) can be due to wound infection or sterile dehiscence. We sought to determine the association of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and other patient factors with overall WO, WO due to wound infection, and WO due to sterile dehiscence.. The medical records of all patients undergoing MLEA from August 1, 2011, to November 1, 2013, were reviewed. Demographic data, hemoglobin A1c level, albumin concentration, dialysis dependence, peripheral vascular disease (PVD), nasal MRSA colonization, and diabetes mellitus (DM) were examined as variables. The overall WO rate was determined, and the cause of WO was categorized as either a sterile dehiscence or a wound infection.. Eighty-three patients underwent 96 MLEAs during a 27-month period. The rates of overall WO, WO due to infection, and WO due to sterile dehiscence were 39%, 19%, and 19%, respectively (1% developed a traumatic wound). On univariate analysis, PVD, MRSA colonization, DM, and dialysis dependence were all associated with higher rates of overall WO (P < .05). On multivariate analysis, MRSA colonization was associated with higher rates of overall WO (P = .03) and WO due to wound infection (11% vs 45%; P < .01). DM and PVD were associated with higher rates of overall WO and WO due to sterile dehiscence on both univariate and multivariate analysis (P < .05).. Nasal MRSA colonization is associated with higher rates of overall WO and WO due to wound infection. DM and PVD are associated with higher rates of overall WO and WO due to sterile dehiscence but are not associated with WO due to wound infection. Further studies addressing the effect of nasal MRSA eradication on postoperative wound outcomes after MLEA are warranted.

Topics: Aged; Amputation, Surgical; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Retrospective Studies; Risk Factors; Staphylococcal Infections; Surgical Wound Dehiscence; Surgical Wound Infection

Results of a study to determine the utility of methicillin-resistant Staphylococcus aureus (MRSA) active surveillance via nasal-swab screening in predicting the results of clinical respiratory cultures are reported.. A retrospective chart review-based descriptive analysis was conducted at a Veterans Affairs (VA) medical center. VA databases were used to identify adult patients admitted to the facility over a one-year period who underwent both respiratory culture testing and active MRSA surveillance nasal-swab screening during the hospitalization; only data on patients who had a MRSA surveillance swab within 48 hours before or after respiratory culture testing were included in the analysis. The sensitivity, specificity, and positive and negative predictive values of the MRSA screening method were calculated.. Data on a total of 297 respiratory cultures and corresponding nasal-swab results were reviewed. The positive predictive value of the nasal-swab method of MRSA surveillance screening was calculated as 37.5% (95% confidence interval [CI], 21.1-56.3%); the negative predictive value was 99.3% (95% CI, 97.3-99.9%). MRSA screening by nasal swab had a calculated specificity of 92.9% (95% CI, 89.3-95.6%) and sensitivity of 87.5% (95% CI, 57.2-98.2%). Using Fisher's exact test, it was determined that there was a significant association between swab and culture results (p < 0.001).. This analysis demonstrated a notable association between negative results of nasal-swab screening for MRSA and an absence of MRSA growth on respiratory clinical cultures at the study site, suggesting that airway swab screening can be a useful tool for streamlining antimicrobial therapy.

Topics: Aged; Hospitals, Veterans; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Predictive Value of Tests; Respiratory Tract Infections; Retrospective Studies; Sensitivity and Specificity; Staphylococcal Infections

This prospective cohort study describes carriage of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in household members from 49 farrowing pig farms in the Netherlands (2010-2011). Of 171 household members, 4% were persistent MRSA nasal carriers, and the MRSA prevalence on any given sampling moment was 10% (range 7-11%). Working in the stables (of which 98% was MRSA-positive, prevalence ratio (PR) = 2.11 per 10 hours), working with sows (PR=1.97), and living with an MRSA-positive pig farmer (PR=4.63) were significant determinants for MRSA carriage. Significant protective factors were carriage of methicillin-susceptible Staphylococcus aureus (MSSA) (PR=0.50), and wearing a facemask when working in the stables (37% decreased prevalence). All MRSA strains during the study period were known livestock-associated types. The bacteriophage φ3 was not found in household members. Transmission from pigs and the environment appeared to be important determinants; human-to-human transmission could not sufficiently be differentiated. Wearing a facemask when working in the stables and carriage of MSSA are potential interventional targets.

Topics: Animals; Carrier State; Farmers; Humans; Livestock; Methicillin-Resistant Staphylococcus aureus; Netherlands; Nose; Oropharynx; Prospective Studies; Staphylococcal Infections; Swine

To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization in hemodialysis patients and to analyze the cost-effectiveness of our screening approach compared with an alternative strategy. DESIGN Screening study and cost-effectiveness analysis.. Analysis of twice-yearly MRSA prevalence studies conducted in the hemodialysis unit of a 950-bed tertiary care hospital from January 1, 2004, through December 31, 2013. For this purpose, nasal swab samples were cultured on MRSA screening agar (mannitol-oxacillin biplate).. There were 20 mass screenings during the 10-year study period. We identified 415 patients participating in at least 1 screening, with an average of 4.5 screenings per patient. Of 415 screened patients, 15 (3.6%) were found to be MRSA carriers. The first mass screening in 2004 yielded the highest percentage of MRSA (6/101 [6%]). Only 7 subsequent screenings revealed new MRSA carriers, whereas 4 screenings confirmed previously known carriers, and 8 remained negative. None of the carriers developed MRSA bacteremia during the study period. The total cost of our screening approach, that is, screening and isolation costs, was US $93,930. The total cost of an alternative strategy (ie, no mass screening administered) would be equivalent to costs of isolation of index cases and contact tracing was estimated to be US $5,382 (difference, US $88,548).. In an area of low MRSA endemicity (<5%), regular nasal screenings of a high-risk population yielded a low rate of MRSA carriers. Twice-yearly MRSA screening of dialysis patients is unlikely to be cost-effective if MRSA prevalence is low.

Topics: Aged; Carrier State; Cost-Benefit Analysis; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Renal Dialysis; Staphylococcal Infections

The BD Max MRSAXT and the BD Max StaphSR assays were validated for the detection of methicillin-resistant Staphylococcus aureus (MRSA) in ESwab samples. In addition, the BD Max StaphSR assay was evaluated for its ability to detect and differentiate S. aureus and MRSA in the same sample. A total of 255 ESwab samples collected from the anterior nares of patients were tested by each of three BD Max assays, including the BD Max MRSA first-generation assay. The results were compared to those of direct and enrichment culture. Additionally, a challenge panel comprising 14 control strains was evaluated to determine the ability of these assays to correctly identify MRSA and also appropriately differentiate S. aureus by the BD Max StaphSR assay. Out of 255 clinical samples tested, 161 were negative and 30 were positive for MRSA, and 45 were positive for S. aureus (by BD Max StaphSR) and negative for MRSA by all three PCR assays and culture. Nineteen samples had discrepant results; all of them were retested by additional laboratory testing. All strains from the challenge panel were correctly identified or excluded by the BD Max MRSAXT and BD Max StaphSR assays. The results showed that the BD Max StaphSR and the BD MRSAXT assays have excellent sensitivity (94.3%) and specificity (97.7%) for detecting MRSA. The BD Max StaphSR assay demonstrated excellent sensitivity (96.4%) and specificity (93.6%) for detecting S. aureus.

Topics: Bacteriological Techniques; Carrier State; Humans; Methicillin Resistance; Molecular Diagnostic Techniques; Nose; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

The aim of this prospective study was to establish the methicillin-resistant Staphylococcus aureus (MRSA) colonization rates in pediatric outpatients with type 1 diabetes mellitus, while also evaluating changes in colonization rates over time. There was no significant difference between 2005 and 2013 patients in terms of demographic and clinical findings. MRSA colonization rates were 0.7% (in 101 patients) and 0.9% (in 134 patients) (P = .84). Although increased MRSA colonization has become a significant problem worldwide, it does not seem to be a major issue in our diabetic outpatient population.

Topics: Adolescent; Carrier State; Child; Diabetes Mellitus, Type 1; Female; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Outpatients; Prevalence; Prospective Studies; Staphylococcal Infections

In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureus strains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureus were collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus (MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus (MSSA) was recovered from 24. Most-46 of the 63-wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL(+)) group of S. aureus clone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureus infections, 30 were also colonized by S. aureus in the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing.

Topics: Carrier State; Community Health Centers; Community-Acquired Infections; Genetic Variation; Genotype; Humans; Methicillin Resistance; Molecular Epidemiology; Molecular Typing; New York City; Nose; Soft Tissue Infections; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Wounds and Injuries

Staphylococcus aureus is one of the major agents of both healthcare- and community-associated infections. Nasal carriage of S. aureus has been reported in approximately 37% of healthy persons.. 1. To investigate the prevalence of nasal carriage of S. aureus and MRSA in healthy persons of the age group 18-26 years (general medicine students of the Palacký University Olomouc). This type of information is not available in the Czech Republic. 2. To find whether the prevalence of nasal carriage strains of S. aureus and MRSA varies over the years of studies. 3. To compare the Year 1 (baseline) and Year 5 (after a long, close contact with the indoor environment of health-care facilities) general medicine students for nasal carriage of S. aureus and MRSA strains.. The prevalence study was conducted for over 12 months in 2012 and 2013. Nasal swabs were taken from the general medicine students participating in the study. Each subject was sampled once.. In total, 307 samples were collected: 206 samples from the Year 1 students and 101 from the Year 5 students. Sixty-one (about 32%) Year 1 students and 32 (30%) Year 5 students were positive for S. aureus. Of them, 94 (30.6%) were males and 213 (69.4%) were females.. The observed prevalence of nasal S. aureus carriage is consistent with the literature data. No statistically significant difference in the prevalence of nasal carriage of S. aureus was found between the Year 1 and Year 5 general medicine students.

Topics: Adolescent; Adult; Carrier State; Cross-Sectional Studies; Czech Republic; Female; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Students, Medical; Universities; Young Adult

To identify Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage status among medical students during their clinical rotations.. This cross-sectional study detected the prevalence of MRSA among medical students at King Abdulaziz University (KAU), Jeddah, Saudi Arabia, using molecular approaches. Nasal swabs were collected from 150 internship and sixth-year medical students between September 2014 and January 2015, and compared with the control group of 32 third-year medical students who were not exposed to clinical work. Polymerase chain reaction (PCR) screening was performed to identify Staphylococcus aureus (S. aureus) nucgene, and an additional PCR was performed on S. aureus positive samples to detect the presence of mecA gene.. Out of 150 students screened, 38 were nasal carriers of S. aureus. The prevalence of methicillin-sensitive S. aureus (MSSA) carriers was 18.7% (n=28), whereas 10 students (6.7%) were mecA-positive, representing MRSA carriers. Interns carry MRSA more than 6th year students and students who were not exposed to clinical work (p less than 0.05), while MSSA is found more in students who were not exposed to clinical work (p less than 0.01).. We found MRSA carriers among medical students at KAU, which showed a possible contribution of this group to transmit infection to hospitalized patients. Medical students must receive sufficient knowledge regarding control measures to avoid spread of this infection in hospitals.

Topics: Carrier State; Case-Control Studies; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Saudi Arabia; Staphylococcal Infections; Students, Medical

A major risk factor for the development of surgical site infections is Staphylococcus aureus carriage. Compared with non-carriers, S. aureus carriers have up to a 14-fold greater risk for post-surgical infections. Pre-operative screening for S. aureus carriage is controversial. Yet, targeted screening in high-risk patients or from clinically relevant sites may be beneficial. We aimed to determine whether S. aureus detection in high-risk surgical patients would be increased by culturing surgical sites, in addition to the nares, vs. nares-only culturing.. Adults undergoing pre-operative evaluations in orthopedic and neurosurgical clinics were eligible for participation. For each subject, specimens were collected from the anterior nares and from the proposed surgical site. Samples were inoculated onto methicillin-resistant S. aureus-selective chromogenic agar plates and blood agar plates.. Of 150 subjects, 80 (53.3%) were women and 70 (46.7%) men. The mean age was 61 years and 77/150 (51.3%) had a BMI≥30. Culture results were available for 147/150 subjects. Of the 147 surgical site cultures, 54 (36.7%), 51 (34.7%), and 28 (19.0%) were collected from knee, hip, and lumbar sites, respectively; the remaining 14 (9.5%) were from cervical, thoracic, or infra-clavicular sites. Overall, 35/147 (23.8%) nasal cultures grew S. aureus; 29/147 (19.7%) grew methicillin-susceptible S. aureus (MSSA), and 6/147 (4.1%) grew methicillin-resistant S. aureus (MRSA). Only 2/147 (1.4%) surgical site cultures grew S. aureus; both grew MSSA and MSSA was cultured also from the nasal swabs of these subjects. Using nasal culture+surgical site culture as "true positive," the percentage of additional S. aureus carriers detected by the addition of surgical site screening was zero as compared to nasal screening alone.. The detection of S. aureus carriage in high-risk surgical patients is not improved by swabbing surgical sites in addition to the nares.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Female; Humans; Male; Mass Screening; Middle Aged; Nose; Preoperative Care; Prospective Studies; Risk Assessment; Skin; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) is a common and important cause of colonization and infection in medical intensive care units (ICU). The aim of this study was to assess association factors between MRSA nasal colonization and subsequent infections in medical ICU patients by clinical investigation and molecular genotyping. A prospective cohort observational analysis of consecutive patients admitted to medical ICUs between November 2008 and May 2010 at a tertiary teaching hospital were included. To detect MRSA colonization, the specimens from the nares were obtained within 3 days of admission to the ICU and again 1 week following admission to the ICU. Genetic relatedness for colonized and clinical isolates from each study patient with MRSA infection were analyzed and compared. A total of 1266 patients were enrolled after excluding 195 patients with already present MRSA infections. Subsequent MRSA infection rates were higher in patients with nasal colonization than in those without (39.1% versus 14.7%, respectively). Multivariate Poisson regression analysis demonstrated that nasal MRSA colonization (relative risk [RR]: 2.50; 95% confidence interval [CI]: 1.90-3.27; P < 0.001) was independent predictors for subsequent MRSA infections. History of tracheostomy, however, was a protective predictor in all patients (RR: 0.38; 95% CI: 0.18-0.79; P = 0.010) and in patients with MRSA nasal colonization (RR: 0.22; 95% CI: 0.55-0.91; P = 0.037). Molecular genetics studies revealed that most MRSA isolates were healthcare-associated clones and that nasal and clinical isolates exhibited up to 75% shared identity. Methicillin-resistant S. aureus nasal colonization was significantly associated with subsequent MRSA infection among medical ICU patients. Previous MRSA infection was associated with subsequent MRSA infections, and history of tracheostomy associated with reducing this risk. Most MRSA isolates were healthcare-associated strains that were significantly correlated between nasal and clinical isolates.

Topics: Aged; Aged, 80 and over; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multilocus Sequence Typing; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Taiwan

There is a global trend for an increase in prevalence of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation in children. A decade ago, MRSA colonisation was studied in Swiss paediatric hospitals and revealed an extraordinarily low proportion (<1 %). The primary goal of this study was to determine if the current proportion of nasal colonisation with MRSA in hospitalised children was still favourable. We aimed to screen all children from the age of 0-16 years admitted to the paediatric and surgical wards at the University Children's Hospital Basel (UKBB) during 8 pre-defined surveillance weeks. After obtaining consent, a nasal swab was taken and analysed for growth of S. aureus. Furthermore, a standardised questionnaire was completed by interview with a parent. Of 535 eligible children, 340 (64 %) were enrolled. Mean age was 6.2 years (median 4.3, IQR 1 to 11.25), 111 (33 %) children were colonised with S. aureus but no MRSA was found.. The prevalence of MRSA in children admitted to the UKBB during this surveillance period was zero. General MRSA screening in hospitalised children continues to be unjustified in our area.. • The prevalence of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation in children is increasing in many regions worldwide. • Surveillance for MRSA colonisation in healthcare settings varies considerably.. • Periodic and risk-factor-based surveillance for MRSA colonisation is sufficient when regional prevalence is low.

Topics: Adolescent; Child; Child, Hospitalized; Child, Preschool; Cross Infection; Cross-Sectional Studies; Female; Hospitals, University; Humans; Infant; Infant, Newborn; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Prospective Studies; Risk Assessment; Risk Factors; Staphylococcal Infections; Switzerland

Hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) infections are frequently caused by predominant clusters of closely related isolates that cannot be discriminated by conventional diagnostic typing methods. Whole genome sequencing (WGS) and DNA microarray (MA) now allow for better discrimination within a prevalent clonal complex (CC). This single center exploratory study aims to distinguish invasive (blood stream infection) and non-invasive (nasal colonization) MRSA isolates of the same CC5 into phylogenetic- and virulence-associated genotypic subgroups by WGS and MA. A cohort of twelve blood stream and fifteen nasal MRSA isolates of CC5 (spa-types t003 and t504) was selected. Isolates were propagated at the same period of time from unrelated patients treated at the University of Saarland Medical Center, Germany. Rooted phylotyping based on WGS with core-genome single nucleotide polymorphism (SNP) analysis revealed two local clusters of closely related CC5 subgroups (t504 and Clade1 t003) which were separated from other local t003 isolates and from unrelated CC5 MRSA reference isolates of German origin. Phylogenetic subtyping was not associated with invasiveness when comparing blood stream and nasal isolates. Clustering based on MA profiles was not concordant with WGS phylotyping, but MA profiles may identify subgroups of isolates with nasal and blood stream origin. Among the new putative virulence associated genes identified by WGS, the strongest association with blood stream infections was shown for ebhB mutants. Analysis of the core-genome together with the accessory genome enables subtyping of closely related MRSA isolates according to phylogeny and presumably also to the potential virulence capacity of isolates.

Topics: Amino Acid Substitution; Bacteremia; Cluster Analysis; Genome, Bacterial; Genomics; High-Throughput Nucleotide Sequencing; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Oligonucleotide Array Sequence Analysis; Phylogeny; Polymorphism, Single Nucleotide; Staphylococcal Infections; Virulence

Bacteria respond to ever-changing environments through several adaptive strategies. This includes mechanisms leading to a high degree of phenotypic variability within a genetically homogeneous population. In Staphylococcus aureus, the capsular polysaccharide (CP) protects against phagocytosis, but also impedes adherence to endothelial cells and/or matrix proteins. We analysed the regulation of core biosynthesis genes (capA-P) necessary for CP synthesis using single-cell assays (immunofluorescence and promoter-activity). In persistent human carriers, we found a distinct subpopulation of nasal S. aureus to be CP positive. In vitro, cap expression is also heterogeneous and strongly growth-phase dependent. We asked whether this peculiar expression pattern (earlyOff/lateHeterogen) is orchestrated by the quorum system Agr. We show that the Agr-driven effector molecule RNAIII promotes cap expression largely via inactivation of the repressor Rot. High NaCl, deletion of CodY or Sae also resulted in higher cap expression but did not change the earlyOFF/lateHeterogen expression pattern. Activity of the quorum system itself is largely homogenous and does not account for the observed heterogeneity of cap expression or the strictly growth phase dependent expression. Our findings are in contrast to the prevailing view that quorum sensing is the main driving force for virulence gene expression when bacterial cell densities increase.

Topics: Bacterial Capsules; Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Nose; Phenotype; Polysaccharides, Bacterial; Promoter Regions, Genetic; Quorum Sensing; Repressor Proteins; RNA, Bacterial; Staphylococcal Infections; Staphylococcus aureus; Virulence

The objective of this study was to define the nasal microbiome of hospital inpatients who are persistently colonized with methicillin-resistant Staphylococcus aureus (MRSA) compared with matched, non-colonized controls.. Twenty-six persistently MRSA-colonized subjects and 26 matched non-colonized controls were selected from the screening records of the infection control program at the Department of the Veteran Affairs Eastern Colorado Health Care System (VA-ECHCS). The nasal microbiotas were analyzed with PCR amplification and sequencing of the 16S ribosomal RNA (rRNA) gene. Comparison of all variables across the groups was performed using stratified logistic regression to account for the one-to-one matching. Canonical discriminant analysis was performed to assess differences in bacterial community across the two groups. Competing organisms were cocultured with MRSA in vitro.. There was a negative association between MRSA colonization and colonization with Streptococcus spp. At the species level, multivariate analysis demonstrated a statistically significant negative association between colonization with Streptococcus mitis or Lactobacillus gasseri and MRSA. Coculture experiments revealed in vitro competition between S. mitis and all of the 22 MRSA strains isolated from subjects. Competition was blocked by addition of catalase to the media. Persistently colonized subjects had lesser microbial diversity than the non-colonized controls.. In a high-risk inpatient setting, bacterial competition in the nasal niche protects some patients from MRSA colonization.

Topics: Adult; Antibiosis; Carrier State; Catalase; Female; Hospitalization; Humans; Lactobacillus; Male; Methicillin-Resistant Staphylococcus aureus; Microbiota; Nose; Polymerase Chain Reaction; Risk Factors; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Streptococcus mitis

We assessed methicillin-resistant Staphylococcus aureus (MRSA) carriage rate among dental students from an Italian university. A total of 157 subjects participated (67 preclinical students and 90 clinical students); samples were collected from the nose, mouth, and skin. Five preclinical students and 0 clinical students were MRSA-positive. Carriage rates were 3.2% (95% confidence interval [CI], 0.4%-6.0%) overall, 7.5% (95% CI, 1.2%-13.8%) in preclinical students and 0% in clinical students. There were 2 MRSA clusters among the preclinical students: 3 second-year and 2 first-year students, who sat close to one another in the classroom the day of the sample. MRSA carriage was not associated with dental health care. The pooled carriage rate among dental students was assessed to obtain a reliable figure of carriage rate unaffected by local conditions. The 4 published surveys were pooled, and the fixed-effects method was used. Among the 484 dental students, the pooled carriage rate was 4.1% (95% CI, 2.4%-5.8%).

Topics: Adult; Carrier State; Cross-Sectional Studies; Female; Humans; Italy; Male; Methicillin-Resistant Staphylococcus aureus; Mouth; Nose; Prevalence; Skin; Staphylococcal Infections; Students, Dental; Universities; Young Adult

An interesting biological phenomenon that is a factor for the spread of antibiotic-resistant strains, such as MRSA, is human nasal carriage. Here, we evaluate several biological hypotheses for this problem in an effort to better understand and narrow the scope of the dominant factors that allow these bacteria to persist in otherwise healthy individuals. First, we set up and analyze a simple PDE model created to generally mimic the interactions of the microbes and nasal immune response. This includes looking at different types of diffusion and chemotaxis terms as well as different boundary conditions. Then, using sensitivity analysis, we walk through several biological hypotheses and compare to the model's results looking for persistent infection scenarios indicated by the model's bacteria component surviving over time.

Topics: Carrier State; Computer Simulation; Humans; Immune Evasion; Mathematical Concepts; Methicillin-Resistant Staphylococcus aureus; Models, Biological; Nose; Staphylococcal Infections

Staphylococcus aureus is the number one cause of hospital-acquired infections. Understanding host pathogen interactions is paramount to the development of more effective treatment and prevention strategies. Therefore, whole exome sequence and chip-based genotype data were used to conduct rare variant and genome-wide association analyses in a Mexican-American cohort from Starr County, Texas to identify genes and variants associated with S. aureus nasal carriage. Unlike most studies of S. aureus that are based on hospitalized populations, this study used a representative community sample. Two nasal swabs were collected from participants (n = 858) 11-17 days apart between October 2009 and December 2013, screened for the presence of S. aureus, and then classified as either persistent, intermittent, or non-carriers. The chip-based and exome sequence-based single variant association analyses identified 1 genome-wide significant region (KAT2B) for intermittent and 11 regions suggestively associated with persistent or intermittent S. aureus carriage. We also report top findings from gene-based burden analyses of rare functional variation. Notably, we observed marked differences between signals associated with persistent and intermittent carriage. In single variant analyses of persistent carriage, 7 of 9 genes in suggestively associated regions and all 5 top gene-based findings are associated with cell growth or tight junction integrity or are structural constituents of the cytoskeleton, suggesting that variation in genes associated with persistent carriage impact cellular integrity and morphology.

Topics: Adult; Aged; Carrier State; Cohort Studies; Exome; Exons; Female; Genetic Variation; Genome-Wide Association Study; Genotype; Humans; Inflammation; Male; Mexican Americans; Middle Aged; Nose; p300-CBP Transcription Factors; Phenotype; Polymorphism, Single Nucleotide; Regression Analysis; Staphylococcal Infections; Staphylococcus aureus; Texas

Staphylococcus aureus nasal colonization is a risk factor for surgical site infection. We conducted a retrospective case-control study of 1,708 consecutively enrolled patients to identify criteria that places orthopaedic surgery patients undergoing spine and total joint arthroplasty surgery at risk for nasal colonization by MRSA and MSSA. Multivariate analysis showed obesity and asthma as significant risk factors for MRSA colonization. The identification of these two risk factors for MRSA colonization may help decolonization programs target patients with these factors for treatment prior to surgery, which could potentially lead to reductions in the rates of surgical site infections.

Topics: Arthroplasty, Replacement; Asthma; Databases, Factual; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Multivariate Analysis; Nose; Obesity; Odds Ratio; Orthopedic Procedures; Retrospective Studies; Risk Factors; Sex Factors; Spine; Staphylococcal Infections; Surgical Wound Infection; Treatment Outcome; White People

Nasal carriage of Staphylococcus aureus is becoming an increasing problem among healthcare workers and community individuals.. To determine the prevalence of methicillin-resistant S. aureus (MRSA) nasal colonization and inducible clindamycin resistance (ICR) of S. aureus among healthcare workers at Soba University Hospital and community members in Khartoum State, Sudan.. Five hundred nasal swabs samples were collected during March 2009 to April 2010. Isolates were identified using conventional laboratory assays and MRSA determined by the disk diffusion method. The D-test was performed for detection of ICR isolates with Clinical Laboratory Standard Institute guidelines.. Of the 114 S. aureus isolated, 20.2% represented MRSA. The occurrence of MRSA was significantly higher among healthcare worker than community individuals [32.7% (18/55) vs. 6.9% (5/59)] (p=0.001). Overall the 114 S. aureus isolates tested for ICR by D-test, 29 (25.4%) yielded inducible resistance. Significantly higher (p=0.026) ICR was detected among MRSA (43.5%) than methicillin-susceptible S. aureus (MSSA) (20.9%).. MRSA nasal carriage among healthcare workers needs infection control practice in hospitals to prevent transmission of MRSA. The occurrence of ICR in S. aureus is of a great concern, D- test should be carried out routinely in our hospitals to avoid therapeutic failure.

Topics: Anti-Bacterial Agents; Carrier State; Clindamycin; Health Personnel; Humans; Infectious Disease Transmission, Professional-to-Patient; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Sudan

Staphylococcus aureus contaminating raw meat may increase nasal colonization risk for occupationally-exposed food handlers. Food handlers from six catering establishments were nasally sampled for S. aureus and completed a questionnaire on carriage risk factors. Isolates were characterized for antibiotic susceptibility, spa type and, for methicillin-resistant strains, SCCmec type. Of 434 food handlers, 99 (22.8%) were colonized with S. aureus. Five isolates were methicillin-resistant belonging to SCCmec IV (2) and V (3). Resistance to tetracycline (20%), and erythromycin (16%) was high, but <10% to other antibiotics. Spa typing revealed 17% of isolates as t189, with 8% each t127 and t1081. Food handlers ever handling raw meat had a significantly higher colonization risk (OR=2.7; 95% CI: 1.7-4.5), increasing to 3.7 (95% CI: 2.0-6.8) for those always exposed. This is the first report of increased colonization risk in food handlers exposed to raw meat. This occupational hazard may increase infection risk, so improved compliance with workplace hygiene may be required.

Topics: Anti-Bacterial Agents; Carrier State; Drug Resistance; Female; Food Handling; Food Microbiology; Humans; Male; Meat; Methicillin-Resistant Staphylococcus aureus; Nose; Occupational Diseases; Occupational Exposure; Odds Ratio; Risk Factors; Staphylococcal Infections

Topics: Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus, particularly methicillin-resistant (MRSA), is an important pathogen in neonatal intensive care units (NICUs). Carriage of S. aureus is a significant risk factor for subsequent infection.. To determine the current status of MRSA prevalence among NICU-hospitalized infants in Taiwan, we conducted this pilot island-wide survey.. On two designated dates in 2011, each patient who stayed in the NICUs of 7 participating hospitals was included. Nasal and umbilical swabs were obtained and sent for detection of S. aureus. The prevalence and risk factors for MRSA carriage were analyzed. MRSA strains were tested for antimicrobial susceptibility and underwent molecular characterization.. A total of 251 subjects were included. The overall prevalence of S. aureus and MRSA carriage was 13 and 4.4%, respectively. Previous skin and soft tissue infection was the only predictor in multivariate analysis (OR 40.36; 95% CI 2.32-702.64; p = 0.011). Among 11 MRSA isolates, 3 pulsotypes were identified, with one major type (73%). Nine isolates carried a type IV staphylococcal chromosomal cassette, and 2 carried the type VT. All but one MRSA isolate belonged to linage sequence type 59, the community clone in Taiwan.. On a designated date, 4.4% of the infants staying in NICUs in Taiwan carried almost genetically identical community strains of MRSA. MRSA colonization in these infants was significantly associated with previous skin and soft tissue infection.

Topics: Female; Humans; Infant; Infant, Newborn; Intensive Care Units, Neonatal; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Pilot Projects; Prevalence; Staphylococcal Infections; Taiwan; Umbilicus

The prevalence of clonal complex (CC) 398 methicillin-susceptible Staphylococcus aureus (MSSA) was unexpectedly high among bone and joint infections (BJIs) and nasal-colonizing isolates in France, with surprising geographical heterogeneity. With none of the major, most-known staphylococcal virulence genes, MSSA CC398 BJI was associated with lower biological inflammatory syndrome and lower treatment failure rates.

Topics: Adult; Aged; Arthritis, Infectious; Bone Diseases, Infectious; Carrier State; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Retrospective Studies; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.

Topics: Adolescent; Asymptomatic Infections; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Exotoxins; Female; Health Personnel; Hospitals, Pediatric; Humans; Infant; Leukocidins; Libya; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Mothers; Nose; Polymerase Chain Reaction; Staphylococcal Infections

Our purpose was to determine the dynamics of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage and its determinants in persons working at pig farms, in order to identify targets for interventions. This prospective cohort study surveyed 49 pig farms in the Netherlands on six sampling dates in 1 year (2010-11). Nasal and oropharyngeal swabs were collected, as well as environmental surface samples from stables and house. Of 110 pig farmers, 38% were persistent MRSA nasal carriers. The average cross-sectional MRSA prevalence was 63%. Methicillin-susceptible S. aureus (MSSA) nasal carriage was associated with fewer MRSA acquisitions (prevalence rate (PR) = 0.47, p 0.02). In multivariate analysis, an age of 40-49 years (PR = 2.13, p 0.01), a working week of ≥40 h (PR=1.89, p 0.01), giving birth assistance to sows (PR=2.26, p 0.03), removing manure of finisher pigs (PR=0.48, p 0.02), and wearing a facemask (PR = 0.13, p 0.02) were significantly related with persistent MRSA nasal carriage. A higher MRSA exposure in stables was associated with MRSA in pig farmers (p <0.0001). This study describes a very high prevalence of LA-MRSA carriage in pig farmers, reflecting extensive exposure during work. We identified the possible protective effects of MSSA carriage and of continuously wearing a facemask during work.

Topics: Adolescent; Adult; Aged; Animals; Carrier State; Cross-Sectional Studies; Female; Humans; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Mouth; Netherlands; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Sus scrofa; Young Adult

Coagulase-negative staphylococci (CoNS) are believed to function as reservoirs, as well as possible sources of staphylococcal chromosome cassette mec (SCCmec) to Staphylococcus aureus, but the frequency, preferred partners, and factors promoting SCCmec transfer are not known. Such postulated in vivo genetic transfer events are likely to occur at anatomical sites such as the normal nasal mucosa, which is known to be colonized by both CoNS and coagulase positive staphylococci. In this study, we characterized S. aureus and CoNS strains colonizing the anterior nares of 67 patients in Denmark. A total of 54 patients (80%) were colonized with staphylococci that included nine different species identified by internal transcribed spacer PCR (ITS-PCR) and 16S RNA sequencing. The highest rates of colonization were found for S. epidermidis (58%) and S. aureus (39%). Methicillin resistance was present in S. aureus (53%), S. epidermidis (53%), S. haemolyticus (33%), and S. hominis (62%). Genetic backgrounds were characterized by spa typing for S. aureus and by pulsed-field gel electrophoresis for CoNS. SCCmec typing showed that SCCmec type IV (2B) was the most common in the entire collection (65%). Carriage of multiple species was detected in 20 patients (30%), 16 of whom were colonized with both S. aureus and S. epidermidis. In two cases, simultaneous carriage of different methicillin resistant species was detected. However, the strains carried different SCCmec types. Additional studies in the same epidemiological settings are warranted to identify interspecific genetic events that involve the acquisition of SCCmec by S. aureus.

Topics: Adult; Bacterial Typing Techniques; Carrier State; Chromosomes, Bacterial; Denmark; DNA, Intergenic; Gene Transfer, Horizontal; Humans; Infant; Infant, Newborn; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; RNA, Ribosomal, 16S; Staphylococcal Infections; Staphylococcus epidermidis; Staphylococcus haemolyticus; Staphylococcus hominis

Data of Staphylococcus aureus carriage in Indonesian hospitals are scarce. Therefore, the epidemiology of S. aureus among surgery patients in three academic hospitals in Indonesia was studied. In total, 366 of 1,502 (24.4%) patients carried S. aureus. The methicillin-resistant S. aureus (MRSA) carriage rate was 4.3%, whereas 1.5% of the patients carried Panton-Valentine leukocidin (PVL)-positive methicillin-sensitive S. aureus (MSSA). Semarang and Malang city (odds ratio [OR] 9.4 and OR 9.0), being male (OR 2.4), hospitalization for more than 5 days (OR 11.708), and antibiotic therapy during hospitalization (OR 2.6) were independent determinants for MRSA carriage, whereas prior hospitalization (OR 2.5) was the only one risk factor for PVL-positive MSSA carriage. Typing of MRSA strains by Raman spectroscopy showed three large clusters assigned type 21, 24, and 38, all corresponding to ST239-MRSA-SCCmec type III. In conclusion, MRSA and PVL-positive MSSA are present among patients in surgical wards in Indonesian academic hospitals.

Topics: Adolescent; Adult; Asymptomatic Infections; Bacterial Proteins; Bacterial Toxins; DNA, Bacterial; Exotoxins; Female; Hospitalization; Humans; Indonesia; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Penicillin-Binding Proteins; Pharynx; Risk Factors; Spectrum Analysis, Raman; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Axilla; Carrier State; Cross Infection; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Admission; Patient Isolation; Patient Selection; Perineum; Pharynx; Risk Assessment; Staphylococcal Infections; Time Factors

Staphylococcus aureus causes purulent bacterial infections with a considerable number of life-threatening complications and thus, is a serious cost factor in public health. Up to 50% of a given population could asymptomatically carry Staphylococcus aureus in their nares, thereby serving as a source for contact transmissions and endogenous infections. Nasal swab-based screening techniques are widely used to identify suchcarriers. This study investigated the skill of medical professionals in taking nasal swabs and the effect of teaching on improving bacterial recovery rates.. 364 persons with different medical educational background participated in this study. A novel anatomically correct artificial nose model was implemented and inoculated with a numerically defined mixture of Staphylococcus aureus and Staphylococcus epidermidis bacteria. Utilizing regular clinical swabs, participants performed screening of the inoculated nose models before and after standardized theoretical, visual, and practical teaching. Recovery of bacteria was measured by standard viable count techniques. Data were analyzed statistically by nonparametric tests.. It could be demonstrated that combined theoretical and practical teaching improved bacterial recovery rates. Even experienced medical professionals increased their detection levels after training. Recovery rates of bacteria varied significantly between trained (158.1 CFU) and untrained (47.5 CFU) participants (Wilcoxon test, p<0.001; Kolmogorov-Smirnov test, p<0.001).. Swabs are commonly used to detect nasal carriage of Staphylococcus aureus in patients. The present teaching algorithm combined with the novel nose model offers an excellent precondition to improve knowledge and performance of this technique. Increased detection rates may prevent from contact transmission due to suboptimum hygienic patient handling. Consecutively, this effect could reduce costs for patient care. This study highlights the tremendous potential of combined theoretical, visual, and practical teaching methods in this field--and uncovers its actual necessity. Therefore, this training method can be recommended for all medical institutions.

Topics: Bacteriological Techniques; Carrier State; Education, Medical; Female; Health Personnel; Humans; Male; Mass Screening; Models, Anatomic; Nasal Cavity; Nose; Staphylococcal Infections; Staphylococcus aureus; Students, Medical

Rates of community-associated Staphylococcus aureus, and particularly of methicillin-resistant Staphylococcus aureus (MRSA) in children, have increased in recent years. We investigated rates of nasal colonization of S. aureus, and a possible correlation between nasal carriage and wound infection.. A prospective study of children scheduled for elective day-care surgical procedures between January 2008 and December 2012 at one medical center. Nasal swabs were taken before surgery, and follow-up was performed 1-2 weeks following surgery.. Of 1,127 children (median age 2 years, 70.6% males), positive nasal swabs were detected in 228 (20.2%). Rates of S. aureus nasal carriage were lowest for ages 6 months to 2 years and highest for ages 4-11 years. Child's sex did not associate with the risk for positive nasal swabs. Positive nasal swabs for MRSA were detected in five boys (0.62% of the population). Five children (0.44%) had wound infection. None of them was a nasal carrier.. No correlation was observed between positive nasal swabs and wound infection in children who were candidates for elective ambulatory operations. This suggests that evaluation of S. aureus nasal carriage and eradication may not be necessary in this population.

Topics: Adolescent; Age Factors; Ambulatory Surgical Procedures; Carrier State; Child; Child, Preschool; Elective Surgical Procedures; Female; Follow-Up Studies; Humans; Infant; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

This study investigated the prevalence of nasal carriage of staphylococci in dogs and determined the characteristics of the isolates. A total of 724 dogs from 87 veterinary practices across the mainland UK were screened for carriage of Staphylococcus spp. All isolates were examined for meticillin resistance (MR) and the presence of the mecA gene investigated in those isolates showing resistance. All coagulase-positive staphylococci and MR coagulase-negative staphylococci (MRCoNS) were subjected to antimicrobial susceptibility testing. Spa typing and DNA microarray analysis of resistance and virulence genes was carried out on all MR S. aureus (MRSA) and a subset of meticillin susceptible S. aureus (MSSA). Staphylococci were isolated from 399 (55.1%) of the dogs; only seven (1%) carried MRSA, all of which were identified as the dominant UK healthcare-associated strain (EMRSA-15, ST22). MSSA was identified in 47 (6.5%) dogs, the sequence types of which have been suggested as precursors to successful MRSA clones. Forty (5.5%) dogs carried MRCoNS, while no dogs carried MR S. pseudintermedius, although this is increasingly reported in mainland Europe. Resistance to antimicrobials among the isolates varied between species, with multidrug resistance (MDR) in 87.5% of MRCoNS and 21.8% of coagulase positive staphylococci. Microarray analysis of MRSA and a subset of MSSA isolates identified numerous virulence genes associated with pathogenesis, which are commonly identified in isolates of human origin. However, no isolates carried Panton-Valentine leukocidin (PVL) genes. This study suggests that MRSA carriage is low in the vet visiting dog population, but there is a diverse range of virulence and resistance determinants in canine S. aureus and MRCoNS isolates.

Topics: Animals; Anti-Bacterial Agents; Antigens, Bacterial; Bacterial Proteins; Carrier State; Dog Diseases; Dogs; Drug Resistance, Multiple; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Penicillin-Binding Proteins; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus; United Kingdom; Veterinary Medicine; Virulence Factors

Recent increases in the incidence and severity of staphylococcal infections renewed interest in studies that assess the burden of asymptomatic carriage of Staphylococcus aureus in the community setting. We conducted a population-based survey in the city of Botucatu, Brazil (122,000 inhabitants), in order to identify the prevalence of nasal carriage of Staphylococcus aureus (including methicillin-resistant strains). Nasal swabs were obtained from 686 persons over one year of age. Resistance to methicillin was assessed through phenotypic methods, identification of the mecA gene and typing of the Staphylococcal Chromosome Cassette mec (SCCmec). Methicillin-resistant S. aureus (MRSA) isolates were characterized using Pulsed-Field Gel Electrophoresis (PFGE), Multilocus Sequence Typing (MLST) and spa typing. Polymerase chain reaction was applied to identify genes coding for Panton-Valentine Leukocidin (PVL) in isolates. The prevalence of overall S. aureus carriage was 32.7% (95%CI, 29.2%-36.2%). Carriers were significantly younger (mean age, 28.1 versus 36.3 for non-carriers; OR for age, 0.98; 95%CI, 0.97-0.99) and likely to report recent skin infection (OR, 1.85; 95%CI, 1.03-3.34). Carriage of methicillin-resistant S. aureus (MRSA) was found in 0.9% of study subjects (95%CI, 0.4%-1.8%). All MRSA isolates harbored SCCmec type IV, and belonged to spa types t002 or t021, but none among them harbored genes coding for PLV. In MLST, most isolates belonged to clones ST5 or ST1776. However, we found one subject who carried a novel clone, ST2594. Two out of six MRSA carriers had household contacts colonized with isolates similar to theirs. Our study pointed to dissemination of community-associated MRSA among the Brazilian population.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asymptomatic Diseases; Brazil; Child; Child, Preschool; Cities; Data Collection; Female; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Staphylococcal Infections; Staphylococcus aureus; Young Adult

The epidemiology of Staphylococcus aureus in the community in Ghana was never investigated prior to this study. The aims of the study were: i) to assess prevalence of nasal S. aureus carriage in Ghanaian people living in an urban and a rural area, and ii) to identify phenotypic and genotypic traits of strains isolated from the two communities. Nasal swabs were collected from healthy individuals living in an urban community situated in the suburb of the capital city, Accra (n = 353) and in a rural community situated in the Dangme-West district (n = 234). The overall prevalence of nasal carriage was 21% with a significantly higher prevalence in the urban (28%) than in the rural community (11%) (p<0.0001). The levels of antimicrobial resistance were generally low (<5%) except for penicillin (91%) and tetracycline (25%). The only two (0.3%) MRSA carriers were individuals living in the urban area and had been exposed to hospitals within the last 12 months prior to sampling. Resistance to tetracycline (p = 0.0009) and presence of Panton-Valentine leukocidin (PVL) gene (p = 0.02) were significantly higher among isolates from the rural community compared to isolates from the urban community. Eleven MLST clonal complexes (CC) were detected based on spa typing of the 124 S. aureus isolates from the two communities: CC8 (n = 36), CC152 (n = 21), CC45 (n = 21), CC15 (n = 18), CC121 (n = 6), CC97 (n = 6), CC30 (n = 5), CC5 (n = 5), CC508 (n = 4), CC9 (n = 1), and CC707 (n = 1). CC8 and CC45 were less frequent in the rural area than in the urban area (p = 0.02). These results reveal remarkable differences regarding carriage prevalence, tetracycline resistance, PVL content and clonal distribution of S. aureus in the two study populations. Future research may be required to establish whether such differences in nasal S. aureus carriage are linked to socio-economic differences between urban and rural communities in this African country.

Topics: Adult; Anti-Bacterial Agents; Cross Infection; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Female; Ghana; Humans; Male; Middle Aged; Multilocus Sequence Typing; Nose; Penicillins; Rural Population; Staphylococcal Infections; Staphylococcus aureus; Tetracycline; Urban Population

Infections by Staphylococcus spp. are often associated with wounds, especially in hospitalized patients. Wounds may be the source of bacteria causing cross-contamination, and are a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) infection. The aim of this study was to investigate the prevalence of wound colonization by Staphylococcus spp., especially S. aureus and MRSA, in hospitalized patients, and to identify the factors associated with such colonization.. This cross-sectional study enrolled patients with wounds who were hospitalized in a remote and underdeveloped inland region of northeastern Brazil with extreme poverty. Samples were collected using sterile swabs with 0.85% saline solution, and coagulase-negative Staphylococcus spp., S. aureus, and MRSA were identified using standard laboratory procedures. Data regarding the sociodemographic characteristics, antibiotic use, and comorbidities of the patients were collected using the medical records and a questionnaire.. A total of 125 wounds were analyzed. The patients had a mean age of 63.88 years and a mean 3.84 years of school education. Eighty-one wounds (64.80%) were colonized by Staphylococcus spp. Twenty-five wounds (20%) were colonized by S. aureus, 32% of which were colonized by MRSA. Wound colonization by Staphylococcus spp. was associated with pneumonia or other respiratory disease (p = 0.03). Wound colonization by S. aureus was associated with nasal colonization by S. aureus (p < 0.001), fewer days of prior antibiotic use (p = 0.04), admission to a medical ward (p = 0.02), and age >65 years (p = 0.05). Among patients with wound colonization by MRSA, 37.50% had a history of prior antibiotic use, 75% had two or more comorbidities, 25% had cancer or diabetes, 50% had cardiovascular disease, and 50% died.. Wounds can be the source of Staphylococcus spp. infection, and high proportions of wounds are colonized by S. aureus and MRSA. Nasal colonization by S. aureus may be a source for wound colonization by S. aureus, illustrating the importance of preventing cross-contamination in hospital environments, especially among elderly patients. Wounds should be carefully managed to prevent microbial spread, thereby assisting patient recovery and reducing healthcare costs.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Brazil; Cross-Sectional Studies; Female; Hospitalization; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus

Staphylococcus aureus is a bacterium causing infections in both community and hospitals. S. aureus nasal colonization increases the risk of acquiring S. aureus infection. In this study, the prevalence of S. aureus nasal colonization was determined in Thai children, showing that nasal colonization was found in 78 of 217 subjects and the methicillin-resistant S. aureus (MRSA) carriage rate was present in 5 of 217 children. Among 78 S. aureus isolates, resistance to penicillin, erythromycin, clindamycin, chloramphenicol, trimethoprim/sulfamethoxazole, oxacillin and cefoxitin was found in 99%, 8%, 1%, 4%, 1%, 8% and 6% of the isolates, respectively. The presence of 3 adhesin genes, investigated by PCR, revealed that among 78 isolates, fnbA, icaAD and cna was detected in 73, 72 and 48 isolates, respectively but not in the 5 MRSA isolates. Ninety-five percent and 31% of S. aureus isolates were able to form strong and weak biofilms, respectively. Four MRSA isolates that lacked icaAD were non-biofilm-forming strains. These results revealed a high prevalence of S. aureus nasal colonization in healthy Thai children with 2% being MRSA. Effective strategies to prevent S. aureus transmission and infection are therefore needed in the Thai community.

Topics: Adhesins, Bacterial; Anti-Bacterial Agents; Apoptosis Regulatory Proteins; Biofilms; Carrier State; Child; Drug Resistance, Bacterial; Female; Genes, Bacterial; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Thailand

Clinical significance of Staphylococcus aureus colonization has been demonstrated in hospital settings; however, studies in the community have shown contrasting results regarding the relevance of colonization in infection by community-associated MRSA (CA-MRSA). In Colombia there are few studies on S. aureus colonization. The aim of this study was to determine the molecular and epidemiological characteristics of nasal colonization by S. aureus (MSSA-MRSA) in children from a university hospital and day care centers (DCCs) of Medellin, Colombia.. An observational cross-sectional study was conducted in 400 children (200 in each setting), aged 0 months to 5 years, during 2011. Samples were collected from each nostril and epidemiological information was obtained from the parents. Genotypic analysis included spa typing, PFGE, MLST, SCCmec typing, detection of genes for virulence factors and agr groups.. Frequency of S. aureus colonization was 39.8% (n = 159) (hospital 44.5% and DCCs 35.0%) and by MRSA, 5.3% (n = 21) (hospital 7.0% and DCCs 3.5%). Most S. aureus colonized children were older than two years (p = 0.005), the majority of them boys (59.1%), shared a bedroom with a large number of people (p = 0.028), with history of β-Lactamase inhibitors usage (p = 0.020). MSSA strains presented the greatest genotypic diversity with 15 clonal complexes (CC). MRSA isolates presented 6 CC, most of them (47.6%) belonged to CC8-SCCmec IVc and were genetically related to previously reported infectious MRSA strains.. Differences in epidemiological and molecular characteristics between populations may be useful for the understanding of S. aureus nasal colonization dynamics and for the design of strategies to prevent S. aureus infection and dissemination. The finding of colonizing MRSA with similar molecular characteristics of those causing infection demonstrates the dissemination capacity of S. aureus and the risk of infection among the child population.

Topics: Bacterial Proteins; beta-Lactamase Inhibitors; Child Day Care Centers; Child, Preschool; Cross-Sectional Studies; Female; Genotype; Hospitals, University; Humans; Infant; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Trans-Activators; Virulence Factors

Prior studies published in the cardiothoracic, orthopedic and gastrointestinal surgery have identified the importance of nasal (methicillin-resistant Staphylococcus aureus) MRSA screening and subsequent decolonization to reduce MRSA surgical site infection (SSI). This is the first study to date correlating nasal MRSA colonization with postoperative spinal MRSA SSI.. To assess the significance of nasal MRSA colonization in the setting of MRSA SSI.. A retrospective electronic chart review of patients from year 2011 to June 2013 was conducted for patients with both nasal MRSA colonization within 30 days prior to spinal surgery. Patients who tested positive for MRSA were put on contact isolation protocol. None of these patients received topical antibiotics for decolonization of nasal MRSA.. A total of 519 patients were identified; 384 negative (74%), 110 MSSA-positive (21.2%), and 25 (4.8%) MRSA-positive. Culture positive surgical site infection (SSI) was identified in 27 (5.2%) cases and was higher in MRSA-positive group than in MRSA-negative and MSSA-positive groups (12% vs. 5.73% vs. 1.82%; p=0.01). The MRSA SSI rate was 0.96% (n=5). MRSA SSI developed in 8% of the MRSA-positive group as compared to only in 0.61% of MRSA-negative group, with a calculated odds ratio of 14.23 (p=0.02). In the presence of SSI, nasal MRSA colonization was associated with MRSA-positive wound culture (66.67 vs. 12.5%; p<0.0001).. Preoperative nasal MRSA colonization is associated with postoperative spinal MRSA SSI. Preoperative screening and subsequent decolonization using topical antibiotics may help in decreasing the incidence of MRSA SSI after spine surgery. Nasal MRSA+ patients undergoing spinal surgery should be informed regarding their increased risk of developing surgical site infection.

Topics: Anti-Bacterial Agents; Digestive System Surgical Procedures; Female; Humans; Incidence; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Preoperative Care; Retrospective Studies; Spinal Diseases; Staphylococcal Infections; Surgical Wound Infection

Methicillin-resistant Staphylococcus aureus screening performed for infection control purposes may be useful in guiding decisions regarding the use of broad-spectrum antibiotics in the intensive care unit. A cohort study of adults with ventilator-associated pneumonia (VAP) found that admission MRSA nasal swabs had a negative predictive value of 94% for later MRSA VAP.

Topics: Anti-Bacterial Agents; Cohort Studies; Female; Humans; Infection Control; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pneumonia, Ventilator-Associated; Staphylococcal Infections

Methicillin-resistant Staphylococcus aureus sequence type (ST)398 is widely spread among livestock. People in contact with livestock have a higher risk of testing positive for MRSA. Several experimental settings have been described to study in vivo colonization of MRSA in pigs, each having its own limitations. The aim of this study was to develop a nose-colonization model in pigs to quantitatively study the colonization of MRSA and the co-colonization of MSSA and MRSA. Two experiments were performed: in the first experiment piglets received an intranasal inoculation with MRSA ST398, spa-type t011, and in the second experiment piglets received an intranasal inoculation with two MSSA strains (ST398, spa-type t011 and t034) and two MRSA strains (also ST398, spa-type t011 and t034) to investigate co-colonization. Colonization was quantitatively monitored for 2 weeks in both experiments. Nasal colonization was successfully established in all piglets with stable numbers of S. aureus between 10(4) and 10(6) CFU. MSSA and MRSA were able to co-colonize.

Topics: Animals; Methicillin; Methicillin-Resistant Staphylococcus aureus; Models, Animal; Nose; Staphylococcal Infections; Staphylococcus aureus; Swine; Swine Diseases

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in livestock has refocused attention on S. aureus colonization and transmission in pigs. This study investigated the effect of the S. aureus colonization status of a sow on the colonization status of her piglets, and whether pigs carry the same strain of S. aureus throughout production. Nasal swabs were collected from the piglets of six healthy sows two days after birth and two days before and two days after they were moved into each production stage. The average prevalence of S. aureus colonization varied between 26% and 73%. The odds of being S. aureus positive were almost 12 times higher for piglets born to nasal-positive sows than for those born to nasal-negative sows, and three times higher again for piglets born to sows that were both nasal- and vaginal-positive. Isolates recovered from piglets immediately after birth were indistinguishable from those of the dam as determined by phenotypic and molecular typing, including microarray analysis and optical mapping. All isolates belonged to clonal complex 9 and the majority exhibited a novel spa type, t10449. The findings show that the S. aureus colonization status of the sow influences the colonization status of her piglets in the early production stages but strains carried by pigs change over time. Multiresistant S. aureus was detected, in particular post-weaning. Results suggest that sow status and management practices, including mixing of pigs and antimicrobial usage at weaning, should be considered when implementing control measures for S. aureus on a farm.

Topics: Animals; Female; Ireland; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Typing; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Swine; Swine Diseases; Vagina; Weaning

As healthy children are the main reservoir of respiratory pathogens and the main cause of bacterial diffusion in the community, it could be interesting to investigate the type of screening that should be used during the early years of life in order to obtain a more precise estimate of Staphylococcus aureus circulation. The aim of this study was to evaluate oropharyngeal and nasal S. aureus carriage in otherwise healthy children and adolescents aged 6-17 years.. The oropharyngeal and nasal samples were collected in December 2013 from 497 healthy students attending five randomly selected schools in Milan, Italy, using an ESwab kit, and S. aureus was identified using the RIDA®GENE methicillin-resistant S. aureus (MRSA) system.. Two hundred and sixty-four subjects (53.1%) were identified as S. aureus carriers: 129 (25.9%) oropharyngeal carriers and 195 (39.2%) nasal carriers, of whom 60 (12.1%) were both oropharyngeal and nasal carriers. Oropharyngeal carriage increased with age (p < 0.001), whereas nasal carriage decreased. There was little or no agreement between oropharyngeal and nasal carriage in any of the age groups. MRSA was identified in only three cases (0.6%), always in nasal samples. There were no differences between the carriers and non-carriers in terms of the distribution of age, gender, ethnicity, the number of siblings in the household, exposure to passive smoking, previous clinical history, allergic sensitisation, or previous influenza, pneumococcal and meningococcal vaccinations. The frequency of male children was higher among the subjects with positive nasal and oropharyngeal swabs (66.7%) than among those with positive oropharyngeal swabs alone (46.4%; p = 0.02).. The oropharyngeal carriage of mainly methicillin-sensitive S. aureus is frequent in otherwise healthy children, including a relatively high proportion of those without nasal colonisation. These findings highlight the importance of adding throat to nasal screening when monitoring the circulation of S. aureus in the community.

Topics: Adolescent; Asymptomatic Infections; Carrier State; Child; Family Characteristics; Female; Humans; Italy; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Oropharynx; Respiratory Tract Infections; Schools; Staphylococcal Infections; Staphylococcus aureus

Patients and healthcare workers in a Japanese haemodialysis clinic were investigated for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA). MRSA carriage was found in 10 (8.9%) of 112 patients in the first year and four (3.9%) of 103 patients in the second year. All isolated MRSA samples carried staphylococcal cassette chromosome mec type II or III and classified as clonal complex 5, which were common as healthcare-associated strains. Pulsed-field gel electrophoresis indicated horizontal transmission limited to two pairs of patients in one session. One of 54 healthcare workers carried MRSA genetically unrelated to patients' strains. Infection control measures based on the US Centers for Disease Control and Prevention's recommendation showed limited spread of MRSA in a haemodialysis room.

Topics: Asian People; Carrier State; Disease Transmission, Infectious; Electrophoresis, Gel, Pulsed-Field; Humans; Infection Control; Japan; Methicillin-Resistant Staphylococcus aureus; Nose; Renal Dialysis; Staphylococcal Infections

The increased incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in equine hospitals highlights the need for infection control protocols based on optimal patient screening. In horses, the deep ventral meatus of the nasal cavity is the principal site sampled to detect MRSA. However, in humans, the anterior nares are the preferred sampling site. The objective of this study was to determine the optimal sampling location in the nasal chambers for MRSA in horses by comparing the results obtained from three different locations (the vestibulum, diverticulum and ventral meatus) in 240 hospitalised animals. Antimicrobial susceptibility testing and epidemiological typing were conducted on representative subsets of the isolates obtained. Compared to the more invasive ventral meatus sampling (relative sensitivity 68.9%; isolation rate 37.9%), vestibulum (RS 81.1%; IR 44.6%, P=0.13) and diverticulum (RS 52.3%; IR 28.8%, P=0.03) sampling were more or less sensitive, respectively. In total, 132 horses (55%) were MRSA positive with the vast majority (98.5%) carrying genotyped isolates of the livestock-associated (LA)-MRSA clonal complex (CC) 398, and only a minority (1.5%) CC8. Of the 22 MLST typed isolates, five belonged to a novel ST2197 (t011, CC398). Although 93.9% of the isolates were multi-resistant (to β-lactam, tetracycline, trimethoprim, and gentamicin), <5% were resistant to virtually all antimicrobials commonly used in equine medicine. The study findings indicate that detection of MRSA in horses may be enhanced by replacing the traditional deep sampling of the ventral nasal meatus by the less invasive approach of sampling the nasal vestibulum.

Topics: Animals; Genotype; Horse Diseases; Horses; Hospitals, Animal; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections

The anterior nares of humans are the major reservoir for Staphylococcus aureus colonization. Approximately 20% of the healthy human population is persistently and 80% is intermittently colonized with S. aureus in the nasal cavity. Previous studies have shown a strong causal connection between S. aureus nasal carriage and increased risk of nosocomial infection, as well as increased carriage due to immune dysfunction. However, the immune responses that permit persistence or mediate clearance of S. aureus on the nasal mucosa are fundamentally undefined. In this study, we developed a carriage model in C57BL/6J mice and showed that clearance begins 14 days postinoculation. In contrast, SCID mice that have a deficient adaptive immune response are unable to eliminate S. aureus even after 28 days postinoculation. Furthermore, decolonization was found to be T cell mediated but B cell independent by evaluating carriage clearance in T-cell receptor β/δ (TCR-β/δ) knockout (KO) and IgH-μ KO mice, respectively. Upregulation of the cytokines interleukin 1β (IL-1β), KC (also termed CXC ligand 1 [CXCL1]), and IL-17A occurred following inoculation with intranasal S. aureus. IL-17A production was crucial for clearance, since IL-17A-deficient mice were unable to effectively eliminate S. aureus carriage. Subsequently, cell differential counts were evaluated from nasal lavage fluid obtained from wild-type and IL-17A-deficient colonized mice. These counts displayed IL-17A-dependent neutrophil migration. Antibody-mediated depletion of neutrophils in colonized mice caused reduced clearance compared to that in isotype-treated controls. Our data suggest that the Th17-associated immune response is required for nasal decolonization. This response is T cell dependent and mediated via IL-17A production and neutrophil influx. Th17-associated immune responses may be targeted for strategies to mitigate distal infections originating from persistent S. aureus carriage in humans.

Topics: Animals; B-Lymphocytes; Carrier State; Gene Expression Regulation, Bacterial; Humans; Interleukin-17; Interleukin-23; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Nose; Staphylococcal Infections; Staphylococcus aureus; T-Lymphocytes

Since 2003, a new clade of methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex (CC) 398 and associated with animal husbandry has emerged in the Netherlands. The purpose of this study was to determine the dynamics of carriage in persons with direct contact to livestock.. A 2-year prospective cohort study was performed in which the anterior nares and oropharynx of 137 livestock veterinarians were sampled for the presence of S. aureus every 4 months during the first year and again 1 year later. All S. aureus isolates were genotyped by staphylococcal protein A (spa) typing and with multilocus variable-number tandem repeat analysis (MLVA).. The mean prevalence of MRSA CC398 carriage was 44% (range, 42%-46%), and for S. aureus the prevalence was 72% (range, 69%-75%). Thirty-two veterinarians (23%) were always carrying MRSA CC398 and 18 of those (56%, 13% of all veterinarians) had identical MLVA types at all sampling moments.. A high proportion of veterinarians had persistent MRSA CC398 carriage during the 2-year study period, indicating that this variant may colonize humans for prolonged periods. Furthermore, prevalence of S. aureus carriage was extremely high, indicating that MRSA CC398 is not replacing the susceptible strains, but comes on top of it.

Topics: Adult; Animal Husbandry; Animals; Carrier State; Cohort Studies; Female; Genotype; Humans; Livestock; Male; Middle Aged; Minisatellite Repeats; Molecular Typing; Netherlands; Nose; Occupational Exposure; Oropharynx; Prevalence; Prospective Studies; Staphylococcal Infections; Staphylococcal Protein A; Staphylococcus aureus; Veterinarians

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of infections. It is well recognized that nasal carriage of S. aureus represents a potent and increasingly prevalent risk factor for subsequent S. aureus infection. However, in Madagascar no data exist concerning this nasal carriage of S. aureus.. Nasal swabs from 304 different patients attending the Laboratory of Training and Research in Medical Biology of Madagascar were cultured for methicillin sensitive (MSSA) and MRSA.. One hundred and sixteen patients had S. aureus in their noses (38.16 ± 5.46%) of whom 45 (14.80 ± 3.99%) had MRSA.  A risk factor for MSSA nasal carriage included a history of hospitalization when antibiotics were administered (odds ratio [OR] 2.25, 1.09 - 4.64). Among MRSA nasal isolates, high rate of resistance to other antibiotics was observed, particularly for trimethoprim-sulfamethoxazole (68.89%), erythromycin (66.67%) and ofloxacin (53.33%).. Our data showed a high rate of MRSA nasal carriage and a high rate of multidrug resistance. A strategic policy against the spread of multidrug resistant strains is desirable.

Topics: Adolescent; Adult; Carrier State; Confidence Intervals; Drug Resistance, Multiple, Bacterial; Erythromycin; Female; Hospitalization; Humans; Madagascar; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Ofloxacin; Prevalence; Risk Factors; Staphylococcal Infections; Surveys and Questionnaires; Trimethoprim, Sulfamethoxazole Drug Combination; Young Adult

The prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization among Emergency Medical Services (EMS) personnel is not well studied. Methicillin-resistant Staphylococcus aureus colonization can be a health hazard for both EMS personnel and patients. The aim of this study was to quantify the prevalence of MRSA colonization among EMS personnel. This study will help the scientific community understand the extent of this condition so that further protocols and policies can be developed to support the health and wellbeing of EMS personnel. Hypothesis/ Problem The hypothesis of this study was that the prevalence of MRSA colonization among EMS personnel is significantly higher than among the general population.. This was a cross-sectional study. A total of 110 subjects were selected from two major US Mid-Atlantic fire departments. Methicillin-resistant Staphylococcus aureus colonization was detected by nasal swabbing. Nasal swabs were inoculated onto a special agar medium (C-MRSAgar) with polymerase chain reaction testing performed. One-sided binomial distribution at the Study Size 2.0 Web calculator was used. Using the Web calculator, p (H0 proportion) = 1.5%; a difference (H1-H0) 'Δ' = 4.53% can be detected at α = 5% and power = 80% with N = 110.. Samples were collected from 110 volunteers. Seven samples were positive for MRSA, resulting in a prevalence of 7/110 or 6.4% (95% CI, 1.8%-11%; P < .0003) compared with a 1.5% prevalence of MRSA colonization among the general population.. There is evidence that EMS personnel have a higher prevalence of MRSA colonization than the general population. This can be a risk to patients and can be recognized as an occupational hazard.

Topics: Cross-Sectional Studies; Emergency Medical Technicians; Humans; Infectious Disease Transmission, Patient-to-Professional; Infectious Disease Transmission, Professional-to-Patient; Methicillin-Resistant Staphylococcus aureus; Mid-Atlantic Region; Nose; Occupational Diseases; Polymerase Chain Reaction; Prevalence; Staphylococcal Infections

Staphylococcus aureus is a major cause of healthcare associated mortality, but like many important bacterial pathogens, it is a common constituent of the normal human body flora. Around a third of healthy adults are carriers. Recent evidence suggests that evolution of S. aureus during nasal carriage may be associated with progression to invasive disease. However, a more detailed understanding of within-host evolution under natural conditions is required to appreciate the evolutionary and mechanistic reasons why commensal bacteria such as S. aureus cause disease. Therefore we examined in detail the evolutionary dynamics of normal, asymptomatic carriage. Sequencing a total of 131 genomes across 13 singly colonized hosts using the Illumina platform, we investigated diversity, selection, population dynamics and transmission during the short-term evolution of S. aureus.. We characterized the processes by which the raw material for evolution is generated: micro-mutation (point mutation and small insertions/deletions), macro-mutation (large insertions/deletions) and the loss or acquisition of mobile elements (plasmids and bacteriophages). Through an analysis of synonymous, non-synonymous and intergenic mutations we discovered a fitness landscape dominated by purifying selection, with rare examples of adaptive change in genes encoding surface-anchored proteins and an enterotoxin. We found evidence for dramatic, hundred-fold fluctuations in the size of the within-host population over time, which we related to the cycle of colonization and clearance. Using a newly-developed population genetics approach to detect recent transmission among hosts, we revealed evidence for recent transmission between some of our subjects, including a husband and wife both carrying populations of methicillin-resistant S. aureus (MRSA).. This investigation begins to paint a picture of the within-host evolution of an important bacterial pathogen during its prevailing natural state, asymptomatic carriage. These results also have wider significance as a benchmark for future systematic studies of evolution during invasive S. aureus disease.

Topics: Adult; Asymptomatic Infections; Carrier State; Evolution, Molecular; Genome, Bacterial; Humans; INDEL Mutation; Nose; Polymorphism, Single Nucleotide; Selection, Genetic; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus

To evaluate the in vivo effectiveness of a combination treatment containing ranalexin (a natural antimicrobial peptide) and lysostaphin (an antistaphylococcal endopeptidase) for reducing nasal burden of methicillin-resistant Staphylococcus aureus (MRSA).. The community-acquired MRSA strain S. aureus NRS384 (USA300-0114) was used in the present study because it is commonly isolated from human nares and it established consistent and reproducible colonization of cotton rat nares. This model was used to evaluate the efficacy of ranalexin/lysostaphin gels (0.1%-1% w/v; administered intranasally once or once per day for 3 consecutive days) for reducing nasal MRSA burden. Control animals were administered vehicle gel only (0.5% hydroxypropyl methylcellulose) or 2% mupirocin, which is used clinically for nasal decolonization of MRSA. Nasal MRSA burden was assessed at 192 h post-inoculation, which was at least 72 h after the final treatment had been administered. An additional study assessed the efficacy of 0.1% ranalexin/lysostaphin against a mupirocin-resistant MRSA strain (MUP20), which had been selected by serial passage of S. aureus NRS384 through subinhibitory concentrations of mupirocin.. Gels containing 0.1% ranalexin/lysostaphin consistently reduced median nasal burden of MRSA to an extent similar to or greater than 2% mupirocin. Treatment with 0.1% ranalexin/lysostaphin was also effective against the MUP20 strain. There was evidence for only minimal irritancy in cotton rat nares administered three doses of 0.1% ranalexin/lysostaphin, suggesting that this agent is suitable for short-course therapy such as is employed currently for nasal decolonization with mupirocin.. Ranalexin/lysostaphin could serve as an alternative to mupirocin for nasal decolonization of MRSA.

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Bacterial Load; Carrier State; Drug Therapy, Combination; Gels; Lysostaphin; Methicillin-Resistant Staphylococcus aureus; Models, Animal; Nose; Peptides, Cyclic; Sigmodontinae; Staphylococcal Infections; Treatment Outcome

Staphylococcus aureus nasal carriage is a common source of nosocomial infection and colonization. The aim of the present study was to assess the burden of methicillin-resistant S. aureus nasal carriage, its association with factors of interest including its genetic relationships. The prevalence of S. aureus nasal carriage was found to be 28.7%. This study showed that patients with a history of previous antibiotic intake, nasogastric tube, and longer hospitalization had a significantly high risk of being MRSA nasal carriers. The genetic relationship of all 34 nasal MRSA isolates revealed four major clusters of isolates, and there was a relationship between MRSA isolated from inpatients and healthcare workers.

Topics: Adolescent; Adult; Carrier State; Female; Health Personnel; Humans; Inpatients; Malaysia; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Staphylococcal Infections; Young Adult

To determine the relationship between methicillin-resistant Staphylococcus aureus (MRSA) colonization density, colonization site, and probability of infection in a frequently screened cohort of intensive care unit (ICU) patients.. Patients had swab samples tested for MRSA at admission to the ICU, discharge from the ICU, and twice weekly during their ICU stay, and they were followed up for development of MRSA infection. Swab test results were analyzed to determine the proportion of patients colonized and the proportion colonized at each screening site. Hazard of MRSA infection (rate of infection per day at risk) was calculated using a Cox proportional hazards analysis, and risk factors for MRSA infection, including presence of MRSA, degree of colonization, and pattern of colonization were determined.. Among the 4,194 patient episodes, 238 (5.7%) had screening results that were positive for MRSA, and there were 34 cases of MRSA infection. The hazard ratio (HR) for developing an infection increased as more sites were colonized (HR, 3.4 for being colonized at more than 1 site compared with colonization at 1 site [95% confidence interval, 1.2-9.9]). Colonization site was predictive of developing infection (HR for nose or throat colonization compared with no colonization, 168 [95% confidence interval, 69-407]).. This study demonstrated that the hazard of developing an infection was higher when more sites were colonized and that certain sites were more predictive of infection than others. These results may be useful for predicting infection in ICU patients and may influence treatment.

Topics: Axilla; Carrier State; Critical Care; Cross Infection; Female; Groin; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Population Surveillance; Predictive Value of Tests; Prospective Studies; Risk Factors; Staphylococcal Infections

Administration of antibiotics to food animals may select for drug-resistant pathogens of clinical significance, such as methicillin-resistant Staphylococcus aureus (MRSA). In the United States, studies have examined prevalence of MRSA carriage among individuals exposed to livestock, but prevalence of multidrug-resistant S. aureus (MDRSA) carriage and the association with livestock raised with versus without antibiotic selective pressure remains unclear. We aimed to examine prevalence, antibiotic susceptibility, and molecular characteristics of S. aureus among industrial livestock operation (ILO) and antibiotic-free livestock operation (AFLO) workers and household members in North Carolina.. Participants in this cross-sectional study were interviewed and provided a nasal swab for S. aureus analysis. Resulting S. aureus isolates were assessed for antibiotic susceptibility, multi-locus sequence type, and absence of the scn gene (a marker of livestock association).. Among 99 ILO and 105 AFLO participants, S. aureus nasal carriage prevalence was 41% and 40%, respectively. Among ILO and AFLO S. aureus carriers, MRSA was detected in 7% (3/41) and 7% (3/42), respectively. Thirty seven percent of 41 ILO versus 19% of 42 AFLO S. aureus-positive participants carried MDRSA. S. aureus clonal complex (CC) 398 was observed only among workers and predominated among ILO (13/34) compared with AFLO (1/35) S. aureus-positive workers. Only ILO workers carried scn-negative MRSA CC398 (2/34) and scn-negative MDRSA CC398 (6/34), and all of these isolates were tetracycline resistant.. Despite similar S. aureus and MRSA prevalence among ILO and AFLO-exposed individuals, livestock-associated MRSA and MDRSA (tetracycline-resistant, CC398, scn-negative) were only present among ILO-exposed individuals. These findings support growing concern about antibiotics use and confinement in livestock production, raising questions about the potential for occupational exposure to an opportunistic and drug-resistant pathogen, which in other settings including hospitals and the community is of broad public health importance.

Topics: Adolescent; Adult; Animals; Anti-Bacterial Agents; Carrier State; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Female; Humans; Livestock; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; North Carolina; Nose; Poultry; Prevalence; Staphylococcal Infections; Swine

The objective of this study was to investigate the dynamics of nasal carriage by Staphylococcus aureus (SA) and Staphylococcus pseudintermedius (SP) among healthy dog-owning household members involved in 7 previous index cases of suspected anthropozoonotic (n = 4) and zoonotic (n = 3) interspecies transmission [4 direct cases, identical SA (n = 3) or SP (n = 1) in owner and dog; three indirect, SP in owner (n = 2) or SA in dog (n = 1)]. Co-carriage with methicillin-resistant coagulase-negative staphylococci (MRCoNS) was also evaluated. Sixteen owners and 10 dogs were sampled once every three months for one year. In total, 50 SA and 31 SP were analysed by MLST, and SA also by spa typing. All isolates were subjected to ApaI/SmaI-PFGE and antimicrobial resistance and virulence profiles were determined. All index owners were persistent SA carriers in all direct-anthropozoonotic transmission cases, while only one dog was persistent SA carrier. Owner and dog exhibited a persistent SP carriage status in the direct-zoonotic transmission case. SP was maintained in the index human over time in one indirect-zoonotic transmission case. Only one SP was methicillin-resistant. SA belonged to genetic backgrounds of MRSA pandemic clones: CC45, CC121, CC30, CC5 and CC398. Three individuals carried a MSSA t1451-ST398 clone with the erm(T)-cadD/cadX resistance genes. SA or SP were persistently detected in the nasal cavity of 7 (43.8%) and 2 (12.5%) owners, and in one and 2 dogs, respectively. SA was recovered as the single species in 10 owners and in one dog; SP in 3 owners and 4 dogs; and both bacterial species in one owner and 4 dogs. Co-carriage of SA or SP with MRCoNS isolates was common (30.7%). This is the first study on the dynamics of nasal carriage of SA and SP in healthy pet-owning household members. Dog-contact may play a role in the staphylococcal species distribution of in-contact individuals.

Topics: Adult; Aged; Animals; Carrier State; Dogs; Drug Resistance, Bacterial; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Multilocus Sequence Typing; Nose; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus; Virulence Factors

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. Malta is one of the countries with the highest MRSA prevalence in Europe, as identified from hospital blood cultures [1]. However, community prevalence of MRSA has never previously been investigated. This study aimed at establishing the prevalence of community MRSA nasal colonization in Maltese individuals and identifying the clonal characteristics of the detected isolates. Nasal swabs were collected from 329 healthy individuals who were also asked to complete a brief questionnaire about risk factors commonly associated with MRSA carriage and infection. The swabs were transported and enriched in a nutrient broth supplemented with NaCl. The presence of MRSA was then determined by culturing on MRSA Select chromogenic agar and then confirming by several assays, including catalase, coagulase and PBP2a agglutination tests. The isolates were assayed for antibiotic susceptibilities and typed by microarray analysis to determine the clonal characteristics of each strain. The prevalence of MRSA nasal colonization in the healthy Maltese population was found to be 8.81% (95% confidence interval [CI], 5.75-11.87%), much higher than that found in other studies carried out in several countries. No statistical association was found between MRSA carriage and demographics or risk factors; however, this was hindered by the small sample size. Almost all the isolates were fusidic-acid resistant. The majority were found to belong to a local endemic clone (CC5) which seems to be replacing the previously prevalent European clone UK-EMRSA-15 in the country. A new clone (CC50-MRSA-V) was also characterized. The presence of such a significant community reservoir of MRSA increases the burdens already faced by the local healthcare system to control the MRSA epidemic. Colonization of MRSA in otherwise healthy individuals may represent a risk for endogenous infection and transmission to hospitalized patients after admission to a healthcare facility, leading to longer hospital stays and, consequently, increased healthcare costs.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Cross Infection; Female; Humans; Male; Malta; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Staphylococcal Infections; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) infections are an increasing problem, and current treatment options are suboptimal. Nasal carriage of MRSA is a major risk factor for infection, but nasal eradication strategies are increasingly considered to be insufficiently effective. In this study, a water-in-oil cream formulation was developed for nasal application with an antimicrobial peptide, P60.4Ac, aimed at the eradication of MRSA carriage. Quality control of the cream included the measurement of the content and release of the peptide by a validated high-performance liquid chromatography method. Stability of the peptide in the formulation was investigated including the evaluation of the effect of stress conditions. Preliminary shelf-life study of the drug formulation demonstrated that the peptide is stable in the formulation at least for 5 months. Microbial-killing assays with MRSA LUH14616 as a target demonstrated the dose-dependent antimicrobial activity of the peptide formulation.

Topics: Administration, Intranasal; Anti-Infective Agents; Chemistry, Pharmaceutical; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Oils; Ointments; Peptides; Staphylococcal Infections; Water

The aim of the study was a comparison of the MIC (minimal inhibitory concentration) evaluated in the automatic system Vitek 2 and the real MIC of vancomycin by the Etest method for S. aureus strains isolated from clinical materials.. Over a twelve-month study period we compared the results obtained with two commercial methods - the automatic system VITEK 2 and the real MIC by Etest - for 359 strains of S. aureus isolated from clinical materials.. Most of the strains of S. aureus were cultured from wounds (84), the ear (60) and nose (42). MSSA (methicillin-sensitive Staphylococcus aureus) was isolated in 342 cases and MRSA (methicillin-resistant Staphylococcus aureus) in 17 cases. The test with the Vitek automatic method showed that vancomycin had MIC values of ≤1.0 μg/ml in more than 96% and 2.0 μg/ml in over 3% of cases. Using the Etest technique MIC ≤ 1.0 μg/ml was obtained in only 16.4% of cases and values of >1.0 μg/ml in 83.6% of cases.. In view of such big differences between the MIC values obtained with the two methods the authors suggest that the Etest method of assaying the real MIC is more useful than the automatic method.

Topics: Anti-Bacterial Agents; Humans; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Reproducibility of Results; Staphylococcal Infections; Staphylococcus aureus; Vancomycin; Wounds and Injuries

Topics: Groin; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections

to determine the rate of MRSA-carrier among patients, family members and health care providers, and the association between MRSA-carrier family members and health care providers on MRSA infection patient after orthopaedic surgery.. this is a cross-sectional analytical study. Samples were taken consecutively during December 2010 to December 2011, consisting of postoperative patients infected with MRSA, attending family members, and the medical officers with history of contact with the patient. Swab culture were taken from nasal and axilla of all subjects. The incidence of MRSA infection, and MRSA-carrier on the patient, family members and medical officers were presented descriptively, while their association with MRSA infection was statistically tested using Fischer exact test.. during the study period, there were 759 surgeries, with 4 (0.5%) patients were identified to have MRSA infection. Of these four cases, 48 subjects were enrolled. The rate of MRSA-carrier among patients, family and health care providers were 50%, 25% and 0% respectively. There were no significant association between MRSA and the rates of MRSA-carrier on the family member or health care providers.. the incidence of MRSA infection, MRSA-carrier patient, MRSA-carrier health care providers, and family member carrier were 0.5%, 50%, 0%, and 25% respectively. No significant association found between MRSA-carrier on the family member or health care providers and MRSA infection patient. There were no MRSA infection found on the health care provider.

Topics: Axilla; Carrier State; Cross Infection; Cross-Sectional Studies; Family; Female; Humans; Indonesia; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Nurses; Orthopedic Procedures; Physicians; Staphylococcal Infections; Surgical Wound Infection

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anal Canal; Axilla; Bacterial Load; Carrier State; Female; Groin; Hospitals; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Polymerase Chain Reaction; Staphylococcal Infections; Young Adult

This retrospective study analysed the diagnostic yield of single-site, two-site, and three-site anatomical surveillance cultures in a population of 4,769 patients at high risk for methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Cultures of seven anatomical sites were used as the gold standard against which to measure the sensitivity of MRSA detection. Detection rates for the seven single-sites, 21 two-site, and 35 three-site combinations are presented. Single-site swabbing only detected 50.5% (nose) of total cases, while three-site surveillance achieved a 92% (groin + nose + throat) sensitivity of detection at best. It is recommended that at least three anatomical sites should be screened for MRSA colonisation in these high-risk patients.

Topics: Axilla; Carrier State; Female; Groin; Hospitals; Humans; Infection Control; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Readmission; Perineum; Pharynx; Population Surveillance; Retrospective Studies; Staphylococcal Infections; Umbilicus; Wales

Staphylococcus aureus is an important cause of cardiac surgical site infection. Based on studies in adults, nasal screening to detect S aureuscolonization is used to guide decolonization and selection of prophylactic antibiotics. In our Children's Hospital, a sensitive polymerase chain reaction (PCR)-based assay is used to screen patients undergoing cardiac surgery for nasal colonization with methicillin-sensitive S aureus (MSSA) and methicillin-resistant S aureus (MRSA). Additionally for patients in diapers, cultures are used to detect MRSA colonization of the groin. The purpose of this study was to determine whether screening two anatomic locations results in a higher MRSA detection rate among children undergoing cardiac surgery.. A retrospective chart review determined whether the frequency of bacterial colonization with MRSA differed by anatomic site. Records for 322 pediatric cardiac surgery procedures performed between January 2009 and June 2011 were reviewed. Both a nasal PCR and a second anatomic site culture were performed before 102 procedures.. The overall rate of colonization with MRSA and MSSA was 4.2% and 29.1%, respectively. Of the seven dually screened patients who tested positive for MRSA, two were identified solely via a groin test, four by nasal screening alone, and one by both the tests. Screening of only the nose would have failed to detect 28.6% of the MRSA cases.. Preoperative detection of MRSA colonization may be enhanced by screening both the nose and a second anatomic site. The clinical utility of the extranasal MRSA culture was limited due to the long assay turnaround time.

Topics: Cardiac Surgical Procedures; Child; Child, Preschool; Cross Infection; Early Diagnosis; Female; Groin; Heart Defects, Congenital; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Preoperative Care; Staphylococcal Infections; Surgical Wound Infection

Acquisition of nasal Staphylococcus aureus (S. aureus) colonization by contaminated hands is likely an important determinant of its nasal carriage rate in health care and lab setting. The objective of our cross-sectional study was to assess the prevalence of nasal methicillin-sensitive (MSSA) or -resistant Staphylococcus aureus (MRSA) carriage among health care professionals (HCPs) attending an international symposium and to study the association between compliance with hygiene rules, individual-related parameters, and medical conditions with nasal S. aureus carriage in this population. After obtaining consent, two nasal swabs were collected. Nasal MSSA and MRSA carriage was measured by the: i) molecular approach targeting spa, mecA and mecA-orfX junction sequences, and ii) culture on selective S. aureus media combined with mecA molecular detection of isolated strains. Information on compliance with hygiene rules, demographic variables, sector of activity and long-term medication was collected by anonymous questionnaire. The participation rate was 32.3%. In total, 176 subjects from 34 countries were included in the analysis. S. aureus was isolated from the nasal swabs of 57 (32.4%) subjects, of whom 3 (5.3%) harbored MRSA strains. Overall, 123 subjects reported working in microbiology laboratories with direct manipulation of S. aureus, and 29 acknowledged regular contacts with patients. In this exposed population, hydro-alcoholic solutions appeared to have a significant protective effect against nasal S. aureus carriage (OR = 0.36; 95% CI: 0.15-0.85). Hospital work was associated with increased risk of nasal S. aureus carriage (OR = 2.38; 95% CI: 1.07-5.29). The results of this study showed that compliance with basic rules of hygiene, such as the use of hydro-alcoholic solutions, could reduce the risk of nasal S. aureus colonization. Hydro-alcoholic solution could interrupt auto-transmission of the pathogen, consequently decreasing the overall nasal carriage rate, specifically in transient carriers.

Topics: Adult; Cross-Sectional Studies; Female; Health Personnel; Humans; Hygiene; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nasal Cavity; Nose; Staphylococcal Infections; Staphylococcus aureus

Methicillin-susceptible Staphylococcus aureus (MSSA) attributed to clonal complex (CC) 398 and exhibiting spa-type t571 received attention in Europe and in the USA for being associated with severe infections in humans. As this spa-type is exhibited by livestock-associated (LA) Methicillin-resistant S. aureus (MRSA) as well, it is important to discriminate LA- and human-derived strains by easy to perform, PCR-based methods. MSSA t571 contain phage int3 carrying scn and chp, whereas LA-MRSA t571 lack these markers. In contrast, pathogenicity island SaPIbov5 (detected by PCR bridging vwbbov and scn) is contained by LA-MRSA t571 and absent in the human MSSA subpopulation. Furthermore, MSSA t571 contain erm(T), the particular genomic arrangement of which was assessed by a PCR bridging erm(T) and the adjacent transposase gene. MSSA t571 are rare so far in Germany among isolates from infections in humans (0.14%) as well as among isolates from nasal colonization (0.13%). LA-MRSA t571 are also infrequent among MRSA isolated from carriage at admission to hospitals (0.1%) and also among isolates from infections in humans (0.013%).

Topics: Animals; Genetic Markers; Germany; Horses; Humans; Livestock; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Staphylococcal Infections

Healthcare workers (HCWs) may be a reservoir for Staphylococcus aureus transmission to patients. We examined whether HCW status is associated with S. aureus nasal carriage and population structure (spa types) in 1302 women (334 HCWs) and 977 men (71 HCWs) aged 30-69 years participating in the population-based Tromsø Study in 2007-2008. Multivariable logistic regression models were used. While no methicillin-resistant S. aureus (MRSA) was isolated, overall, 26·2% of HCWs and 26·0% of non-HCWs were S. aureus nasal carriers. For women overall and women residing with children, the odds ratios for nasal carriage were 1·54 [95% confidence interval (CI) 1·09-2·19] and 1·86 (95% CI 1·14-3·04), respectively, in HCWs compared to non-HCWs. Moreover, HCWs vs. non-HCWs had a 2·17 and 3·16 times higher risk of spa types t012 and t015, respectively. This supports the view that HCWs have an increased risk of S. aureus nasal carriage depending on gender, family status and spa type.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Typing Techniques; Carrier State; Female; Health Personnel; Humans; Male; Middle Aged; Norway; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Since the implementation of Streptococcus pneumoniae (SPn) conjugate vaccination (PCV), non-vaccine types have prevailed in invasive pneumococcal disease (IPD), and an increase in Staphylococcus aureus (SA) burden has been suggested. Here, we assess the epidemiology of SA and SPn nasal carriage in 620 children at day-care centres; 141 of these children had received 1-4 PCV7 doses. A higher vaccine dosage was associated with non-vaccine-type SPn carriage. Of all SPn isolates, 45% were PCV7 types, 1% were additional PCV10 types and 22% were the three additional PCV13 types. SA carriage was inversely associated with vaccine-type SPn carriage. SPn serotype 19A showed higher SA co-carriage rates compared to other SPn serotypes. PCV7 implementation does not prevent children from being part of the IPD-related SPn transmission chain. These results contribute to the monitoring of SA- and SPn-related disease and add to the debate on the current national vaccination policy that recently included a change from PCV7 to PCV10.

Topics: Age Factors; Carrier State; Child Day Care Centers; Child, Preschool; Coinfection; Cross-Sectional Studies; Humans; Infant; Netherlands; Nose; Pneumococcal Infections; Pneumococcal Vaccines; Serotyping; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae; Vaccination; Vaccines, Conjugate

Staphylococcus aureus, which has its ecological niche in the anterior nares, has been shown to cause a variety of infectious diseases mainly for patients in hemodialysis units. We performed this study to evaluate the prevalence of nasal S. aureus carriage among hemodialysis outpatients, to determine the antimicrobial susceptibility of isolates, to characterize the virulence genes, and to identify associated risk factors. Nares swab specimens were obtained from 70 outpatients on hemodialysis between March and June 2010. Samples were plated immediately onto S. aureus specific media and pattern of antibacterial sensitivity was determined using disk diffusion method. Polymerase chain reaction was used to detect nuc, mecA, and genes encoding staphylococcal toxins. Medical record of patients was explored to determine S.aureus carriage risk factors. Nasal screening identified 42.9% S. aureus carriers with only one (3.3%) methicillin-resistant S. aureus isolate. Among the methicillin-susceptible S. aureus isolates, high rate of penicillin resistance (81.8%) has been detected. The identified risk factors were male gender and age ≤ 30 years. Research of virulence factors showed a high genetic diversity among the 30 S. aureus isolates. Twenty-one (70%) of them had at least one virulence gene, of which 3.3% were Panton-Valentine leukocidin (lukS/F-PV) genes. S. aureus carriage must be screened for at regular intervals in hemodialysis patients. Setting up a bacterial surveillance system is one of the strategies to understand the epidemiology of methicillin-resistant S. aureus, to guide local antibiotic policy and prevent spread of antibiotic-resistant S. aureus.

Topics: Cohort Studies; Female; Humans; Male; Middle Aged; Morocco; Nose; Prospective Studies; Renal Dialysis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

There are few data on meticillin-resistant Staphylococcus aureus (MRSA) screening in obstetrics, a largely healthy population that should be at lower risk for MRSA than most hospitalized populations. From January 2009 to December 2011 nose swabs were screened from 5548 of 21,770 (25.5%) women who delivered at Birmingham Women's Hospital. Only 29 (0.5%) were MRSA positive: MRSA infections occurred later in three cases. MRSA infections occurred in a further 13 mother-infant pairs, including six cases where mothers were MRSA screen negative. Seventeen mothers had risk factors for MRSA. MRSA is not widespread in obstetrics, and large-scale screening of nasal swabs is of limited value in preventing MRSA-related morbidity in this population.

Topics: Carrier State; Female; Humans; Infant, Newborn; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Obstetrics and Gynecology Department, Hospital; Pregnancy; Prevalence; Risk Factors; Staphylococcal Infections

MRSA CC5 spa type t002 appears to have a broad host range, has been isolated from animals and in-contact humans in Ireland and could potentially become established in pigs in Ireland. The aims of this study were to determine if MRSA CC5 spa type t002 could persist in the tissues of the porcine upper respiratory tract following intra-nasal inoculation; to determine the relative importance of environmental and animal sources of the bacterium in the transmission cycle and to determine the importance of the pharynx as a carriage site of Staphylococcus aureus and MRSA. Twelve pigs were inoculated intra-nasally with MRSA CC5 t002. After 1 or 6 days, the inoculated pigs were removed from the contaminated environment, were washed in an antiseptic solution and placed in a clean house with a group of naive pigs (in-contact group). Another group of naive pigs was placed in the contaminated environment to assess transmission from the environment (environmental group). Nasal swabs, environmental swabs and tissue samples from the upper respiratory tract were taken for MRSA culture. Infection rates were calculated for each group of exposed pigs. MRSA persisted in the pharyngeal tissues of 6 inoculated pigs for at least 30 days and higher counts of S. aureus were found in pharyngeal tissues than in other sites. In this study we were able to demonstrate the establishment of colonisation by MRSA CC5 spa type t002 in commercially sourced pigs already colonised by S. aureus; however, colonisation was sporadic despite the inoculation of large doses. Onward transmission via pig-to-pig contact or environmental contamination was possible and a significant difference was found between the proportion of pigs infected in the environmental group and the proportion infected in the in-contact group during the first 5 days. However, no significant difference was detected in overall infection rates between the 2 groups. The tissues of the pharynx were found to carry greater numbers of S. aureus than other tissues of the upper respiratory tract; therefore, pharyngeal carriage of MRSA and S. aureus in pigs may be more significant than previously thought.

Topics: Animals; Humans; Ireland; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Sus scrofa; Swine; Swine Diseases

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired and life-threatening infections. Active surveillance programs for MRSA utilize either molecular or culture-based methods. A prospective study was performed to compare the performance of selective and differential chromogenic media, BBL CHROMagar MRSA II (CMRSA II; BD Diagnostics, Sparks, MD), MRSASelect (Bio-Rad Laboratories, Redmond, WA), and Spectra MRSA (Remel, Lenexa, KS), for the detection of MRSA in nasal swab specimens. A total of 515 compliant remnant nasal swab specimens were sequentially used to inoculate BBL Trypticase soy agar with 5% sheep blood (TSA II) and each chromogenic medium. After 24 h of incubation, colony color reactions and morphology on chromogenic media were compared to suspicious colonies on nonselective TSA II. MRSA on TSA II was confirmed by Gram staining, a coagulase test, and a cefoxitin disk test. The overall prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) on TSA II was 12.4% (64/515) and 9.7% (50/515), respectively. When each chromogenic medium was compared to the standard culture method, the sensitivity and specificity, respectively, were as follows: CMRSA II, 87.7% and 98.6%; MRSASelect, 89.0% and 93.4%; and Spectra MRSA, 83.6% and 92.1%. The positive predictive values were highest for CMRSA II (91.4%), followed by MRSASelect (69.1%) and Spectra MRSA (63.5%). False-positive results on chromogenic media were mainly due to color interpretation. The negative predictive values for all three media were greater than 97%. In conclusion, CMRSA II gave the best overall results for detecting MRSA from nasal specimens.

Topics: Bacteriological Techniques; Carrier State; Chromogenic Compounds; Color; Culture Media; False Positive Reactions; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Staphylococcal Infections; Time Factors

The anterior nares are the site of choice for the Veterans Administration methicillin-resistant Staphylococcus aureus (MRSA) surveillance program; however, a correlation between nares colonization and concomitant wound infections has not been well established. The purpose of this study was 3-fold: to determine the relatedness of MRSA isolates from 40 paired wound and nares specimens by four different strain typing methods, to determine concordance of typing methods, and to establish a baseline of MRSA types at this medical center. Isolates were typed by repetitive PCR (rep-PCR) (DiversiLab System; DL) and SpectraCell Raman analysis (SCRA) (commercially available methods that can be performed within a clinical lab), pulsed-field gel electrophoresis (PFGE), and an antibiotic susceptibility profile (AB). Whole-genome optical mapping (WGM) (OpGen, Inc.) was performed on selected isolates. All methods agreed that 26 pairs were indistinguishable and four pairs were different. Discrepant results were as follows: 4 where only SCRA was discordant, 3 where only AB was discordant, 2 where both DL and AB were discordant, and 1 where both DL and SCRA were discordant. All WGM agreed with PFGE. After discrepancy resolution, 80% of the pairs were indistinguishable and 20% were different. A total of 56% of nares results were nonpredictive if negative nares and positive wound cultures are included. Methods agreed 85 to 93% of the time; however, congruence of isolates to a clade was lower. Baseline analysis of types showed that 15 pairs were unique to single patients (30 strains, 38%; 47% of the matching pairs). Twenty-five strains (30%) represented a single clade identical by PFGE, SCRA, and DL, decreasing specificity. Typing method and institutional type frequency are important in assessing MRSA strain relatedness.

Topics: Bacterial Typing Techniques; Hospitals, Veterans; Humans; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Nose; Staphylococcal Infections; Wound Infection; Wounds and Injuries

The performance of the Xpert MRSA polymerase chain reaction (PCR) assay on pooled nose, groin, and throat swabs (three nylon flocked eSwabs into one tube) was compared to culture by analyzing 5,546 samples. The sensitivity [0.78, 95 % confidence interval (CI) 0.73-0.82] and specificity (0.99, 95 % CI 0.98-0.99) were similar to the results from published studies on separated nose or other specimens. Thus, the performance of the Xpert MRSA assay was not affected by pooling the three specimens into one assay, allowing a higher detection rate without increasing laboratory costs, as compared to nose samples alone.

Topics: Bacteriological Techniques; Carrier State; Costs and Cost Analysis; Groin; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Pharynx; Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections

Genetically determined variation in the expression of innate defense molecules may explain differences in the propensity to be colonized with Staphylococcus aureus.. We determined S. aureus nasal carriage in 603 volunteers; analyzed polymorphisms in the DEFB1 promoter at positions -52 G>A (rs1799946), -44 C>G (rs1800972), and -20 G>A (rs11362); and measured the content of human β-defensin 1 (hBD-1) and hBD-3 messenger RNA (mRNA) in 192 samples of healthy and experimentally wounded human skin.. Compared with GGG at the positions -52/-44/-20, the ACG haplotype was more common among persistent S. aureus nasal carriers (odds ratio, 1.93; 95% confidence interval [CI], 1.2-3.1; P = .006) and was associated with reduced expression of hBD-1 (GGG>ACG>GCA; P < .001) and hBD-3 (GGG>GCA>ACG; P = .04) in skin when measured 72 hours after wounding. Furthermore, a 50% decrease in hBD-1 and hBD-3 mRNA expression in wounded skin increased the odds of persistent carriage by 1.45 (95% CI, .93-2.26; P = .1) and 1.48 (95% CI, 1.01-2.17; P = .04), respectively. Adjustment for known risk factors of persistent S. aureus carriage did not substantially change the associations of both DEFB1 haplotypes and β-defensin expression with S. aureus colonization.. DEFB1 polymorphisms may promote persistent S. aureus colonization by altering β-defensin expression in keratinocytes of human skin.

Topics: Adult; beta-Defensins; Carrier State; Cross-Sectional Studies; Down-Regulation; Female; Genetic Association Studies; Host-Pathogen Interactions; Humans; Keratinocytes; Male; Nose; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Skin; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To optimize preventive measures to control MRSA, we investigated retrospectively the suitability of a multiple site screening model and the optimal sampling technique to detect MRSA in a university-based phlebology and skin cancer center in Germany.. During 4.5 years samples of 3 712 inpatients in a dermatologic department were analyzed for MRSA by conventional microbiologic cultures and in parallel by PCR. Samples were taken from nares, wounds and skin lesions.. MRSA was detected in 60 inpatients (1.6%). 268 of 7 269 (3.7%) samples at admission and during hospital stay were found positive ñ 96 (35.8%) of these were swabs of nares, 59 (22.0%) surveillance swabs, 53 (19.8%) wound swabs and 42 (15.7%) from other dermatologic lesions. Twenty-five of 60 patients (41.7%) were found positive only in the nares, 10 (16.7%) patients only in wounds and 4 (6.7%) patients only in lesions. 166 (61.9%) of all positive culture samples became positive 24 hours after cultivation, 86 (32.1%) after 48 hours, and 16 (6.0%) after 72 hours.. Highest sensitivity to detect MRSA can be reached by combining three swabs: nares, wounds and skin lesions (ìtriple-testî). Culture of screening specimens for 72 hours is recommended.

Topics: Academic Medical Centers; Cross Infection; Germany; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Reproducibility of Results; Risk Assessment; Risk Factors; Sensitivity and Specificity; Soft Tissue Infections; Staphylococcal Infections; Tertiary Care Centers

Staphylococcus aureus remains a significant cause of morbidity and mortality and, therefore, a burden on healthcare systems. Our aim was to estimate the current rate of nasal S. aureus carriage in the general population and to determine the feasibility of nasal self-swabbing as a means of detection. Two thousand people (1200 adults and 800 children) from a single NHS general practice in Southampton, UK, were randomly selected from a general practice age sex register, stratified by age and sex, and invited to undertake nasal self-swabbing in their own home. Overall, 362 (32.5%) swabs from adults and 168 (22%) from children were returned. Responses were greater for adults and those of increased age, female gender and decreasing socio-economic deprivation. The overall estimated practice carriage rate of S. aureus directly standardized for age sex was 28% [95% confidence interval (CI) 26.1-30.2%]. Carriage of meticillin-susceptible S. aureus was 27% (95% CI 26.1-30.2%), whilst that of meticillin-resistant S. aureus was 1.9% (95% CI 0.7-3.1%). Although nasal self-swabbing rates were relatively low, they are comparable to other studies and may allow large population-based carriage studies to be undertaken at relatively low cost. Importantly, this study updates prevalence data for S. aureus carriage in the community.

Topics: Adolescent; Adult; Aged; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Middle Aged; Nose; Population Surveillance; Prevalence; Self Care; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Staphylococcus aureus is the main cause of diabetic foot infection with the patient's endogenous flora as the principal source. Nasal carriage of S. aureus has been identified as an important risk factor for the acquisition of diabetic foot infections.. The study assessment the associations of S. aureus with methicillin resistant S. aureus were isolation from diabetic foot infection and nasal carriage of the same patients and their antibiotic susceptibility profile.. Diagnosis of S. aureus and methicillin resistant S. aureus were carried out by using standard procedures. Antibiotic sensitivity profiles were determent by breakpoint dilution method.. Out of 222 S. aureus isolation, 139 (62.61%) were isolated from the diabetic foot and 83 (37.39%) from the nasal carriage. Seventy one (30.87%) of the patients were S. aureus infection diabetic foot with nasal carriage. Among diabetic foot infection and nasal carriage patients, 40.85% of S. aureus were considered as methicillin resistant S. aureus. Rifampicin (96.40%) and Levofloxacin (91.44%) were active against S. aureus.. Patients at strong risk for methicillin resistant S. aureus nasal carriage and subsequent diabetic foot infection with high resistance to antibiotics.

Topics: Adult; Aged; Anti-Bacterial Agents; Carrier State; Diabetic Foot; Female; Humans; Levofloxacin; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Ofloxacin; Rifampin; Risk Factors; Staphylococcal Infections

The epidemic of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has had a disproportionate impact on patients with human immunodeficiency virus (HIV).. We evaluated CA-MRSA colonization burden (number of colonized sites per total number sampled) among HIV-infected and HIV-negative inpatients within 72 hours of hospitalization. From March 2011 through April 2012, we obtained cultures from nasal and extranasal sites (throat, axilla, inguinal, perirectal, and chronic wound if present) and collected risk factor data.. Of 745 patients (374 HIV-infected, 371 HIV-negative), 15.7% were colonized with CA-MRSA at any site: 20% of HIV and 11% of HIV-negative patients (relative prevalence=1.8, P=.002). HIV-infected patients had a higher prevalence of nasal, extranasal, and exclusive extranasal colonization as well as higher colonization burden. Perirectal and inguinal areas were the extranasal sites most frequently colonized, and 38.5% of colonized patients had exclusive extranasal colonization. Seventy-three percent of isolates were identified as USA300. Among HIV-infected patients, male sex, younger age, and recent incarceration were positively associated whereas Hispanic ethnicity was negatively associated with higher colonization burden. Among HIV-negative patients, temporary housing (homeless, shelter, or substance abuse center) was the only factor associated with higher colonization burden. Predictors of USA300 included HIV, younger age, illicit drug use, and male sex; all but 1 colonized individual with current or recent incarceration carried USA300.. HIV-infected patients were more likely to have a higher CA-MRSA colonization burden and carry USA300. In certain populations, enhanced community and outpatient-based infection control strategies may be needed to prevent CA-MRSA cross-transmission and infection.

Topics: Adult; Aged; Bacterial Load; Carrier State; Community-Acquired Infections; Female; HIV Infections; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Prevalence; Prisons; Risk Factors; Staphylococcal Infections

Patterns of methicillin-resistant S. aureus (MRSA) nasal carriage over time and across the continuum of care settings are poorly characterized. Knowledge of prevalence rates and outcomes associated with MRSA nasal carriage patterns could help direct infection prevention strategies. The VA integrated health-care system and active surveillance program provides an opportunity to delineate nasal carriage patterns and associated outcomes of death, infection, and conversion in carriage.. We conducted a retrospective cohort study including all patients admitted to 5 acute care VA hospitals between 2008-2010 who had nasal MRSA PCR testing within 48 hours of admission and repeat testing within 30 days. The PCR results were used to define a baseline nasal carriage pattern of never, intermittently, or always colonized at 30 days from admission. Follow-up was up to two years and included acute, long-term, and outpatient care visits. Among 18,038 patients, 91.1%, 4.4%, and 4.6% were never, intermittently, or always colonized at the 30-day baseline. Compared to non-colonized patients, those who were persistently colonized had an increased risk of death (HR 2.58; 95% CI 2.18;3.05) and MRSA infection (HR 10.89; 95% CI 8.6;13.7). Being in the non-colonized group at 30 days had a predictive value of 87% for being non-colonized at 1 year. Conversion to MRSA colonized at 6 months occurred in 11.8% of initially non-colonized patients. Age >70 years, long-term care, antibiotic exposure, and diabetes identified >95% of converters.. The vast majority of patients are not nasally colonized with MRSA at 30 days from acute hospital admission. Conversion from non-carriage is infrequent and can be risk-stratified. A positive carriage pattern is strongly associated with infection and death. Active surveillance programs in the year following carriage pattern designation could be tailored to focus on non-colonized patients who are at high risk for conversion, reducing universal screening burden.

Topics: Aged; Carrier State; Colony Count, Microbial; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Mortality; Multivariate Analysis; New England; Nose; Polymerase Chain Reaction; Risk Factors; Staphylococcal Infections; Time Factors

Staphylococcus aureus is an opportunistic pathogen able to colonize the upper respiratory tract and skin surfaces in mammals. Methicillin-resistant S. aureus ST398 is prevalent in pigs in Europe and North America. However, the mechanism of successful pig colonization by MRSA ST398 is poorly understood. To study MRSA colonization in pigs, an ex vivo model consisting of porcine nasal mucosa explants cultured at an air-liquid interface was evaluated. In cultured mucosa explants from the surfaces of the ventral turbinates and septum of the pig nose no changes in cell morphology and viability were observed up to 72 h. MRSA colonization on the explants was evaluated followed for three MRSA ST398 isolates for 180 minutes. The explants were incubated with 3×10(8) CFU/ml in PBS for 2 h to allow bacteria to adhere to the explants surface. Next the explants were washed and in the first 30 minutes post adhering time, a decline in the number of CFU was observed for all MRSA. Subsequently, the isolates showed either: bacterial growth, no growth, or a further reduction in bacterial numbers. The MRSA were either localized as clusters between the cilia or as single bacteria on the cilia surface. No morphological changes in the epithelium layer were observed during the incubation with MRSA. We conclude that porcine nasal mucosa explants are a valuable ex vivo model to unravel the interaction of MRSA with nasal tissue.

Topics: Animals; Methicillin-Resistant Staphylococcus aureus; Nasal Mucosa; Nose; Staphylococcal Infections; Swine

The prevalence of natural carriage and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) isolates in a Jordanian community were investigated. The MRSA nasal carriage rate in 227 healthy volunteers was 7·5% and the majority (81%) of MRSA harboured the resistance element SCCmec type IVe and were of a novel spa type t9519 (76%); other significant spa gene types were t223 (14·7%) and t044 (5·9%). All MRSA isolates were susceptible to other classes of antibiotics, and tested positive for at least three virulence factor encoding genes, but only two harboured the pvl gene. MR-CoNS carriage was 54·2% and these isolates were characterized by single, double and untypable SCCmec elements, with Staphylococcus epidermidis SCCmec type IVa predominating. Of eight subjects with nasal co-colonization of MR-CoNS + MRSA, three shared SCCmec type IV in both groups of organisms. This is the first report of methicillin-resistant staphylococci carriage in a Jordanian community and its findings are important for epidemiological study and infection control measures of these organisms.

Topics: Anti-Bacterial Agents; Carrier State; DNA, Bacterial; Female; Humans; Jordan; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Skin; Staphylococcal Infections

We assessed characteristics associated with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carriage among residents of 22 nursing homes. Of MRSA-positive swabs, 25% (208/824) were positive for CA-MRSA. Median facility CA-MRSA percentage was 22% (range, 0%-44%). In multivariate models, carriage was associated with age less than 65 years (odds ratio, 1.2; P<.001) and Hispanic ethnicity (odds ratio, 1.2; P=.006). Interventions are needed to target CA-MRSA.

Topics: Age Factors; Aged; California; Carrier State; Community-Acquired Infections; Female; Hispanic or Latino; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Nursing Homes; Odds Ratio; Prevalence; Staphylococcal Infections

Staphylococcus aureus represents an organism of striking versatility. While asymptomatic nasal colonization is widespread, it can also cause serious infections, toxinoses and life-threatening illnesses in humans and animals. Staphylococcal food poisoning (SFP), one of the most prevalent causes of foodborne intoxication worldwide, results from oral intake of staphylococcal enterotoxins leading to violent vomiting, diarrhea and cramps shortly upon ingestion. The aim of the present study was to compare isolates associated with SFP to isolates collected from cases of human nasal colonization and clinical infections in order to investigate the role of S. aureus colonizing and infecting humans as a possible source of SFP. Spa typing and DNA microarray profiling were used to characterize a total of 120 isolates, comprising 50 isolates collected from the anterior nares of healthy donors, 50 isolates obtained from cases of clinical infections in humans and 20 isolates related to outbreaks of staphylococcal food poisoning. Several common spa types were found among isolates of all three sources (t015, t018, t056, t084). DNA microarray results showed highly similar virulence gene profiles for isolates from all tested sources. These results suggest contamination of foodstuff with S. aureus colonizing and infecting food handlers to represent a source of SFP.

Topics: Carrier State; Cluster Analysis; Humans; Microarray Analysis; Molecular Epidemiology; Molecular Typing; Nose; Staphylococcal Food Poisoning; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

Vitamin D induces the expression of antimicrobial peptides with activity against Staphylococcus aureus. Thus, we studied the association between serum 25-hydroxyvitamin D (25(OH)D) and S. aureus nasal colonization and carriage. Nasal swabs, blood samples and clinical data from 2,115 women and 1,674 men, aged 30-87 years, were collected in the Tromsø Staph and Skin Study 2007-08, as part of the population-based sixth Tromsø Study. Multivariate logistic regression analyses were stratified by recognized risk factors for S. aureus carriage: sex, age and smoking. In non-smoking men, we observed a 6.6% and 6.7% decrease in the probability of S. aureus colonization and carriage, respectively, by each 5 nmol/l increase in serum 25(OH)D concentration (P < 0.001 and P = 0.001), and serum 25(OH)D > 59 nmol/l and ≥75 nmol/l as thresholds for ~30% and ~50% reduction in S. aureus colonization and carriage. In non-smoking men aged 44-60 years, the odds ratio for S. aureus colonization was 0.44 (95% confidence interval, 0.28-0.69) in the top tertile of serum 25(OH)D versus the bottom tertile. In women and smokers there were no such associations. Our study supports that serum vitamin D is a determinant of S. aureus colonization and carriage.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Female; Humans; Longitudinal Studies; Male; Middle Aged; Nose; Risk Factors; Sex Factors; Smoking; Staphylococcal Infections; Staphylococcus aureus; Vitamin D

Persistent Staphylococcus aureus nasal carriers are at high risk of S. aureus infection. The present study delineates a simple strategy aimed at identifying rapidly and accurately this subset of subjects for clinical or epidemiological purposes. Ninety healthy volunteers were each identified as persistent, intermittent or non-nasal carriers of S. aureus by using seven specimens sampled over a 5-week period. By reference to this so-called reference standard, six other strategies aimed at simplifying and speeding the identification of persistent carriers and based on the qualitative or quantitative detection of S. aureus in one to three nasal samples were evaluated by the measure of the area under the curve of receiver operating characteristic diagrams. Among strategies using qualitative results, there was no statistical difference between protocols using seven and three samples. A threshold of 10(3) CFU of S. aureus per swab was found capable of defining persistent nasal carriage with a sensitivity of 83.1% and a specificity of 95.6%. These figures reached 95.5% and 94.9%, respectively, by using an algorithm including one or two nasal specimens according to the threshold of 10(3) CFU of S. aureus in the first swab. The latter two strategies were shown to be costly equivalents. The proposed algorithm-based strategy proved to be relevant to identify properly and consistently persistent nasal carriers of S. aureus. However, as it was built from data of healthy volunteers, it needs to be confirmed prospectively on patients potentially at risk for S. aureus infection.

Topics: Adult; Algorithms; Bacteriological Techniques; Carrier State; Female; Humans; Male; Middle Aged; Nose; ROC Curve; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Diabetes mellitus is a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection. We attempted to determine the prevalence and risk factors for MRSA colonization in a population of outpatients with diabetes.. This prospective cohort study enrolled patients with diabetes. Anterior nares cultures were obtained from patients with diabetes admitted to outpatient endocrinology and metabolism clinics, and risk factors for MRSA colonization were analyzed.. Out of the 304 patients evaluated, 127 (41.9%) were colonized with S aureus and 30 (9.9%) were colonized with MRSA. Overall, 23.6% of all S aureus isolates were MRSA. In multivariate analysis, factors independently associated with an increased risk of MRSA colonization included the presence of connective tissue disease (odds ratio, 7.075; 95% confidence interval, 2.157-23.209; P = .001) and insulin therapy (odds ratio, 3.910; 95% confidence interval, 1.652-9.251; P = .002).. The prevalence of MRSA colonization in our sample of diabetic outpatients was 9.9%. Independent risk factors for MRSA colonization were the presence of connective tissue disease and insulin use. A better understanding of the epidemiology and risk factors for nasal MRSA colonization in the persons with diabetes may have significant implications for the treatment and prevention of MRSA infections.

Topics: Adult; Aged; Carrier State; Cohort Studies; Diabetes Complications; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Outpatients; Prevalence; Prospective Studies; Risk Factors; Staphylococcal Infections

The purpose of this study was to assess the accuracy of the Xpert MRSA assay (XP) for the detection of methicillin-resistant Staphylococcus aureus (MRSA) carriage upon hospital admission. Nasal swabs were prospectively collected for MRSA screening from 1,891 patients admitted to a teaching hospital. XP results were compared to chromogenic agar culture results. MRSA was cultured in 61 specimens (3%). Compared with culture, XP had a sensitivity, specificity, positive, and negative predictive value of 60.7, 97.3, 37.8, and 98.9%, respectively. The median turnaround time (TAT) for the results was 3 h. Of 24 MRSA isolated from XP-negative samples, three harbored composite SCCmec. Among 61 samples with culture-negative but XP-positive results, 15 methicillin-susceptible S. aureus (MSSA) isolates tested positive by XP on pure colony lysates. These MSSA included: (i) strains with SCCmec deletion encompassing mecA and (ii) multilocus sequence typing (MLST) clonal complex (CC) 1 strains harboring a chromosomal sequence homologous to one of the orfX-SCCmec junction sequences targeted by XP. On account of the low sensitivity and positive predictive value in a hospital patient population with moderate prevalence of MRSA, culture still appears to be necessary in order to confirm polymerase chain reaction (PCR) results. The emergence of new SCCmec variants and the presence of MSSA harboring cross-reactive SCCmec-like elements may challenge the successful implementation of such detection systems.

Topics: Bacteriological Techniques; Carrier State; Diagnostic Tests, Routine; Hospitals; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Staphylococcal Infections; Time Factors

Due to a longstanding comprehensive "search and destroy policy", methicillin-resistant Staphylococcus aureus (MRSA) is not endemic in Western Australian (WA) acute care hospitals. As the prevalence of MRSA in the community has increased, healthcare workers (HCW) are at risk of importing MRSA into hospitals. We aimed to determine the prevalence of and risk factors for nasal MRSA colonization in our HCW population. A period prevalence study was conducted at an 850-bed tertiary hospital. Basic demographics and a nasal swab were obtained. A total of 1,542 HCWs employed in our centre were screened for MRSA, of whom 3.4% (n = 52) were colonized. MRSA colonization was more common in patient care assistants (6.8%) and nurses (5.2%) than in allied health professionals (1.7%) and doctors (0.7%) (p < 0.01). Working in "high-risk" wards that cared for MRSA colonized/infected patients was the strongest risk factor for HCW MRSA colonization (p < 0.001). ST1-IV and ST78-IV (the most common community clones in the region) were the most frequently identified clones. In conclusion, MRSA colonization of HCWs occurs primarily in HCWs caring for patients colonized or infected with MRSA. Surveillance screening of HCWs should be regularly performed on wards with patients with high MRSA colonization prevalence to prevent further spread in the hospital.

Topics: Adolescent; Adult; Aged; Carrier State; Female; Health Personnel; Hospitals; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Western Australia; Young Adult

Nasal carriage of methicillin-resistant coagulase-negative staphylococci (MR-CoNS) is highly prevalent in community subjects, but its dynamic has been little investigated. Nasal swabbing was performed in 2006 and 2008 in 154 Amerindians living isolated in French Guiana. MR-CoNS strains were identified and characterized by non-β-lactam susceptibility testing and staphylococcal cassette chromosome mec element (SCCmec) typing, characterizing the associations of ccr and mec gene complex allotypes, and for MR Staphylococcus epidermidis (MRSE), multilocus variable number of tandem repeats analysis (MLVA) was used. The impact of sociodemographic and medical characteristics on the persistence of MR-CoNS carriage was assessed by bivariate analysis. Prevalence of MR-CoNS carriage was 50.6% in 2006 and 46.8% in 2008. The 274 MR-CoNS isolates, including S. epidermidis (n = 89, 62 MLVA patterns), Staphylococcus haemolyticus (n = 78), and Staphylococcus hominis (n = 72), exhibited 41 distinct ccr and mec gene complex associations. Persistent carriage (in 2006 and 2008), intermittent carriage (either in 2006 or 2008), and noncarriage were documented in 25.3, 47.4, and 27.3% of the participants, respectively. Persistent carriage of a given MRSE isolate was rarely observed (n = 8 isolates). Furthermore, no epidemiological factor, including antibiotic exposure, was associated with persistent carriage. The high diversity of MRSE clones and their ccr and mec gene complex associations contrasted with the high carriage rates in this isolated community, which might reflect the occurrence of SCCmec rearrangement and the generation of new MR-CoNS strains.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; Chromosomes, Bacterial; Coagulase; Female; French Guiana; Genes, Bacterial; Genetic Linkage; Genetic Variation; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Polymerase Chain Reaction; Prevalence; Staphylococcal Infections; Staphylococcus epidermidis; Staphylococcus haemolyticus; Staphylococcus hominis

The objectives of this study were to investigate the relationship between primary care antibiotics prescribed within 2 months and 12 months and the carriage of meticillin-resistant Staphylococcus aureus (MRSA) in nasal flora from a large representative sample of community-resident adults. S. aureus isolates were obtained from nasal samples submitted by UK resident adults aged ≥ 16 years registered with 12 general practices in the former Avon and Gloucestershire health authority areas. Individual-level antibiotic exposure data during the 12 months prior to providing the samples were collected from the primary care electronic records. MRSA status was determined by measuring resistance to cefoxitin. In total, 6937 adults were invited to take part, of whom 5917 returned a nasal sample. S. aureus was identified in 946 samples and a total of 761 participants consented to primary care record review and had complete data for the analyses. There was no evidence of an association between any antibiotic in the previous 2 months and MRSA isolation, with an adjusted odds ratio (aOR) of 1.33 [95% confidence interval (CI) 0.12-15; P=0.8]. There was a suggestion of an association between any antibiotic use in the previous 12 months and MRSA, with an aOR of 2.45 (95% CI 0.95-6.3; P=0.06). In conclusion, there is a suggestion that antibiotics prescribed within 12 months is associated with the carriage of MRSA, but not within 2 months, although the 2-month analysis had fewer data subjects and was therefore underpowered to detect this association. A larger study would be able to clarify these associations further.

Topics: Adult; Aged; Anti-Bacterial Agents; Carrier State; Cefoxitin; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Prescriptions; Primary Health Care; Staphylococcal Infections; Surveys and Questionnaires; United Kingdom

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged to be a pathogen of public health burden causing infections with significant concern. This study was conducted to investigate methicillin-resistant Staphylococcus aureus (MRSA) infection in pet dogs and cats as an emerging zoonosis that could be disseminated in the community. A total of 184 (nasal, oral, ear and wound) swabs were collected from 70 pet dogs and 48 pet cats, whereas 50 nasal and oral swabs were collected from 28 apparently healthy companion persons in intimate contact with pets and without history of hospitalization. All samples were cultured for the isolation and identification of Staphylococcus aureus using selective media, biochemical and serological tests, while isolates were identified as MRSA after antimicrobial susceptibility testing and determination of the MIC. PCR was applied using specific primers to confirm MRSA. Three MRSA isolates have been recovered from two dogs of 70 (2.9%) and one isolate from 28 examined persons (3.6%), while none of the examined cats yielded MRSA. Furthermore, we found that two MRSA isolates recovered from one diseased dog seemed to be hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA), whereas the other dog isolate as well as the human isolate were considered as community-acquired (CA-MRSA). The occurrence of MRSA in apparently healthy and/or diseased pet dogs makes it an emerging veterinary pathogen which could be considered a public health burden if it is disseminated in our community outside hospitals.

Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Egypt; Humans; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Public Health; Staphylococcal Infections; Zoonoses

The aim was to prospectively describe the colonization pattern of coagulase-negative staphylococci (CoNS) and the relationship between colonizing and invasive CoNS isolates among patients undergoing treatment for hematological malignancy. Fourteen newly diagnosed patients were included with either multiple myeloma or acute leukemia. Patients were repeatedly sampled from nares, throat, axillae, and perineum, and the CoNS isolates obtained were phenotypically characterized together with blood isolates of CoNS using the PhenePlate system (PhP). During the treatment a gradual reduction in the heterogeneity of colonizing CoNS was observed as well as an inter-patient accumulation of phenotypically related and multi-drug-resistant CoNS. These clusters of CoNS persisted for 2-3 months after the end of therapy. Ten positive blood cultures of CoNS were obtained and in the majority of these cases CoNS of the same PhP type were found in superficial cultures collected prior to the blood culture sampling. In conclusion, the study shows that therapy for hematological malignancy is associated with a homogenization of colonizing CoNS isolates and that this acquired flora of CoNS is persistent several months after the end of therapy. Furthermore, the results suggest that the source of bloodstream infections of CoNS in hematological patients is colonizing CoNS of the skin and mucosa.

Topics: Adolescent; Adult; Aged; Axilla; Bacteremia; Bacterial Typing Techniques; Carrier State; Cluster Analysis; Coagulase; Drug Resistance, Multiple, Bacterial; Hematologic Neoplasms; Humans; Middle Aged; Nose; Perineum; Pharynx; Phenotype; Prospective Studies; Staphylococcal Infections; Staphylococcus; Young Adult

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST398 isolated from pigs raised in conventional farms was previously reported. Here we report a study on 25 farms adhering to an alternative system. LA-MRSA ST398 was not detected in nasal swabs from 178 pigs or from 89 humans working and living on these farms.

Topics: Animals; Animals, Domestic; Carrier State; Livestock; Methicillin-Resistant Staphylococcus aureus; Molecular Typing; Nose; Staphylococcal Infections; Swine

Nasal swabs of 163 healthy sheep were obtained from two farms and one abattoir in Tunisia during 2010. Samples were inoculated in Baird Parker agar and ORSAB medium for Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) recovery, respectively. MRSA was detected in 5 of these 163 samples (3%) in ORSAB medium, and one isolate per sample was further studied. MRSA isolates were mecA-positive, typed as ST153-CC80-t044-agrIII, and contained blaZ, ant(6)-Ia, aph(3')-IIIa, erm(C), tet(K), and fusB genes encoding penicillin, streptomycin, kanamycin, erythromycin, tetracycline and fusidic acid resistance, respectively. These MRSA isolates showed indistinguishable or closely related PFGE-patterns and harboured the lukF/lukS gene encoding the Panton-Valentine leukocidin and the luk-ED, hla, hld, and hlg(v) genes. Methicillin-susceptible S. aureus (MSSA) were recovered in 68 of the 163 samples (41.7%) and one isolate per sample was characterized. Most of MSSA (82.4%) showed susceptibility to the tested antibiotics with exceptions: penicillin (6%, carrying blaZ gene), tetracycline (19%, carrying tet(K) gene) and fusidic acid (9%). The following toxin-genes were identified among MSSA: tst (53 isolates), luk-M (52), luk-ED, hla, hlb, hld and hlg(v) (67), hlg (1), sec (49), sel (52), and the egc-cluster-like sen-sem-sei-seo-seg (1). Ten spa-types (two of them new ones) and nine sequence types (six new ones) were detected among the 73 S. aureus isolates, and they were ascribed to agr types I and III. All MRSA and MSSA isolates were able to coagulate bovine plasma and MRSA harboured the immune-evasion-gene-cluster type E. Conclusions. Nares of healthy sheep could be a reservoir of PVL-positive community-associated-MRSA and also of TSST-positive S. aureus isolates, with potential implications in public health.

Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; Electrophoresis, Gel, Pulsed-Field; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Multilocus Sequence Typing; Nose; Prevalence; Sheep; Sheep Diseases; Sheep, Domestic; Staphylococcal Infections; Staphylococcus aureus; Tunisia; Virulence

In this study, we reported on the design of a multiplex real-time PCR assay based on SYBR Green I, incorporating dual priming adenine-thymine (AT)-rich primers for direct detection of MRSA from nasal samples. The multiplex real-time polymerase chain reaction (RT-PCR) assay reported in this study is based on SYBR Green I with incorporation of six dual priming AT-rich primers designed from the SCCmec/orf junction. A string (4-6 bp) of low-melting bases, such as adenine and thymine, was incorporated into the primers, which virtually divided a single primer in two functional regions, thus decreasing non-specific PCR products. The analytical sensitivity and specificity of the RT-PCR assay was determined with genomic DNA of reference strains (MRSA, MSSA, and MRCoNS). RT-PCR assay was performed for analysis of 72 nasal swab specimens, and the results were confirmed by use of a culture method. Furthermore, the results of RT-PCR were compared with LightCycler MRSA advance test. The multiplex RT-PCR assay reproducibly detected a minimum of 1 pg genomic DNA (31.5 copy of genome) of MRSA reference strains and clinical isolates, with a specific melting peak at 83.5 ± 1.5°C, and neither fluorescence nor a melting peak was detected in non-target isolates. The concordance rate between RT-PCR assay and culture method was 87.5% with Cohen's kappa value (κ) 0.75, which showed good agreement between the two assays. The sensitivity, specificity, positive predictive value, and negative predictive value of the assay were 93.5%, 82.9%, 80.5%, and 94.4%, respectively. In a comparative study for the detection of 72 nasal samples, the sensitivity, specificity, positive predictive value, and negative predictive value of the multiplex RT-PCR assay with respect to LightCycler MRSA advance test was 84.2%, 88.2%, 89%, and, 83.3%, respectively. The results of RT-PCR assay demonstrated high specificity (88.2%) and positive predictive value (89%) for the direct detection of MRSA from nasal samples.

Topics: Base Sequence; DNA Primers; Humans; Methicillin-Resistant Staphylococcus aureus; Molecular Sequence Data; Multiplex Polymerase Chain Reaction; Nose; Real-Time Polymerase Chain Reaction; Staphylococcal Infections

The study objective was to define the risk factors and the route of Staphylococcus aureus transmission between mother and newborn.. Women at late pregnancy were screened for nasal and vaginal S. aureus colonization. Newborns were screened for nasal, auricular, umbilical, and rectal colonization at birth and before discharge. Carrier mothers and their newborns were rescreened at 1 month. Pulse-field gel electrophoresis was used to assess strain genetic relatedness.. Of the 208 women screened, 34% were colonized with S. aureus. Overall, by 72-100 hours after birth, the cumulative incidence of S. aureus acquisition was 42.6/100 newborns of carrier mothers versus 7.4/100 newborns of noncarrier mothers (adjusted risk ratio = 5.7; 95% confidence interval [CI], 2.3-13.9). The risk to acquire a maternal strain was significantly higher than nonmaternal strain (adjusted risk ratio = 1.5; 95% CI, 1.3-1.9); Newborns to carrier mothers were also at a risk to acquire nonmaternal S. aureus strains compared with newborns to noncarrier mothers (adjusted risk ratio = 2.9; 95% CI, 1.6-5.4). The cumulative incidence of S. aureus acquisition was similar among newborns delivered by cesarean versus vaginal delivery (24.5 vs. 23.0/100 cases). At 1-month follow-up, the cumulative incidence of S. aureus acquisition reached 69.7/100 newborns of carrier mothers.Genetically identical strains were isolated in 32/40 (80%) mother-newborn pairs, among these, the source of the newborn strain was a maternal nasal strain in 29/32 (90%).. Newborns of carrier mothers are at risk to acquire S. aureus colonization. Most newborns of carrier mothers are colonized within the first month of life. Horizontal transmission from the mother is probably the major source for S. aureus carriage in newborns.

Topics: Adult; Carrier State; Cluster Analysis; Ear; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Infant, Newborn; Infectious Disease Transmission, Vertical; Molecular Epidemiology; Molecular Typing; Nose; Pregnancy; Pregnancy Complications, Infectious; Rectum; Staphylococcal Infections; Staphylococcus aureus; Umbilicus; Vagina

The nose is the anatomical site usually recommended for methicillin-resistant Staphylococcus aureus (MRSA) screening. Other sites are also recommended, but are more controversial. We showed that the sensitivities of MRSA detection from nasal swabs alone were 48% and 62% by culture or by rapid PCR test, respectively. These percentages increased to 79% and 92% with the addition of groin swabs, and to 96% and 99% with the addition of groin and throat swabs. In conclusion, neither by culture nor by rapid PCR test is nose sampling alone sufficient for MRSA detection. Additional anatomical sites should include at least the groin and throat.

Topics: Bacteriological Techniques; Carrier State; Groin; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Pharynx; Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections

Topics: Carrier State; Community-Acquired Infections; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections

Screening for nares carriage of methicillin-resistant Staphylococcus aureus (MRSA) could be used to identify patients at reduced risk for MRSA infection. However, recent studies suggest that negative results of nares surveillance testing are not reliable to predict a low risk for MRSA infection.. To derive a clinical prediction rule, logistic regression was performed to identify predictors of MRSA infection in patients with negative nares surveillance results. To validate the prediction rule and modifications of the rule, the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated in a prospective cohort of inpatients receiving empiric vancomycin.. A prediction rule that included 8 clinical risk factors and nares surveillance results was sensitive with NPV of 99.9%. In the validation cohort, 43 of 451 (10%) patients receiving empiric vancomycin had MRSA infection. In comparison with nares surveillance results (sensitivity, 72%; NPV, 96%), the prediction rule was more reliable for prediction of low risk for MRSA infection (sensitivity, 93%; NPV, 98%). A modified rule that included additional indications for empiric MRSA coverage based on practice guidelines reliably predicted MRSA infection (sensitivity, 100%) while excluding those at low risk (NPV, 100%).. Negative nares screening results in combination with absence of certain clinical risk factors or syndromes could provide a useful strategy to predict patients with low likelihood of MRSA infection.

Topics: Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Carrier State; Clinical Medicine; Cross Infection; Decision Support Techniques; Hospitals, Veterans; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prognosis; Retrospective Studies; Risk Assessment; Risk Factors; Staphylococcal Infections

A nasal carriage survey for methicillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit detected four strains of MRSA with reduced susceptibility to vancomycin. The vanA gene was found in two of these vancomycin-intermediate Staphylococcus aureus (VISA) strains. The absence of selective vancomycin pressure might have resulted in reduced expression of the resistant gene.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Carbon-Oxygen Ligases; Carrier State; Hospitals; Humans; India; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Vancomycin; Vancomycin Resistance

Staphylococcus aureus is an opportunistic pathogen in dairy ruminants where it is found in healthy carriage and can be a major cause of mastitis. A better knowledge of the host-pathogen interactions is needed to tackle this serious animal health problem. This study aimed at identifying S. aureus proteins differentially expressed by S. aureus in nasal colonization versus mastitis. Serological proteome analysis (SERPA) was used to examine protein samples prepared from culture supernatants of S. aureus strains originally isolated from gangrenous mastitis and nasal carriage (O11) or subclinical mastitis (O46) and to compare patterns of immune-reactive proteins. These staphylococcal proteins were revealed by sera obtained from ewes suffering from S. aureus mastitis and by sera obtained from healthy nulliparous ewes (i.e. no lactation and no mastitis or other symptoms) that were nasally colonized by S. aureus. Altogether 49 staphylococcal immune-reactive proteins were identified in this study. Patterns of proteins revealed by sera from infected- or healthy carrier- animals were comparable and analysis singled out one immune-reactive protein, N-acetylmuramyl-L-alanine amidase, which was recognized by each of the 6 sera from infected animals, when tested individually, and not by the sera of healthy carriers. This is the first study that compares the S. aureus seroproteome in colonization versus mastitis context in ruminants. These results open avenues for studies aiming at a better understanding of the balance between infection and commensal lifestyle in this opportunistic pathogen and at new prevention strategies.

Topics: Animals; Bacterial Proteins; Carrier State; Female; Mastitis; N-Acetylmuramoyl-L-alanine Amidase; Nose; Proteome; Sheep; Sheep Diseases; Sheep, Domestic; Staphylococcal Infections; Staphylococcus aureus

To measure Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization prevalence in household contacts of children with current community associated (CA)-MRSA infections (study group) in comparison with a group of household contacts of children without suspected Staphylococcus aureus infection (a control group).. This is a cross sectional study. Cultures of the anterior nares were taken. Relatedness of isolated strains was tested using pulse field gel electrophoresis (PFGE).. The prevalence of MRSA colonization in the study group was significantly higher than in the control group (18/77 (23%) vs 3/77 (3.9%); p ≤ 0.001). The prevalence of SA colonization was 28/77 (36%) in the study group and 16/77 (21%) in the control group (p = 0.032). The prevalence of SA nasal colonization among patients was 6/24 (25%); one with methicillin-susceptible S. aureus (MSSA) and 5 with MRSA. In the study (patient) group, 14/24 (58%) families had at least one household member who was colonized with MRSA compared to 2/29 (6.9%) in the control group (p = 0.001). Of 69 total isolates tested by PFGE, 40 (58%) were related to USA300. Panton-Valetine leukocidin (PVL) genes were detected in 30/52 (58%) tested isolates. Among the families with ≥1 contact colonized with MRSA, similar PFGE profiles were found between the index patient and a contact in 10/14 families.. Prevalence of asymptomatic nasal carriage of MRSA is higher among household contacts of patients with CA-MRSA disease than control group. Decolonizing such carriers may help prevent recurrent CA-MRSA infections.

Topics: Adolescent; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Cross-Sectional Studies; Electrophoresis, Gel, Pulsed-Field; Family Characteristics; Family Health; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Typing; Nose; Prevalence; Staphylococcal Infections; Young Adult

We examined the epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) nasal colonization among 3 groups of human immunodeficiency virus (HIV)-infected and 1 group of HIV-negative outpatients.. We determined prevalence and risk factors associated with MRSA colonization among women, recently incarcerated, and Hispanic HIV-infected patients and HIV-negative patients; isolates were typed by pulsed-field gel electrophoresis. Relative prevalence was calculated using Poisson regression, and logistic regression was used for multivariate analysis.. Of 601 patients, 9.3% were colonized with MRSA; 11% of HIV-infected and 4.2% of HIV-negative patients were colonized (relative prevalence, 2.6; 95% confidence interval [CI], 1.12-6.07; P = .03). Among HIV-infected patients, recently incarcerated patients had the highest colonization prevalence (15.6%) followed by women (12%); Hispanic patients had the lowest (2.8%). Eighty percent of confirmed MRSA isolates were identified as USA300. On multivariate analysis, history of incarceration or residence in alternative housing (odds ratio [OR], 2.3; 95% CI, 1.1-4.7; P = .03) was associated with MRSA colonization; Hispanic ethnicity was negatively associated (OR, 0.3; 95% CI, .11-.98; P = .045). There was a trend (OR, 1.6; 95% CI, .9-3.0; P = .097) toward geographic location of residence being associated with colonization. After controlling for incarceration, residence, and geography, HIV status was no longer significantly associated with colonization.. The CA-MRSA and HIV epidemics have intersected. Examination of networks of individuals released from incarceration, both HIV positive and negative, is needed to assess the role of social networks in spread of CA-MRSA and inform prevention strategies.

Topics: Adult; Aged; Community-Acquired Infections; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; HIV; HIV Infections; Humans; Illinois; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Phenotype; Prevalence; Regression Analysis; Risk Factors; Staphylococcal Infections

Inflammatory bowel disease (IBD) patients may be at increased risk of acquiring antibiotic-resistant organisms (ARO). We sought to determine the prevalence of colonization of methicillin-resistant Staphylococcus aureus (MRSA), Enterobacteriaceae containing extended spectrum beta-lactamases (ESBL), and vancomycin-resistant enterococi (VRE) among ambulatory IBD patients.. We recruited consecutive IBD patients from clinics (n=306) and 3 groups of non-IBD controls from our colon cancer screening program (n=67), the family medicine clinic (n=190); and the emergency department (n=428) from the same medical center in Toronto. We obtained nasal and rectal swabs for MRSA, ESBL, and VRE and ascertained risk factors for colonization.. Compared to non-IBD controls, IBD patients had similar prevalence of colonization with MRSA (1.5% vs. 1.6%), VRE (0% vs. 0%), and ESBL (9.0 vs. 11.1%). Antibiotic use in the prior 3 months was a risk factor for MRSA (OR, 3.07; 95% CI: 1.10-8.54), particularly metronidazole. Moreover, gastric acid suppression was associated with increased risk of MRSA colonization (adjusted OR, 7.12; 95% CI: 1.07-47.4). Predictive risk factors for ESBL included hospitalization in the past 12 months (OR, 2.04, 95% CI: 1.05-3.95); treatment with antibiotics it the past 3 months (OR, 2.66; 95% CI: 1.37-5.18), particularly prior treatment with vancomycin or cephalosporins.. Ambulatory IBD patients have similar prevalence of MRSA, ESBL and VRE compared to non-IBD controls. This finding suggests that the increased MRSA and VRE prevalence observed in hospitalized IBD patients is acquired in-hospital rather than in the outpatient setting.

Topics: Adult; Aged; Ambulatory Care; Anti-Bacterial Agents; beta-Lactamases; Carrier State; Cephalosporins; Enterobacteriaceae; Enterobacteriaceae Infections; Enterococcus; Female; Histamine H2 Antagonists; Hospitalization; Humans; Inflammatory Bowel Diseases; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Metronidazole; Middle Aged; Nose; Prevalence; Proton Pump Inhibitors; Rectum; Risk Factors; Staphylococcal Infections; Vancomycin; Vancomycin Resistance; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) ST398 has recently been described as a zoonotic agent. Its transmission between animals seems to be a pivotal factor in its emergence and dissemination. This experimental trial was performed to describe MRSA ST398 contamination and transmission in pigs after a low dose inoculation.. Twelve specific pathogen-free (SPF) pigs were randomly divided between two separate pens. Three pigs in each pen received a nasal inoculation of 2 × 10(4) colony-forming units per animal, and three naïve pigs were left in contact with them. Every 2 days and at necropsy, different samples were screened for MRSA. It was detected in nasal swabs from five inoculated and three naïve contact pigs, as early as 1 day after inoculation. MRSA was also found in environmental wipes but never in faecal samples. At necropsy, MRSA was detected in the lymph nodes of two contact pigs and in the tonsils and lymph nodes of three inoculated pigs. Twelve other SPF pigs were included as negative control in a separate room.. This experiment showed that inoculation of a low dose of MRSA ST398 could lead to the horizontal transmission of the bacterium between pigs, the contamination of mandibular lymph nodes and the contamination of the environment without faecal carriage.. The minimal inoculated dose via nasal route to observe transmission of MRSA ST398 between pigs is equal or lower to 2 × 10(4) colony-forming units per animal, and faecal excretion seems not to be a necessary condition for horizontal transmission.

Topics: Animals; Feces; Humans; Lymph Nodes; Methicillin-Resistant Staphylococcus aureus; Nose; Specific Pathogen-Free Organisms; Staphylococcal Infections; Swine; Swine Diseases

To investigate the prevalence and molecular epidemiology of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) nasal carriage in children.. We collected nasal and nasopharyngeal swabs from 2211 children aged 2-5 years attending 79 day care centers (DCCs) and 113 kindergartens (KGs) in all 18 geographical districts in Hong Kong.. The overall carriage rates of S. aureus and MRSA were 27.6% (95% confidence interval [CI], 24.8-28.5%) and 1.3% (95% CI, 0.8-1.8%), respectively. Molecular typing (staphylococcal cassette chromosome mec [SCCmec], sequence type [ST], clonal cluster [CC]) showed that all the 28 MRSA isolates had SCCmec IV (n = 13) or V (n = 15) including 12 isolates with community-associated-MRSA genotypes (ST59-IV/V, ST30-IV and ST88-V), 10 isolates with healthcare-associated-MRSA genotypes (ST45-IV/V, CC5-IV and ST630-V) and six isolates with novel genotypes (ST10-V and CC1-IV). Spa typing indicated that there was some within and between DCCs/KGs transmission of certain MRSA and methicillin-sensitive S. aureus strains but this was not extensive.. Our findings indicate the potential for DCCs to be a reservoir for emerging MRSA genotypes and highlight the need to enhance education and infection control measures to reduce their cross-transmission in this population.

Topics: Carrier State; Child Day Care Centers; Child, Preschool; Female; Hong Kong; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Molecular Typing; Nasopharynx; Nose; Prevalence; Staphylococcal Infections

The anterior naris has been considered the most consistent location of asymptomatic Staphylococcus aureus colonization. However, recent studies have shown that a substantial number of individuals, ranging from 7% to 32% of colonized individuals, are exclusive throat carriers. Most of these studies have been carried out in a health care setting, limiting their generalizability to nonhospitalized populations.. To evaluate anatomic carriage sites of S aureus in individuals outside of a health care setting, we combined the results of 2 cross-sectional studies conducted in Iowa.. S aureus was carried by 103 of 340 individuals (30.3%), including 31 (30.1%) exclusive throat carriers, 44 (42.7%) exclusive nose carriers, and 28 (27.2%) colonized in both sites. Nonwhite race (adjusted odds ratio [OR], 4.91; 95% confidence interval [CI], 1.26-18.3) and younger age (≥30 years: OR, 0.23; 95% CI, 0.10-0.54) were associated with increased odds of exclusive throat carriage, whereas nonwhite race (OR, 5.14; 95% CI, 1.62-16.3) and spring or summer sampling season (OR, 2.62; 95% CI, 1.32-5.18) were associated with increased odds of exclusive nasal carriage.. These findings suggest that including a throat swab in addition to a nasal swab could play an important role in the success of surveillance programs, particularly among younger adults.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Cross-Sectional Studies; Female; Humans; Iowa; Male; Middle Aged; Nose; Pharynx; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Staphylococcus epidermidis is a harmless commensal, but it can become a human pathogen, mainly in the hospital environment. In order to clarify strategies used by these bacteria to adapt to the hospital environment, we compared the population structure and staphylococcal cassette chromosome mec (SCCmec) content of S. epidermidis from the community and hospital.. S. epidermidis were collected from nasal swabs of both healthy military draftees (192 isolates) and patients (94 isolates) recovered in the same time period and geographical region. S. epidermidis were characterized by PFGE, multilocus sequence typing and SCCmec typing.. Clonal complex 5 was predominant in the hospital (100%) and the community (58%), but some clonal types were specific to each environment and others were found in both (C/H clones). The methicillin-resistant S. epidermidis (MRSE) colonization rate in the community was very low (7%) when compared with the hospital (30%; P < 0.05). Community-associated MRSE carried mostly SCCmec IV and V [Simpson's index of diversity (SID) = 57.52%; 95% CI 38.35-76.69], whereas hospital-associated MRSE carried 17 SCCmec structures (SID = 82.67%; 95% CI 77.38-87.96). Isolates of the same PFGE type had a much higher number of different SCCmec types when collected in the hospital than in the community.. Our data suggest that the S. epidermidis population is composed of hospital-associated clonal types, community-associated clonal types and types that are able to survive in both environments. Moreover, adaptation to the hospital environment in S. epidermidis appears to promote an increase in the frequency and diversification of SCCmec.

Topics: Adaptation, Biological; Biota; Carrier State; Chromosomes, Bacterial; Cluster Analysis; Community-Acquired Infections; Cross Infection; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genetic Variation; Humans; Military Personnel; Multilocus Sequence Typing; Nose; Staphylococcal Infections; Staphylococcus epidermidis

The risk of acquisition of antibiotic resistant-bacteria during or shortly after antibiotic therapy is still unclear and it is often confounded by scarce data on antibiotic usage.Primary objective of the study is to compare rates of acquisition of methicillin-resistant Staphylococcus aureus and extended spectrum beta-lactamase-producing Enterobacteriaceae in hospitalised patients, after starting antibiotic therapy.. The study, running in three European hospitals, is a multicenter, prospective, longitudinal, observational cohort study funded from the European Community's Seventh Framework Programme [FP7/2007-2013] within the project 'Impact of Specific Antibiotic Therapies on the prevalence of hUman host ResistaNt bacteria' (acronym SATURN). Nasal and rectal screening for methicillin-resistant Staphylococcus aureus and extended spectrum beta-lactamase-producing Enterobacteriaceae will be obtained at hospital admission, discharge, at antibiotic start (t0, within one hour) and at the following intervals: day 3 (t1), 7 (t2), 15 (t3), and 30 (t4). Two nested case-control studies will be performed. The objective of the first study will be to define individual level of risk related to specific antibiotics. Patients acquiring methicillin-resistant Staphylococcus aureus and extended spectrum beta-lactamase-producing Enterobacteriaceae (cases) will be compared with patients not acquiring antibiotic-resistant strains after starting antibiotic therapy (controls; ratio 1:4). To define the impact of antibiotics on new acquisition of target antibiotic-resistant bacteria, a second nested case-control study will be done (ratio 1:4). Control group will be selected among patients not receiving antibiotics, admitted in the same ward on the day of the corresponding case, with negative cultures at admission. Epidemiological, clinical and microbiological data will be prospective collected.. The rationale of this study is to better understand the impact of antibiotic use on acquisition, selection and transmission of antimicrobial resistant-bacteria in European hospitals.. ClinicalTrials.gov NCT01208519.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Case-Control Studies; Child; Child, Preschool; Cross Infection; Drug Utilization; Enterobacteriaceae; Enterobacteriaceae Infections; Europe; Feces; Female; Hospitals; Humans; Infant; Infant, Newborn; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Prospective Studies; Staphylococcal Infections; Young Adult

The Cepheid Xpert MRSA/SA nasal PCR assay was compared to culture for quantifying Staphylococcus aureus load from 104 nasal samples (r = 0.91, P < 0.0001). Using a bacterial load-based algorithm, the test was found able to predict the carrier state in 32 of 35 healthy volunteers (22 persistent and 13 nonpersistent carriers).

Topics: Algorithms; Bacterial Load; Carrier State; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections

Since the relationship between dogs and their owners has changed, and dogs moved from being working dogs to family members in post-industrial countries, we hypothesized that zoonotic transmission of opportunistic pathogens like coagulase positive staphylococci (CPS) is likely between dogs and their owners.. CPS- nasal carriage, different aspects of human-to-dog relationship as well as potential interspecies transmission risk factors were investigated by offering nasal swabs and a questionnaire to dog owners (108) and their dogs (108) at a dog show in 2009. S. aureus was found in swabs of 20 (18.5%) humans and two dogs (1.8%), and spa types which correspond to well known human S. aureus lineages dominated (e.g. CC45, CC30 and CC22). Multilocus sequence typing (MLST) of the two canine strains revealed ST72 and ST2065 (single locus variant of ST34). Fifteen dogs (13.9%) and six owners (5.6%) harboured S. pseudintermedius, including one mecA-positive human isolate (MRSP). Pulsed field gel electrophoresis (PFGE) revealed that one dog/owner pair harboured indistinguishable S. pseudintermedius- isolates of ST33. Ten (48%) of the 21 S. pseudintermedius-isolates showed resistance towards more than one antimicrobial class. 88.9% of the dog owners reported to allow at least one dog into the house, 68.5% allow the dog(s) to rest on the sofa, 39.8% allow their dogs to come onto the bed, 93.5% let them lick their hands and 52.8% let them lick their face. Bivariate analysis of putative risk factors revealed that dog owners who keep more than two dogs have a significantly higher chance of being colonized with S. pseudintermedius than those who keep 1-2 dogs (p<0.05).. In conclusion, CPS transmission between dog owners and their dogs is possible. Further investigation regarding interspecies transmission and the diverse adaptive pathways influencing the epidemiology of CPS (including MRSA and MRSP) in different hosts is needed.

Topics: Adult; Aged; Aged, 80 and over; Animals; Bacterial Typing Techniques; Coagulase; Dogs; Female; Humans; Male; Middle Aged; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus; Young Adult

Recent studies have shown that livestock can carry Staphylococcus aureus and transmit it to human caretakers. We conducted a pilot study to determine the prevalence and molecular epidemiology of S. aureus among rural Iowans, including individuals with livestock contact. Nasal and throat swabs were collected and plated onto selective media to isolate methicillin-susceptible and methicillin-resistant S. aureus (MRSA), followed by antibiotic resistance testing and molecular analysis of the isolates. While no MRSA was detected, overall, 23.7% (31/131) of participants were found to harbor S. aureus in their nose, throat, or both. Fifteen isolates displayed resistance to one or more tested antibiotics, and the Panton-Valentine leukocidin (PVL) genes were present at a high level (29% [9/31] of S. aureus-positive participants). Younger age and tobacco use were associated with increased risk of S. aureus carriage. Our results suggest that carriage of PVL-positive S. aureus is common among rural Iowans, even in the absence of detectable MRSA colonization.

Topics: Adult; Animals; Anti-Bacterial Agents; Bacterial Toxins; Carrier State; Exotoxins; Female; Humans; Iowa; Leukocidins; Livestock; Male; Methicillin; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Pharynx; Phylogeny; Prevalence; Risk Factors; Rural Population; Staphylococcal Infections; Staphylococcus aureus

To assess livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage among workers in pig slaughterhouses and assess associated risk factors, including occupational exposure to LA-MRSA.. A cross-sectional study in three Dutch pig slaughterhouses was undertaken. Nasal swabs of participants were taken. Nasal swabs and surface wipes, air and glove samples were screened for presence of methicillin-resistant Staphylococcus aureus (MRSA). MRSA was quantitatively determined on gloves and in air samples by culturing and real-time PCR.. 11 of 341 (3.2%) participants were identified as nasal MRSA carriers. MRSA-positive workers were predominantly found at the start of the slaughter process. Major risk factors for carriage were working in the lairage and working in the scalding and dehairing area. Most nasal isolates (73%) belonged to the LA-MRSA clone ST398. MRSA ST398-positive environmental samples were found throughout the slaughter process. A clear decrease was seen along the slaughterline in the number of MRSA-positive samples and in the MRSA amount per sample.. This study showed that working in the lairage area or scalding and dehairing area were the major risk factors for MRSA carriage in pig slaughterhouse workers, while the overall prevalence of MRSA carriage is low. Occupational exposure to MRSA decreased along the slaughterline, and the risk of carriage showed a parallel decrease.

Topics: Abattoirs; Adult; Aged; Animals; Carrier State; Cell Culture Techniques; Cross-Sectional Studies; Humans; Livestock; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Netherlands; Nose; Occupational Exposure; Occupations; Real-Time Polymerase Chain Reaction; Risk Factors; Staphylococcal Infections; Swine; Young Adult

To identify risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) acquisition in long-term care facility (LTCF) residents.. Multicenter, prospective cohort followed over 6 months.. Three Veterans Affairs (VA) LTCFs.. All current and new residents except those with short stay (<2 weeks).. MRSA carriage was assessed by serial nares cultures and classified into 3 groups: persistent (all cultures positive), intermittent (at least 1 but not all cultures positive), and noncarrier (no cultures positive). MRSA acquisition was defined by an initial negative culture followed by more than 2 positive cultures with no subsequent negative cultures. Epidemiologic data were collected to identify risk factors, and MRSA isolates were typed by pulsed-field gel electrophoresis (PFGE).. Among 412 residents at 3 LTCFs, overall MRSA prevalence was 58%, with similar distributions of carriage at all 3 facilities: 20% persistent, 39% intermittent, 41% noncarriers. Of 254 residents with an initial negative swab, 25 (10%) acquired MRSA over the 6 months; rates were similar at all 3 LTCFs, with no clusters evident. Multivariable analysis demonstrated that receipt of systemic antimicrobials during the study was the only significant risk factor for MRSA acquisition (odds ratio, 7.8 [95% confidence interval, 2.1-28.6]; P = .002). MRSA strains from acquisitions were related by PFGE to those from a roommate in 9/25 (36%) cases; 6 of these 9 roommate sources were persistent carriers.. MRSA colonization prevalence was high at 3 separate VA LTCFs. MRSA acquisition was strongly associated with antimicrobial exposure. Roommate sources were often persistent carriers, but transmission from roommates accounted for only approximately one-third of MRSA acquisitions.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Cross Infection; Female; Hospitals, Veterans; Humans; Infection Control; Logistic Models; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Multivariate Analysis; Nose; Prevalence; Prospective Studies; Residential Facilities; Risk Factors; Staphylococcal Infections

To investigate the presence and the genetic environment of the multiresistance gene cfr in Jeotgalicoccus pinnipedialis and Macrococcus caseolyticus from pigs.. A total of 391 bacterial isolates with florfenicol MICs ≥16 mg/L were obtained from nasal swabs of 557 individual pigs; of these, 75 Gram-positive isolates other than staphylococci and enterococci were screened by PCR for the presence of known florfenicol resistance genes. Species assignments of the cfr-carrying isolates were based on the results of biochemical profiling and 16S rDNA sequencing. The locations of the cfr gene were determined by Southern blotting. Regions flanking each cfr gene were sequenced by a modified random primer walking strategy, and the transferability of cfr was assessed by electrotransformation.. Two M. caseolyticus isolates and one J. pinnipedialis isolate were cfr positive. The cfr gene was located either on a 7057 bp plasmid, pSS-03, which was widely distributed among staphylococci of pig origin, or on the ∼53 kb plasmid pJP1. The region of pJP1 that included the cfr gene and the adjacent IS21-558, showed 99.7% identity to the corresponding region of plasmid pSCFS3. In addition, the genes aadD + aacA-aphD, ble and erm(C), coding for aminoglycoside, bleomycin and macrolide-lincosamide-streptogramin B resistance, respectively, were also identified on plasmid pJP1.. This study showed that plasmids carrying the multidrug resistance gene cfr are present in two new genera of commensal and environmental bacteria, Macrococcus and Jeotgalicoccus. This observation underlines the role of commensal and environmental flora in the dissemination of clinically important resistance genes, such as cfr.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Blotting, Southern; Carrier State; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Nose; Plasmids; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Staphylococcaceae; Staphylococcal Infections; Swine; Thiamphenicol

Rapid detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) followed by appropriate infection control procedures reduces MRSA infection and transmission. We compared the performance and workflow of two Food and Drug Administration-approved nucleic acid amplification assays, the LightCycler MRSA Advanced Test and the Xpert MRSA test, with those of directly plated culture (MRSASelect) using 1202 nasal swabs collected at three U.S. sites. The sensitivity of the LightCycler test (95.2%; 95% CI, 89.1% to 98.4%) and Xpert assay (99%; 95% CI, 94.8% to 100%) did not differ compared with that of culture; the specificity of the two assays was identical (95.5%; 95% CI, 94.1% to 96.7%) compared with culture. However, sequencing performed on 71 samples with discordant results among the three methods confirmed the presence of MRSA in 40% of samples that were positive by both molecular methods but negative by culture. Workflow analysis from all sites including batch runs revealed average hands-on sample preparation times of 1.40, 2.35, and 1.44 minutes per sample for the LightCycler, Xpert, and MRSASelect methods, respectively. Discrete event simulation analysis of workflow efficiencies revealed that the LightCycler test used less hands-on time for the assay when greater than eight batched samples were run. The high sensitivity and specificity, low hands-on time, and efficiency gains using batching capabilities make the LightCycler test suitable for rapid batch screening of MRSA colonization.

Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Workflow

This study was undertaken to determine the rate of methicillin-resistant Staphylococcus aureus (MRSA) colonization predicted by clinical risk factors compared with determination by nasal swab culture and polymerase chain reaction in emergency department patients.. From November 2009 to March 2011, patients seen in the emergency department were studied prospectively. The risk of MRSA colonization was determined by clinical risk factors, and both surveillance cultures and a polymerase chain reaction assay were performed in each patient.. A total of 277 patients was enrolled, and 31.4% (87/277) of patients had a positive surveillance culture or a MRSA polymerase chain reaction assay. The rate of colonization in patients with high-risk factors included the following: past history of colonization/infections, 60.0%; history of previous antibiotic use, 47.2%; more than 30 days hospitalization in the past 3 months, 43.9%; more than 10 days hospitalization in the past 3 months, 41.7%; and a history of hospitalization because of acute illness, 40.0%.. The prevalence rate of colonization in patients with a high risk of MRSA colonization exceeded 30%. Active surveillance cultures should be considered in patients at high risk for MRSA colonization.

Topics: Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Carrier State; Decision Support Techniques; Emergency Service, Hospital; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Young Adult

In 30% of carriers, Staphylococcus aureus colonization affects exclusively the pharynx and occurs independently from its presence in the nares. This additional reservoir has implications for S. aureus transmission, infection, and decolonization. Host factors promoting colonization of the throat, however, are unknown.. We determined pharyngeal and persistent nasal carriage of S. aureus, ABO histo-blood group and ABH secretor status phenotypes in 227 individuals.. Compared to group A/non-secretors, group O/non-secretor individuals were at increased risk of carrying S. aureus in their throat (OR 6.50, 95% confidence interval 1.28-33.03, P = 0.02) and group O/secretor individuals were protected (OR 0.24, 0.07-0.77, P = 0.02). Both associations became moderately stronger after adjusting for persistent S. aureus nasal carriage, which was found to be a risk factor for pharyngeal colonization in the univariable analysis (OR 2.41, 1.35-4.33, p = 0.003). Most simultaneous carriers (72%) had identical S. aureus genotypes in their nose and throat.. These findings are consistent with in vitro studies that proposed a role of histo-blood group antigens as ligands for S. aureus and support their contribution to the observed population variation in nasopharyngeal S. aureus colonization. Based on their tissue specific expression histo-blood group antigens appear to modulate individual S. aureus colonization patterns.

Topics: ABO Blood-Group System; Adult; Carrier State; Female; Human Experimentation; Humans; Male; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To determine the proportion of methicillin-resistant Staphylococcus aureus (MRSA) detections identified by nasal swabbing using agar culture in comparison with multiple body site testing using agar and nutrient broth culture.. Cross-sectional study.. Adult patients admitted to 36 general specialty wards of 2 large hospitals in Scotland.. Patients were screened for MRSA via multiple body site swabs (nasal, throat, axillary, perineal, and wound/invasive device sites) cultured individually on chromogenic agar and pooled in nutrient broth. Combined results from all sites and cultures provided a gold-standard estimate of true MRSA prevalence.. This study found that nasal screening performed better than throat, axillary, or perineal screening but at best identified only 66% of true MRSA carriers against the gold standard at an overall prevalence of 2.9%. Axillary screening performed least well. Combining nasal and perineal swabs gave the best 2-site combination (82%). When combined with realistic screening compliance rates of 80%-90%, nasal swabbing alone probably detects just over half of true colonization in practice. Swabbing of clinically relevant sites (wounds, indwelling devices, etc) is important for a small but high-prevalence group.. Nasal swabbing is the standard method in many locations for MRSA screening. Its diagnostic efficiency in practice appears to be limited, however, and the resource implications of multiple body site screening have to be balanced against a potential clinical benefit whose magnitude and nature remains unclear.

Topics: Aged; Aged, 80 and over; Axilla; Bacteriological Techniques; Carrier State; Cross Infection; Cross-Sectional Studies; Culture Media; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Perineum; Pharynx; Staphylococcal Infections; Wounds, Penetrating

This is the first large-scale study of Staphylococcus pseudintermedius colonization and diversity in healthy dogs where samples were collected over a long time and strains were identified by PCR according to the current taxonomy of the S. intermedius group and typed by a highly discriminatory method such as pulsed field gel electrophoresis (PFGE). A cross-sectional study of nasal, oral, perineal and inguinal carriage in 119 healthy dogs was followed by a longitudinal study where oral and perineal carriage was examined in 16 dogs for 10 times over a period of 1 year. Altogether we collected 762 samples and 285 S. pseudintermedius isolates, 182 of which were typed by PFGE to determine spatial and temporal strain diversity within individual carriers. In the cross-sectional study, S. pseudintermedius was isolated from at least one body site in 82 (69%) of the 119 dogs. The most frequent carriage sites were the perineum (66%) and the mouth (65%) followed by the nose (27%) and the groin (23%). PFGE analysis showed high heterogeneity among the isolates originating from different body sites of the same dog. Fifteen of the 16 dogs sampled longitudinally carried S. pseudintermedius in at least one sampling time, including six dogs that were negative in the cross-sectional study. Our results indicate that S. pseudintermedius carriage in dogs is more frequent and heterogeneous than S. aureus carriage in humans. This observation might reflect the hygienic standards and social behavior of the canine host, which facilitates transmission of this bacterium in the dog population.

Topics: Animals; Cluster Analysis; Cross-Sectional Studies; Denmark; Dog Diseases; Dogs; Electrophoresis, Gel, Pulsed-Field; Genetic Variation; Longitudinal Studies; Nose; Staphylococcal Infections; Staphylococcus

Topics: Animals; Carrier State; China; Disease Reservoirs; Female; Male; Meat; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Swine; Swine Diseases; Zoonoses

Animals on farms may be a potential reservoir and environmental source of methicillin-resistant Staphylococcus aureus (MRSA). Expanded surveillance methods for animal-associated MRSA are needed. To develop an environmental sampling method and to determine the correlation between animal and environmental MRSA positivity in the farm setting, we sampled horses, cattle, and their local environments at several farms in the mid-Atlantic United States. We obtained nasal swabs from 13 racehorses at first visit, and 11 racehorses at the same farm eight weeks later. We also sampled 26 pleasure horses and 26 beef cattle from two additional farm sites. Sterilized electrostatic cloths were used to collect dry dust samples from environmental surfaces in proximity to animals; cloths were cultured using a broth enrichment protocol. We described isolates by genotype and antimicrobial susceptibility phenotype. None of the samples (nasal or environmental) were positive from the pleasure horse farm or the cattle farm. On the racehorse farm, 8/13 (61%) nasal and 5/7 (71%) environmental samples were positive for MRSA at the first visit. Isolates found were indistinguishable by pulsed-field gel electrophoresis (PFGE) genotype. We observed significant positive correlation between nasal carriage of MRSA in animals and our ability to isolate MRSA from dry surface samples of their local environments. The methods presented here may aid in surveillance efforts for equine and other animal MRSA. This study successfully applies existing MRSA surveillance methods for indoor, high animal density settings to outdoor and low-density farms.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Electrophoresis, Gel, Pulsed-Field; Environmental Microbiology; Genes, Bacterial; Genotype; Horse Diseases; Horses; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; United States

The right and left nares of healthy adults (n = 251) were swabbed separately to determine carriage of Staphylococcus aureus in each nostril. Carriers were significantly more likely to carry S. aureus in one nostril than in both. Of those carrying S. aureus in both nostrils, 20% carried genetically distinct strains in each. Nostrils belonging to a single individual should not be assumed to be homogenous with respect to carriage of S. aureus.

Topics: Adolescent; Adult; Aged; Carrier State; Electrophoresis, Gel, Pulsed-Field; Female; Healthy Volunteers; Humans; Male; Middle Aged; Molecular Typing; Nose; Staphylococcal Infections; Staphylococcus aureus; Young Adult

The objective was to evaluate the performance of surveillance cultures at various body sites for Staphylococcus aureus colonization in pregnant women and newborns (NB) and the factors associated with nasal colonization. For NB, 4 sites were evaluated: nares, oropharynx, perineum, and umbilical stump (birth, third day, and weekly). For pregnant women, 4 sites during labor: anterior nares, anus, perineum, and oropharynx. Nasally colonized patients were compared with colonized only extranasally. Colonization was 53% of 392 pregnant women (methicillin-resistant S. aureus [MRSA]: 4%) and 47% of 382 NB (MRSA: 9%). For newborn patients, the best body site was the umbilical stump (methicillin-susceptible S. aureus [MSSA]: 64%; MRSA: 68%) and the combination of nares + umbilical (MSSA: 86%; MRSA: 91%). Among pregnant women, the best body site was the anterior nares (MSSA: 59%; MRSA: 67%) and the combination of nares + oropharynx (MSSA: 83%; MRSA: 80%). A smaller number of household members were associated with MRSA carriage in pregnant women (2.2 ± 0.6 versus 3.6 ± 1.8; P = 0.04). In conclusion, multiple culture sites are needed. Control programs based on surveillance cultures may be compromised.

Topics: Adolescent; Adult; Bacteriological Techniques; Carrier State; Epidemiologic Methods; Female; Humans; Infant, Newborn; Male; Middle Aged; Nasopharynx; Nose; Perineum; Pregnancy; Pregnancy Complications, Infectious; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Umbilicus; Young Adult

In the absence of established methicillin-resistant Staphylococcus aureus (MRSA) screening programs, many centers use a history of a positive culture or a nasal screen as a surrogate for preoperative MRSA colonization status. We aimed to evaluate the test characteristics of these surrogates.. Retrospective cohort study.. Veterans Affairs Boston Healthcare System surgical patients with a preoperative nasal MRSA polymerase chain reaction (PCR) screen.. We assessed the performance of a history of a MRSA-positive culture or a positive nasal MRSA PCR screen during the year prior to surgery for predicting the preoperative nasal PCR screen result. The associations between MRSA history and postoperative outcomes, including MRSA cultures and infections, were also evaluated.. Among 4,238 patients, a positive MRSA culture history had a sensitivity of 19.7% (95% confidence interval [CI], 15.4%-24.8%) and positive predictive value of 57.3% for the preoperative nasal MRSA status. The specificity of MRSA culture history was 99% (95% CI, 98.5%-99.2%). Prior-year nasal MRSA screen results had similar test characteristics. A history of a MRSA-positive culture was associated with an increased risk of postoperative MRSA-positive cultures (risk ratio [RR], 3.54 [95% CI, 1.70-7.37], [Formula: see text]) but not of infections (RR, 1.71 [95% CI, 0.58-5.01]), after adjustment for preoperative nasal MRSA status, vancomycin surgical prophylaxis, surgical scrub, and age.. A history of a MRSA-positive culture and a positive nasal PCR screen are poor surrogate markers of preoperative colonization status, missing at least 70% of MRSA-colonized patients. Prior-year history is also not independently associated with MRSA-related postoperative infections. Strong consideration should be given to preoperative MRSA screening in patients at high risk for surgical complications.

Topics: Boston; Female; Hospitals, Veterans; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Postoperative Complications; Predictive Value of Tests; Preoperative Period; Retrospective Studies; Sensitivity and Specificity; Staphylococcal Infections

MRSA prevalence in nursing homes often exceeds that in hospitals, but reasons for this are not well understood. We sought to measure MRSA burden in a large number of nursing homes and identify facility characteristics associated with high MRSA burden.. We performed nasal swabs of residents from 26 nursing homes to measure MRSA importation and point prevalence, and estimate transmission. Using nursing home administrative data, we identified facility characteristics associated with MRSA point prevalence and estimated transmission risk in multivariate models.. We obtained 1,649 admission and 2,111 point prevalence swabs. Mean MRSA point prevalence was 24%, significantly higher than mean MRSA admission prevalence, 16%, (paired t-test, p<0.001), with a mean estimated MRSA transmission risk of 16%.In multivariate models, higher MRSA point prevalence was associated with higher admission prevalence (p=0.005) and higher proportions of residents with indwelling devices (p=0.01). Higher estimated MRSA transmission risk was associated with higher proportions of residents with diabetes (p=0.01) and lower levels of social engagement (p=0.03).. MRSA importation was a strong predictor of MRSA prevalence, but MRSA burden and transmission were also associated with nursing homes caring for more residents with chronic illnesses or indwelling devices. Frequent social interaction among residents appeared to be protective of MRSA transmission, suggesting that residents healthy enough to engage in group activities do not incur substantial risks of MRSA from social contact. Identifying characteristics of nursing homes at risk for high MRSA burden and transmission may allow facilities to tailor infection control policies and interventions to mitigate MRSA spread.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Child; Child, Preschool; Cross Infection; Female; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Nursing Homes; Risk Factors; Staphylococcal Infections; Young Adult

The objective of this study was to determine the genetic lineages and the incidence of antibiotic resistance and virulence determinants of nasal Staphylococcus aureus isolates of healthy donkeys destined to food consumption in Tunisia.. Nasal swabs of 100 donkeys obtained in a large slaughterhouse in 2010 were inoculated in specific media for S. aureus and methicillin-resistant S. aureus (MRSA) recovery. S. aureus was obtained in 50% of the samples, being all of isolates methicillin-susceptible (MSSA). Genetic lineages, toxin gene profile, and antibiotic resistance mechanisms were determined in recovered isolates. Twenty-five different spa-types were detected among the 50 MSSA with 9 novel spa-types. S. aureus isolates were ascribed to agr type I (37 isolates), III (7), II (4), and IV (2). Sixteen different sequence-types (STs) were revealed by MLST, with seven new ones. STs belonging to clonal clomplex CC133 were majority. The gene tst was detected in 6 isolates and the gene etb in one isolate. Different combinations of enterotoxin, leukocidin and haemolysin genes were identified among S. aureus isolates. The egc-cluster-like and an incomplete egc-cluster-like were detected. Isolates resistant to penicillin, erythromycin, fusidic acid, streptomycin, ciprofloxacin, clindamycin, tetracycline, or chloramphenicol were found and the genes blaZ, erm(A), erm(C), tet(M), fusC were identified.. The nares of donkeys frequently harbor MSSA. They could be reservoirs of the ruminant-associated CC133 lineage and of toxin genes encoding TSST-1 and other virulence traits with potential implications in public health. CC133 seems to have a broader host distribution than expected.

Topics: Abattoirs; Animals; Anti-Bacterial Agents; Disease Reservoirs; Drug Resistance, Bacterial; Equidae; Genetic Variation; Nose; Staphylococcal Infections; Staphylococcus aureus; Tunisia; Virulence

Staphylococcus aureus, particularly methicillin resistant (MRSA), is a common pathogen among patients receiving hemodialysis. To evaluate nasal carriage, molecular characterization and effectiveness of decolonization of MRSA among patients receiving hemodialysis in Taiwan, we conducted this study.. From January to June 2011, two nasal samplings with a 3-month interval were obtained from patients undergoing hemodialysis in a medical center (CGMH), and in a local hospital (YMH) and sent for detection of MRSA. For MRSA carriers, decolonization procedures were administered. All patients in CGMH were observed if MRSA infections occurred during the study period.. A total of 529 nasal specimens (265 from CGMH and 264 from YMH) were collected from 296 patients (161 from CGMH and 135 from YMH). 233 patients participated in both surveys. Average one-time point MRSA carriage rate was 3.8%, and the rate was up to 6.9% for those with two-time point surveys. No additional significant factor for MRSA carriage was identified. Seventy percent of the 20 colonizing MRSA isolates, though categorized as healthcare-associated strains epidemiologically, shared common molecular characteristics of the local community-associated strains. Only one of the 20 MRSA-colonized patients failed decolonization and had persistent colonization, while without any intervention, 17 (61%) of 28 patients with methicillin-sensitive S. aureus colonization in the first survey had persistent colonization of a genetically indistinguishable strain. Within the study period, two patients (1.24%) in CGMH, one with MRSA colonization (9.1%), developed MRSA infection.. A substantial proportion of patients receiving hemodialysis in Taiwan had MRSA colonization, mostly genetically community strains. Decolonization procedures may effectively eliminate MRSA colonization and might reduce subsequent MRSA infection in these patients.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Female; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Typing; Nose; Prevalence; Renal Dialysis; Staphylococcal Infections; Taiwan; Young Adult

In Europe, methicillin-resistant Staphylococcus aureus (MRSA) belonging to the clonal complex (CC) 398 has become an important pathogen in horses, circulating in equine clinics and causing both colonization and infection. Whether equine MRSA is bound to hospitals or can also circulate in the general horse population is currently unknown. This study, therefore, reports the nasal and perianal MRSA screening of 189 horses on 10 farms in a suspected high prevalence region (East- and West-Flanders, Belgium).. Only one horse (0.53%) from one farm (10%) tested positive in the nose. It carried a spa type t011-SCCmecV isolate, resistant to β-lactams and tetracycline, which is typical for livestock-associated MRSA CC398.. In the region tested here, horses on horse farms seem unlikely to substantially contribute to the large animal associated ST398 MRSA reservoir present at intensive animal production units.

Topics: Animal Husbandry; Animals; Belgium; Carrier State; Disease Reservoirs; Female; Horse Diseases; Horses; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Staphylococcal Infections

Since the first report on methicillin resistant Staphylococcus aureus (MRSA) CC398 in pigs, several countries have determined the prevalence of MRSA-positive pig herds using different sampling and laboratory techniques. The objective of the study was to compare three sampling methods for MRSA-classification of herds. Therefore, nasal swabs of pigs and environmental wipes were collected from 147 herds with breeding pigs. Per herd, laboratory examination was done on 10 pools of 6 nasal swabs (NASAL), 5 single environmental wipes (ENVSINGLE) and one pool of 5 environmental wipes (ENVPOOL). Large differences in apparent prevalence of MRSA-positive herds between methods were found: 19.1% for ENVPOOL, 53.1% for ENVSINGLE, and 70.8% for NASAL. Pairwise comparisons of methods resulted in relative sensitivities of 26.9% (ENVPOOL vs. NASAL), 34.6% (ENVPOOL vs. ENVSINGLE), and 72.1% (ENVSINGLE vs. NASAL) with relative specificities of respectively 100%, 98.6% and 93.0%. Cohen's kappa was respectively 0.18, 0.32 and 0.55, thus varying between very poor and moderate agreement. Examination of environmental wipes is an easy and non-invasive method to classify herds for MRSA. The number of environmental wipes needed depends on e.g. required detection limits and within-herd prevalence. In low prevalent herds (e.g. herds with <3 positive pools of nasal swabs), 25 single environmental wipes are required to be 90% sure that MRSA is detected at a detection limit similar to analyzing 10 pools of nasal swabs. Individual analysis of environmental wipes is highly recommended, as pooling 5 environmental samples resulted in a substantial reduction of the apparent prevalence.

Topics: Animal Husbandry; Animals; Breeding; Environmental Microbiology; Epidemiologic Methods; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Reproducibility of Results; Sensitivity and Specificity; Staphylococcal Infections; Swine; Swine Diseases

Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage is a recognized risk factor for subsequent endogenous infections. However, the association between MRSA carriage and patient survival in hemodialysis patients has not been established.. In March 2007, this prospective cohort study enrolled 306 outpatients under maintenance hemodialysis from a hospital-based dialysis center in Taiwan. They received two consecutive weekly nasal swab cultures at the beginning of the study. Patients having at least one positive culture of MRSA were defined as MRSA carriers. Subjects were followed up until December 31, 2008. The primary outcome was all-cause mortality. Main secondary outcomes were infection-related mortality and morbidity.. We identified 29 MRSA carriers (9.48%) at study entry. After a median of 613 days of follow-up, Kaplan-Meier analysis showed significant survival differences between MRSA carriers and noncarriers (log-rank P = 0.02). Compared with noncarriers, MRSA carriers had a 2.46-fold increased risk of dying from any cause, after adjusting for covariates at the start of follow-up. The adjusted hazard ratios of infection-related mortality and occurrence of subsequent S. aureus infection in carriers were 4.99 and 4.31, respectively.. A major limitation is the relatively small sample size of MRSA carriers. Nevertheless, we demonstrated that there may be an association between MRSA nasal carriage and poor clinical outcomes in an outpatient hemodialysis population. This underscores the need for routine surveillance of MRSA nasal carriage and should alert the physicians of a group at high risk of morbidity and mortality.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Cohort Studies; Female; Humans; Kaplan-Meier Estimate; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prospective Studies; Renal Dialysis; Staphylococcal Infections

The co-existence of multiple genotypes in colonization by Staphylococcus aureus has not been fully investigated. The aim of this study was to evaluate the heterogeneity of S. aureus carriage in children. We evaluated 125 nasal and perianal swab samples that were positive for S. aureus from 76 children scheduled for elective surgery. For each sample, at least four colonies with the same or different morphotypes were selected for analysis. Multiple-locus variable-number tandem-repeat fingerprinting was used to determine the genetic relatedness and to characterize the clonality of the S. aureus strains. Of the 125 swabs, 91 (73 %) contained meticillin-sensitive S. aureus (MSSA), 8 (6 %) contained meticillin-resistant S. aureus (MRSA), and 26 (21 %) contained MSSA and MRSA simultaneously. A total of 738 S. aureus strains were evaluated with a mean of 6 colonies (range 4-15) picked from each culture. Of the 125 swabs, 32 (26 %) samples contained two genetically distinct S. aureus strains and 6 (5 %) contained three different genotypes. Multiple S. aureus strains simultaneously carried by individual children were genetically unrelated to each other. We concluded that the co-existence of multiple genotypes of S. aureus was common. The significance of multiple carriage is yet to be determined, but this intraspecies interplay could be important to pathogenicity and virulence in S. aureus.

Topics: Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cluster Analysis; DNA Fingerprinting; DNA, Bacterial; Genotype; Humans; Methicillin Resistance; Minisatellite Repeats; Molecular Typing; Nose; Perineum; Staphylococcal Infections; Staphylococcus aureus

We examined the relationship between the use of nasal continuous positive airway pressure (CPAP) and nasal colonization among low-birth-weight (LBW) infants. We prospectively cultured the nares of LBW infants on admission and weekly until hospital discharge. The modality of respiratory support during each culture was recorded. Bivariate and multivariate analyses were conducted to test the relationship between CPAP and nasal colonization. Analyses were repeated after stratifying infants into three birth-weight categories: 1500 to 2499 g, 1000 to 1499 g, and < 1000 g. In total, 766 nasal cultures were obtained from 167 infants. Nasal colonization with gram-negative bacilli was increased with the use of CPAP in all birth-weight categories ( P < 0.05) and with vaginal delivery in infants weighing < 1000 g and 1500 to 2499 g ( P = 0.04 and P = 0.02, respectively). Nasal colonization with any potential pathogen increased with the use of CPAP in all birth-weight categories ( P < 0.001), with the presence of chorioamnionitis in infants < 1000 g ( P = 0.055) and at younger gestational age in infants 1000 to 1499 g ( P = 0.0026). Caucasian infants 1500 to 2499 g had less colonization than infants of other races ( P = 0.01). Nasal CPAP is associated with increased colonization with gram-negative bacilli.

Topics: Bacteremia; Chorioamnionitis; Colony Count, Microbial; Continuous Positive Airway Pressure; Delivery, Obstetric; Female; Gestational Age; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Incidence; Infant, Low Birth Weight; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Logistic Models; Male; Nose; Pregnancy; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

In our recent experience with methicillin-resistant Staphylococcus aureus (MRSA) infections in 488 patients undergoing thoracic cardiovascular surgery, we found only 2 MRSA infections (one sternal and one graft site). Both patients received preoperative bacitracin and had a negative nares culture for MRSA before the initiation of bacitracin therapy. We conclude that preoperative MRSA screening cultures and bacitracin prophylaxis are neither clinically efficacious nor cost-effective in predicting or preventing MRSA in patients undergoing thoracic cardiovascular surgery.

Topics: Administration, Topical; Anti-Bacterial Agents; Carrier State; Cost-Benefit Analysis; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Mupirocin; Nose; Preoperative Care; Prevalence; Staphylococcal Infections; Thoracic Surgical Procedures

Children attending child care centers (CCCs) are at increased risk for infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). Nasal colonization often precedes infection, and MRSA colonization has been associated with increased infection risk. Community-associated MRSA (CA-MRSA) has caused increased MRSA infections in the general population, including children. Little is known about the frequency of MRSA nasal colonization in young children, particularly in those attending CCCs where disease transmission is common. We sampled the nares of 1,163 children in 200 classrooms from 24 CCCs in North Carolina and Virginia to assess S. aureus colonization. MRSA strains were molecularly analyzed for staphylococcal cassette chromosome mec (SCCmec) type, Panton-Valentine leukocidin status, and multilocus sequence type. A case-control study was performed to identify risk factors for MRSA colonization. We found that 18.1% children were colonized with S. aureus and 1.3% with MRSA. Molecular analysis of the MRSA strains identified 47% as CA-MRSA and 53% as health care-associated MRSA (HA-MRSA). Although two centers had multiple children colonized with MRSA, genotyping indicated that no transmission had occurred within classrooms. The case-control study did not detect statistically significant risk factors for MRSA colonization. However, MRSA-colonized children were more likely to be nonwhite and to have increased exposure to antibiotics and skin infections in the home. Both CA-MRSA and HA-MRSA strains were found colonizing the nares of children attending CCCs. The low frequency of colonization observed highlights the need for a large multicenter study to determine risk factors for MRSA colonization and subsequent infection in this highly susceptible population.

Topics: Bacterial Typing Techniques; Carrier State; Child Day Care Centers; Child, Preschool; Cluster Analysis; Female; Genotype; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Molecular Typing; Multilocus Sequence Typing; North Carolina; Nose; Polymorphism, Genetic; Prevalence; Risk Factors; Staphylococcal Infections; Virginia; Virulence Factors

The aim of this study was to determine the frequency of carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) among dogs admitted to a small animal hospital during a 17-month period, to characterize these isolates and to initially screen for possible factors associated with MRSP carriage. Swabs were taken from the nose/pharynx and the perineum as well as from wounds and skin infections (if present) of 814 dogs before entering the small animal hospital. A questionnaire for background information was completed. The staphylococcal species and methicillin resistance were confirmed pheno- and genotypically. The identified MRSP isolates were characterized by SCCmec typing, testing for susceptibility to 25 antimicrobial agents and SmaI-directed pulsed-field gel electrophoresis. A first screening for possible risk factors for MRSP carriage was performed by means of unifactorial contingency tables and CART analysis. Sixty (7.4%) dogs were positive for MRSP. All MRSP isolates harboured a type II-III SCCmec cassette and showed extended resistance to antimicrobial agents. Fifteen different SmaI patterns were observed. The major factors that clustered with MRSP carriage were former hospitalization and antibiotic treatment within the last six months before sampling. This study showed that only a minor part of the sampled dogs carried multi-resistant MRSP isolates. The facts that prior hospitalization and/or antibiotic therapy are potential associated factors for MRSP carriage underline the necessity of a judicious use of antibiotics in small animal medicine.

Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; Dog Diseases; Dogs; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Hospitals, Animal; Male; Methicillin Resistance; Nose; Perineum; Pharynx; Phenotype; Risk Factors; Skin Diseases; Staphylococcal Infections; Staphylococcus; Wounds and Injuries

In an asylum seeker centre in Schleswig-Holstein, a resident was diagnosed with furuncle caused by a Panton-Valentine leukocidine (PVL)-positive community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA). As a result of active case finding, 232 of 427 persons (54% of all residents) were screened for MRSA and two further PVL-positive CA-MRSA cases were identified

Topics: Adolescent; Adult; Aged; Animals; Bacterial Toxins; Community-Acquired Infections; Contact Tracing; Exotoxins; Female; Furunculosis; Germany; Humans; Leukocidins; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Molecular Typing; Nose; Polymerase Chain Reaction; Refugees; Somalia; Staphylococcal Infections; Young Adult

Staphylococcus epidermidis strains are frequently associated with catheter-related infection, acute bacteremia, and hospital-acquired infection. Some isolates produce an extracellular matrix called slime that may make them more resistant to antibiotics. The aim of this study was to determine antimicrobial resistance patterns, the prevalence of slime production, and the distribution of genes (mecA and aap, respectively) associated with these phenotypes in S. epidermidis nasal isolates from health-care personnel.. A descriptive cross-sectional study was performed on 163 nasal swabs from health-care staff (one swab per subject). S. epidermidis isolates were tested for slime production on congo red agar and antibiotic resistance. PCR-based screening for mecA and aap genes was performed upon the extracted DNA of S. epidermidis isolates.. A total of 99 S. epidermidis strains were cultured from 58.9% of the study participants (n = 96). Of these strains, 34 (34.3%) isolates produced slime. A significant relation between slime production and resistance to penicillin 32(94%) , oxacillin 30(88%), tetracycline 20(59%), erythromycin 27(79%), and clindamycin 26(77%) was found. Respectively, 95.8% and 94.8% of all isolates were PCR-positive for mecA and aap, but only 59.8% of mecA+ strains were oxacillin-resistant and 37.3% of aap+ strains were slime producers.. The surveillance of nasal colonization with slime-forming oxacillin-resistant S. epidermidis in health-care workers might be helpful in breaking the epidemiological chain of hospital-acquired infections.

Topics: Bacterial Proteins; Bacteriological Techniques; Carrier State; Cross-Sectional Studies; DNA, Bacterial; Female; Health Personnel; Humans; Male; Methicillin Resistance; Nose; Polymerase Chain Reaction; Polysaccharides, Bacterial; Staphylococcal Infections; Staphylococcus epidermidis; Virulence Factors

The duration of colonization with methicillin-resistant Staphylococcus aureus (MRSA) is not well known and there is debate as to whether a patient colonized with MRSA ever can be defined as 'MRSA-negative'.. Since 2003 all notified MRSA cases have been systematically followed in Skåne County, southern Sweden. Cultures are taken from the nares, throat, perineum and possible skin lesions. Contact tracing is conducted. The screening program continues as long as cultures are positive and then until 1 y of consecutive negative cultures for MRSA is completed.. Of the 578 MRSA cases during 2003-2006, 535 were included in this retrospective study. The median duration of colonization with MRSA was 5.9 months. Having household contacts with MRSA, young age, spa-type t002 and colonization in 2 or more locations, were significantly associated with a longer duration of colonization. Having a clinical infection treated with antibiotics (compared to clinical infection with no antibiotic treatment or asymptomatic carriage) was significantly associated with a shorter carriage time. Eradication treatment was associated with a shorter carriage time.. These results may have implications for the management of patients with MRSA carriage. The study indicates that MRSA carriage can be defined as 'negative' in a follow-up program and shows the importance of performing contact tracing among household members.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Perineum; Pharynx; Retrospective Studies; Skin; Staphylococcal Infections; Sweden; Time Factors; Young Adult

Oxoid Brilliance MRSA Agar and bioMérieux MRSA ID medium were evaluated for their ability to identify meticillin-resistant Staphylococcus aureus (MRSA) in clinical samples. Nasal and throat samples (n = 629) were taken from veterinarians and their household members. The sensitivities of Brilliance MRSA Agar and MRSA ID medium after 20 h of incubation were 63.6 and 64.5 %, and the specificities were 94.1 and 99.4 %, respectively. After an enrichment step, the sensitivities increased to 96.3 and 97.2 %, but the specificities decreased to 88.7 and 98.5 %, respectively. Brilliance MRSA Agar and MRSA ID medium are both sensitive methods for the screening of MRSA in combination with broth enrichment, but positive results require confirmation.

Topics: Animals; Anti-Bacterial Agents; Culture Media; Humans; Livestock; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Occupational Diseases; Occupational Exposure; Pharynx; Sensitivity and Specificity; Staphylococcal Infections; Swine; Veterinarians

Asymptomatic carriage of Staphylococcus aureus in healthy individuals has a high prevalence, especially in children and young adults. Nasal colonisation is a well-known risk factor for subsequent severe infection, or can be the source of transmission of this bacterium to other susceptible persons. In this study, we have surveyed the nasal carriage rate of students of the Semmelweis University, by screening 300 volunteers. We have determined the antibiotic sensitivity of the isolates by Etest, and their genetic relatedness by pulsed-fieled gel electrophoresis. The nasal carriage rate of S. aureus was found to be 29.3%, and that of MRSA only 0.67% (2/300). The isolates were generally sensitive to antibiotics, except for macrolides. We could observe a noticeably great genetic diversity, even among strains deriving from students of the same university group.

Topics: Anti-Bacterial Agents; Carrier State; Electrophoresis, Gel, Pulsed-Field; Humans; Hungary; Microbial Sensitivity Tests; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Students; Universities; Young Adult

Persistent nasal carriage of Staphylococcus aureus is the primary reservoir for this pathogen and a risk factor for infection. The nares of 12 to 30% of healthy individuals are persistently colonized with staphylococci. Elucidating the yet enigmatic determinants of this phenomenon is of major public health interest. We hypothesized that differences in the levels of antimicrobial peptides (AMPs) that are found in human skin and have pronounced antistaphylococcal activity may contribute to this phenomenon. We compared constitutive and induced mRNA levels of RNase 7 and human β-defensin 3 (HBD-3) in healthy and experimentally wounded gluteal skin of 60 volunteers after ascertaining their carrier status through repeated nasal cultures. We found that levels of HBD-3 expression in skin of persistent nasal carriers of S. aureus were lower: induced levels in carriers were 63% (95% confidence interval, 43 to 94%; P = 0.02) and constitutive levels were 76% (95% confidence interval, 52 to 110%; P = 0.14) of those found in noncarriers. No such associations were present for RNase 7. In conjunction with existing knowledge, these findings suggest that healthy individuals with deficient HBD-3 expression in keratinocytes are more prone to persistent nasal colonization with S. aureus.

Topics: Adult; beta-Defensins; Carrier State; Female; Humans; Immunity, Innate; Male; Nasal Cavity; Nasal Mucosa; Nose; Ribonucleases; RNA, Messenger; Skin; Staphylococcal Infections; Staphylococcus aureus; Wound Healing

A novel chromogenic medium for the detection of methicillin-resistant Staphylococcus aureus (MRSA), ChromID MRSA New, was evaluated and compared with the original ChromID MRSA agar, using 355 consecutive screening specimens from nose (120), throat (121) and perineum (114). The specimens were collected with an E-swab and inoculated within 24 hours onto both ChromID MRSA New and on ChromID MRSA. ChromID MRSA New was more sensitive than ChromID MRSA in detecting MRSA after 24 hours of incubation (94.3% versus 81.4%; p < 0.05). With the ChromID MRSA New, processing time is reduced from 48 h to 24 h and confirmation of the resistance to methicillin is redundant.

Topics: Bacteriological Techniques; Carrier State; Chromogenic Compounds; Culture Media; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Perineum; Pharynx; Sensitivity and Specificity; Staphylococcal Infections; Time Factors

The Newcastle upon Tyne Hospitals NHS Foundation Trust (NuTH) implemented a seek and destroy (S&D) programme in 2006 to minimise meticillin-resistant Staphylococcus aureus (MRSA) colonisation and/or infection of patients. Using a phased introduction, all patient specialties were included in the scheme by September 2008, well in advance of the mandatory Department of Health, England (DoH) requirement for all patients to be screened. NuTH screens nose, throat and perineum samples from approximately 15,000 patients per month using a chromogenic culture method, showing a mean MRSA prevalence of 2.4%. Provision of seven-day microbiology and infection control services ensured that the turnaround time to prescribing decolonisation therapy was <24 h. Analysis of 168,073 results identified the necessity for inclusion of all three screening sites to maximise recovery of MRSA. Appraisal of the S&D policy demonstrated that MRSA detection rates did not increase despite an exponential increase in workload owing to mandatory inclusion of low risk areas in the screening programme. Review of data during a typical one-month period indicated that only seven day-case patients would not have been identified as MRSA carriers using our targeted S&D approach compared with the DoH universal screening. Detection of these additional patients incurred total laboratory costs of £20,000 and generated a further 4200 associated negative screens in one month alone. Our study indicates that a screening strategy based upon clinical risk is more pragmatic and more cost-effective than the universal programme currently required in England.

Topics: Bacteriological Techniques; Carrier State; Chromogenic Compounds; Culture Media; England; Hospitals, Teaching; Humans; Infection Control; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Perineum; Pharynx; Prevalence; Program Evaluation; Staphylococcal Infections

In this study, we aimed to determine the nasal carriage rate of Staphylococcus aureus and risk factors in hemodialysis (HD) patients.. One hundred eighty-four HD patients were evaluated. A second sample was taken from the subjects, the wipe samples of whom were isolated as S. aureus. And subjects whose second samples' results were the same were deemed as S. aureus carriers.. Fifty-two (28.3%) patients were identified as S. aureus carriers. In the control group, S. aureus carriage has been found out as 14.9% in 116 healthy subjects. The isolation rate of S. aureus has been found statistically significantly high in the age group of 41-61 years. But, methicillin-resistant S. aureus (MRSA) isolation ratio has been statistically high in the group over the age of 61 years. Sepsis history and gastrointestinal system disease development is closely related to bacterial isolation. MRSA isolation ratios have been found high in chronic lung disease patients, diabetic patients, patients with infection history, and patients with impaired general state of health. The carriage ratios have been found higher in the patients who are settled in urban areas, are subjected to dialysis for more than 10 years, and are hospitalized in the past year. However, the difference between the other groups is not statistically significant.. S. aureus carriage must be screened on regular intervals in HD patients. Nasal S. aureus carriage follow-up and treatment is a process that will protect patients from more severe clinical pictures.

Topics: Adult; Aged; Carrier State; Drug Resistance, Bacterial; Female; Humans; Kidney Failure, Chronic; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Turkey

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Carrier State; Drug Resistance, Bacterial; Feces; Livestock; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Swine; Swine Diseases; Thailand

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a community pathogen. Community-associated (CA) MRSA infections have occurred among multiple members of a household. We describe the incidence of and risk factors for MRSA colonization among household contacts of children with CA-MRSA infections.. MRSA-infected children <18 years of age who lacked established healthcare-associated MRSA risk factors were identified through surveillance at 12 Minnesota hospital laboratories. Nasal swab specimens and information on medical history and hygiene behaviors were collected from case-patients and enrolled household contacts during home visits. S. aureus isolates obtained from nasal cultures were screened for oxacillin resistance.. In all, 236 households consisting of 236 case-patients and 712 household contacts were enrolled. Home visits were conducted on an average of 69 days after the onset of symptom in case-patients (range: 16-178 days). Twenty-nine (13%) case-patients and 82 (12%) household contacts had MRSA nasal colonization. Nasal MRSA colonization in ≥ 1 household contact occurred in 58 (25%) households. Household contacts who assisted the case-patient to bathe or who shared balms/ointments/lotion with the case-patient were more likely to be colonized (P < 0.01, P < 0.05), whereas those who reported using antibacterial versus nonantibacterial soap for hand washing were less likely to be colonized (P < 0.05) with MRSA clonally related to the case-patient infection isolate.. Only 13% of case-patients had MRSA nasal colonization on an average of 69 days after their initial MRSA infection. CA-MRSA colonization may be short-lived or may occur at non-nasal sites. One quarter of households had at least one household contact colonized with MRSA. Modifiable behaviors, such as sharing personal items, may contribute to transmission.

Topics: Adolescent; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Family Characteristics; Female; Hand Disinfection; Humans; Incidence; Infant; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Minnesota; Nose; Oxacillin; Population Surveillance; Risk Factors; Staphylococcal Infections

This study investigated the transmission dynamics of meticillin-resistant Staphylococcus aureus (MRSA) in a tertiary referral surgical unit with 300 beds. All adult patients were actively screened for MRSA by culture at hospital admission and twice weekly thereafter during hospitalisation from 1 October to 31 December 2008. The colonisation pressure per 1000 patient-days and the incidence density of nosocomial MRSA transmission per 1000 colonisation-days were calculated for the different spa types of MRSA. In total, 6619 nasal swabs were obtained from 2289 patients. One-hundred and forty-eight (7%) patients had MRSA in nasal swabs at admission screening, of which 68/148 (46%) were residents of elderly care homes. Fifty-two of 2141 (2%) patients had conversion of nasal MRSA carriage status from negative to positive during hospitalisation. Among the 200 patients with MRSA, spa types t1081 and t037 were found in 99 (50%) and 30 (15%) patients, respectively. The colonisation pressure per 1000 patient-days was 40.9 for t0181, 22.2 for t037 and 26.3 for the less common spa types. The incidence densities of nosocomial MRSA transmission per 1000 colonisation-days were significantly higher for t1081 (28.5 vs 4.0, P<0.01) and t037 (21.5 vs 4.0, P=0.03) compared with the less common spa types. Proactive screening of MRSA in patients from elderly care homes and targeted isolation of these patients, especially those carrying spa types with high transmissibility, are important for the control of MRSA in hospitals.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Typing Techniques; Carrier State; Cross Infection; Female; Hong Kong; Hospital Units; Hospitals, University; Humans; Incidence; Infection Control; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Staphylococcal Infections; Staphylococcal Protein A; Surgery Department, Hospital

Topics: Agar; Animals; Anti-Bacterial Agents; Bacteriological Techniques; Carrier State; Culture Media; Ear; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Oxacillin; Sacrum; Sensitivity and Specificity; Staphylococcal Infections; Swine

In 2005, methicillin-resistant Staphylococcus aureus was found in pig herds and in humans in contact with pigs. To determine the prevalence of, this now-called livestock-associated (LA) MRSA among pig herds in The Netherlands and to identify and quantify risk factors, an observational study of 202 pig herds was performed between 2007 and 2008. Five environmental wipes and 60 nasal swabs from each herd were collected, and microbiological analysis was performed on single environmental samples and pooled nasal samples. A herd was considered MRSA-positive if ≥1 sample tested positive. The prevalence of MRSA-positive herds was 67% in breeding herds and 71% in finishing herds. Multivariable logistic regression analysis was then performed on data from 171 breeding herds. The number of MRSA-positive herds increased from ∼30% at the start to ∼75% at the end of the study, most likely due to transmission between herds. The prevalence of MRSA increased with herd size, as ∼40% of smaller herds (<250 sows) were MRSA-positive compared to >80% of larger herds (>500 sows). Other risk factors (e.g. antimicrobial use, purchase of gilts and hygiene measures) were not significantly associated with MRSA, though associated with herd size. Herd size appeared to be a compilation of several factors, which made larger herds more often MRSA positive.

Topics: Animals; Anti-Bacterial Agents; Bacterial Typing Techniques; Environmental Microbiology; Female; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Netherlands; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Sus scrofa; Swine; Swine Diseases

The prevalence of meticillin-resistant Staphylococcus aureus (MRSA) carriage at hospital admission in The Netherlands was 0.03% in 1999-2000. The aim of the present study was to assess whether the prevalence of MRSA carriage in The Netherlands has changed over the last few years. In five Dutch hospitals, 6496 unique patients were screened for nasal S. aureus carriage at hospital admission by microbiological culture between 1 October 2005 and 7 June 2007. In total, 2036 of 6496 (31.3%) patients carried S. aureus in their nose, and seven of 6496 (0.11%) patients were nasal carriers of MRSA. Compared with 1999-2000, the prevalence of MRSA carriage in the Dutch population at hospital admission has increased more than three fold; however, this increase was not significant (P=0.06, Fisher's exact test). This prevalence is still among the lowest in the world, probably as a result of the stringent Dutch infection control policy, and the restrictive use of antibiotics in The Netherlands.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Female; Hospitalization; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Netherlands; Nose; Patient Admission; Prevalence; Staphylococcal Infections; Staphylococcus aureus

The activity of ACHN-490 was evaluated against 493 meticillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2009-2010 from 23 US hospitals. The MIC(50) and MIC(90) values (minimal inhibitory concentrations for 50% and 90% of the organisms, respectively) for ACHN-490 were 1 and 2 μg/mL compared with 8 and 32 μg/mL for amikacin, 0.5 and 1 μg/mL for gentamicin and 2 and >16 μg/mL for tobramycin. The gene encoding the aminoglycoside-modifying enzyme APH(2″)-Ia/AAC(6')-Ie was present in 12% of the subset of 84 isolates examined by polymerase chain reaction (PCR), whilst the gene encoding ANT(4')-Ia was present in 89% of isolates. ACHN-490 activity was not affected by either enzyme.

Topics: Aminoglycosides; Anti-Bacterial Agents; Blood; Drug Resistance, Bacterial; Hospitals; Humans; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Sisomicin; Staphylococcal Infections; Tobramycin; United States

To describe the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) carriage and transmission in an ambulatory hemodialysis population.. Prospective cohort study.. Outpatient hemodialysis facility affiliated with a large academic medical center.. Of the 170 facility patients, 103 (61%) participated in the study.. Swab specimens of the nares, axillae, and vascular access site were collected from participants weekly for 3 weeks and then monthly for 5 months. Demographic and clinical data were collected monthly for 12 months. Molecular analysis of MRSA isolates was performed.. The baseline MRSA carriage prevalence was 12%. Factors associated with MRSA carriage included a history of MRSA; failed renal transplantation; hospital admission within 6 months; and receipt of a first-generation cephalosporin, cefepime, or vancomycin. Six subjects acquired MRSA after enrollment (incidence, 1.2 per 100 patient-months at-risk; overall prevalence, 18%). Molecular analysis suggested that transmission occurred within the facility. The incidence of MRSA infection among carriers was 1.76 per 100 patient-months. Community-associated strains (ie, USA300) were isolated from 28% of carriers and at least 25% of infections.. The prevalence of MRSA carriage and the incidence of infection among carriers were high among ambulatory hemodialysis patients, and community-associated MRSA was responsible for a large portion of the MRSA burden. A relatively high rate of MRSA acquisition was observed, with indirect evidence of intrafacility transmission. Additional studies are needed to confirm these findings and to identify effective and feasible methods to prevent MRSA transmission and infection among hemodialysis patients.

Topics: Adult; Aged; Aged, 80 and over; Ambulatory Care; Axilla; Bacterial Typing Techniques; Carrier State; Catheters, Indwelling; Community-Acquired Infections; Cross Infection; Female; Humans; Incidence; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Renal Dialysis; Renal Insufficiency, Chronic; Staphylococcal Infections; Staphylococcal Protein A

Topics: Adult; Aged; Anti-Bacterial Agents; Anti-Infective Agents, Local; Antibiotic Prophylaxis; Chlorhexidine; Drug Resistance, Bacterial; Female; Hexachlorophene; Humans; Male; Medication Adherence; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Mupirocin; Nose; Postoperative Complications; Staphylococcal Infections; Surveys and Questionnaires

Nasal Staphylococcus aureus is a major source of community and hospital associated staphylococcal infections. This study determined the prevalence of nasal S. aureus isolates and investigated their antimicrobial resistance profile in healthy volunteers.. Nasal specimens of healthy volunteers in Amassoma were cultured and screened for S. aureus using standard microbiological protocols and their antibiotic profile susceptibility was investigated using disc diffusion and agar dilution techniques.. A total of 40 (33.3%) S. aureus isolates were obtained from 120 nares specimens screened. Twenty three (57.5%) and 17 (42.5%) of the isolates were from university students and villagers respectively. The isolates showed an overall 75% resistance to ampicillin, 52.5% to doxycycline, 47.5% to chloramphenicol, 35% to erythromycin and 32.5% to cotrimoxazole; with 27.5% methicillin resistant. No isolate was resistant to gentamicin while few isolates were resistant to cefuroxime (2.5%), augmentin (5.0%), ciprofloxacin (10.0%), ofloxacin (10.0%) and vancomycin (7.5%). Twenty one (52.5%) of all the isolates were multi-drug resistant, ten (47.6%) of which were methicillin resistant Staphylococcus aureus (MRSA) and only 3 (7.5%) were fully susceptible to all the tested antimicrobial drugs.. The observation calls for strategies to prevent their spread to more vulnerable populations where the consequences of their infections can be severe.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Carrier State; Drug Resistance, Multiple, Bacterial; Female; Humans; Male; Microbial Sensitivity Tests; Nigeria; Nose; Prevalence; Sex Distribution; Socioeconomic Factors; Staphylococcal Infections; Staphylococcus aureus; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) colonization is a predictor of subsequent infection in hospitalized adults. The risk of subsequent MRSA infections in hospitalized children colonized with MRSA is unknown.. Children admitted to an academic medical center's pediatric intensive care unit between March 2007 and March 2010 were included in the study. Anterior naris swabs were cultured to identify children with MRSA colonization at admission. Laboratory databases were queried and National Healthcare Safety Network definitions applied to identify patients with MRSA infections during their hospitalization or after discharge.. The MRSA admission prevalence among 3140 children was 4.9%. Overall, 56 children (1.8%) developed an MRSA infection, including 13 (8.5%) colonized on admission and 43 (1.4%) not colonized on admission (relative risk [RR], 5.9; 95% confidence interval [CI], 3.4-10.1). Of those, 10 children (0.3%) developed an MRSA infection during their hospitalization, including 3 of 153 children (1.9%) colonized on admission and 7 of 2987 children (0.2%) not colonized on admission (RR, 8.4; 95% CI, 2.7-25.8). African-Americans and those with public health insurance were more likely to get a subsequent infection (P < .01 and P = .03, respectively). We found that 15 children acquired MRSA colonization in the pediatric intensive care unit, and 7 (47%) developed a subsequent MRSA infection.. MRSA colonization is a risk factor for subsequent MRSA infection in children. Although MRSA colonized children may have lower risks of subsequent infection than adults, children who acquire MRSA in the hospital have similarly high rates of infection. Preventing transmission of MRSA in hospitalized children should remain a priority.

Topics: Academic Medical Centers; Carrier State; Child; Child, Preschool; Critical Illness; Female; Humans; Infant; Intensive Care Units, Pediatric; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Risk Factors; Staphylococcal Infections

Nasal colonization with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is being increasingly reported, especially in places where people are in close contact and in reduced hygiene, such as day-care centers. In this study we investigated the frequency of MRSA colonization and their antibiotic susceptibility patterns in 1-6 years old children of day-care centers in Hamadan, West of Iran.Five hundred nasal swabs were collected from children of 27 day-care centers that had no risk factors for colonization by S. aureus. The specimens were cultured for isolation of S. aureus by standard methods. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. For evaluation of the frequency of erythromycin induced clindamycin resistance, disk approximation test (D-test) was applied.Totally, 148 (29.6%) children were colonized by S. aureus. Out of 260 male, 94 (36.2%) and of 240 female, 54 (22.5%) cases were nasal carriers of S. aureus (P value = 0.001). Six (4.1%) of the 148 S. aureus isolated from children were MRSA strains. None of MRSA and methicillin susceptible S. aureus (MSSA) was resistant to vancomycin and clindamycin. Three of the 6 strains of MRSA and 7 (4.9%) of the 142 MSSA strains were resistant to erythromycin, and D-test was positive in all of them.We conclude that the rate of colonization by S. aureus is high in children attending day-care centers but colonization with MRSA is not common in our areas. Clindamycin or trimethoprim-sulfamethoxazol could be used in mild to moderataly severe diseases caused by CA-MRSA. However, if the CA-MRSA isolates are erythromycin resistant, D-test should be carried out for detection of inducible clindamycin resistance.

Topics: Anti-Bacterial Agents; Carrier State; Child; Child Day Care Centers; Child, Preschool; Clindamycin; Community-Acquired Infections; Erythromycin; Female; Humans; Infant; Iran; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Prevalence; Staphylococcal Infections; Sulfamethoxazole; Surveys and Questionnaires; Trimethoprim

We compared recovery of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from nasal and groin swab specimens of 600 HIV-infected outpatients by selective and nonselective direct plating and broth enrichment. Swabs were collected at baseline, 6-month, and 12-month visits and cultured by direct plating to mannitol salt agar (MSA) and CHROMagar MRSA (CM) and overnight broth enrichment with subculture to MSA (broth). MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), staphylococcal cassette chromosome mec (SCCmec) typing, and PCR for the Panton-Valentine leukocidin. At each visit, 13 to 15% of patients were colonized with MRSA and 30 to 33% were colonized with methicillin-susceptible S. aureus (MSSA). Broth, CM, and MSA detected 95%, 82%, and 76% of MRSA-positive specimens, respectively. MRSA recovery was significantly higher from broth than CM (P ≤ 0.001) or MSA (P ≤ 0.001); there was no significant difference in recovery between MSA and CM. MSSA recovery also increased significantly when using broth than when using MSA (P ≤ 0.001). Among specimens collected from the groin, broth, CM, and MSA detected 88%, 54%, and 49% of the MRSA-positive isolates, respectively. Broth enrichment had a greater impact on recovery of MRSA from the groin than from the nose compared to both CM (P ≤ 0.001) and MSA (P ≤ 0.001). Overall, 19% of MRSA-colonized patients would have been missed with nasal swab specimen culture only. USA500/Iberian and USA300 were the most common MRSA strains recovered, and USA300 was more likely than other strain types to be recovered from the groin than from the nose (P = 0.05).

Topics: Bacterial Toxins; Bacteriological Techniques; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Genotype; Groin; HIV Infections; Humans; Leukocidins; Methicillin-Resistant Staphylococcus aureus; Molecular Typing; Nose; Outpatients; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections

Methicillin-resistant S. aureus emerged in recent decades to become a leading cause of infection worldwide. Colonization with MRSA predisposes to infection and facilitates transmission of the pathogen; however, available regimens are ineffective at preventing MRSA colonization. Studies of human nasal flora suggest that resident bacteria play a critical role in limiting S. aureus growth, and prompted us to query whether application of commensal resident bacteria could prevent nasal colonization with MRSA. We established a murine model system to study this question, and showed that mice nasally pre-colonized with S. epidermidis became more resistant to colonization with MRSA. Our study suggests that application of commensal bacteria with antibiotics could represent a more effective strategy to prevent MRSA colonization.

Topics: Administration, Intranasal; Animals; Humans; Methicillin-Resistant Staphylococcus aureus; Mice; Nose; Staphylococcal Infections; Staphylococcus epidermidis

In the hemodialysis population, the incidence of Staphylococcus aureus colonization has been documented to be as high as 80%; effective prophylaxis of vascular access infection and bacteremia is a worthwhile goal in the management of hemodialysis population. Surveillance of 50 hemodialysis patients for S. aureus-positive nasal cultures was performed by monthly nasal swabs over a 12-month period. All patients were performing dialysis using hemodialysis catheters thrice weekly. All positive cultures were treated with a prophylactic antibiotic regimen. Thirty-one patients (62%) had one or more positive cultures. The surveillance period was longer in the S. aureus nasal carriers (p < 0.01). The frequency of positive cultures correlated with the duration of surveillance (p < 0.05). The incidence of S. aureus bacteremia was greater in patients with three or more positive cultures (p < 0.05). This study suggests that continuous surveillance for S. aureus nasal colonization is essential to properly identify all hemodialysis patients using catheters at risk of developing S. aureus bacteremias.

Topics: Adult; Anti-Bacterial Agents; Bacteremia; Catheters; Catheters, Indwelling; Equipment Contamination; Female; Humans; Male; Middle Aged; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Orthopaedic patients with poor nutritional status are at an increased risk of postoperative complications, such as infection and wound healing. Nasal colonization with Staphylococcus aureus, especially with methicillin-resistant Staphylococcus aureus, has been shown to be a risk factor for surgical-site infections. We examined the incidence of nutritional depletion in our arthroplasty population and its correlation with Staphylococcus aureus colonization. We conducted a retrospective review of prospectively collected data of our arthroplasty patient population. Patients with known Staphylococcus aureus colonization or surgical-site infection were compared with a random cohort of patients. Patient demographics, preoperative nasal culture, and two nutritional screening scores were collected. Six hundred and fifty-two patients underwent arthroplasty and completed preoperative nasal cultures and nutritional assessment. A high percentage (27%) of our patients demonstrated some level of nutritional depletion prior to joint replacement. Overall nutritional scores were not significantly associated with surgery-type, preoperative nasal culture, or surgical- site infection in our patient population.

Topics: Adult; Aged; Aged, 80 and over; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Bacteriological Techniques; Chi-Square Distribution; Female; Humans; Logistic Models; Male; Malnutrition; Methicillin-Resistant Staphylococcus aureus; Middle Aged; New York City; Nose; Nutrition Assessment; Nutritional Status; Odds Ratio; Retrospective Studies; Risk Assessment; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Treatment Outcome

Although the effect of Staphylococcus aureus (SA) decolonization on surgical site infection (SSI) rates has been studied, patient tolerance and acceptance of these regimens has not been assessed. Surgical patients at our hospital's Pre-Admission Testing Clinic (PAT) receive SA reduction protocols instructing the preoperative use of chlorhexidine gluconate (CHG) soap and intranasal mupirocin ointment (MO). Certain insurers do not cover MO costs resulting in out of pocket (OOP) expenses for some patients.. This study assessed patient attitudes and compliance with our hospital's SA decolonization regimen.. One-hundred-forty-six patients received surveys. Descriptive statistics were used for analysis.. Of respondents fitting inclusion criteria, 81% followed the MO protocol (MO users) while 89% followed the CHG protocol (CHG users). Fifty-four percent of MO users reported OOP expenses and 13% reported a hard or very hard financial burden. Ninety-three percent of CHG users reported the protocol was easy or very easy to follow.. Eighty-one percent of patients receiving the SA protocol were fully compliant despite cost or difficulty obtaining MO. Given these barriers and some difficulty with CHG application, we hypothesize compliance may be improved if MO is provided to patients without OOP expenses and if the CHG application method is simplified.

Topics: Administration, Intranasal; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Anti-Infective Agents, Local; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Chlorhexidine; Female; Hand Disinfection; Health Care Costs; Health Expenditures; Health Knowledge, Attitudes, Practice; Humans; Infection Control; Insurance, Health, Reimbursement; Male; Middle Aged; Mupirocin; New York City; Nose; Patient Compliance; Program Evaluation; Soaps; Spine; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Treatment Outcome; Young Adult

Nasal carriage of Staphylococcus aureus contributes to an increased risk of developing an infection with the same bacterial strain. Genetic regulatory elements and toxin-expressing genes are virulence factors associated with the pathogenic potential of S. aureus. We undertook an extensive molecular characterization of methicillin-susceptible S. aureus (MSSA) carried by children. MSSA were recovered from the nostrils of children. The presence of Panton-Valentine leukocidin (PVL), exfoliatins A and B (exfoA and exfoB), and the toxic-shock staphylococcal toxin (TSST-1) and agr group typing were determined by quantitative PCR. A multiple-locus variable-number of tandem repeat analysis (MLVA) assay was also performed for genotyping. Five hundred and seventy-two strains of MSSA were analysed. Overall, 30% were positive for toxin-expressing genes: 29% contained one toxin and 1.6% two toxins. The most commonly detected toxin gene was tst, which was present in 145 (25%) strains. The TSST-1 gene was significantly associated with the agr group 3 (OR 56.8, 95% CI 32.0-100.8). MLVA analysis revealed a large diversity of genetic content and no clonal relationship was demonstrated among the analysed MSSA strains. Multilocus sequence typing confirmed this observation of diversity and identified ST45 as a frequent colonizer. This broad diversity in MSSA carriage strains suggests a limited selection pressure in our geographical area.

Topics: Anti-Bacterial Agents; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cluster Analysis; Female; Genotype; Humans; Infant; Male; Methicillin; Minisatellite Repeats; Molecular Epidemiology; Molecular Typing; Nose; Staphylococcal Infections; Staphylococcus aureus; Switzerland; Virulence Factors

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging concern in infectious disease practice. Although MRSA infections occur in a wide variety of anatomic sites, the majority of studies considering the risk factors for methicillin resistance among S. aureus infections have focused on MRSA bacteremia.. To describe risk factors associated with methicillin resistance among S. aureus infections at different anatomic sites.. We collected information on the demographic and clinical characteristics of patients examined at the Atlanta Veterans Affairs Medical Center with S. aureus infections during the period from June 2007 through May 2008. We used multivariate logistic regression to describe factors significantly associated with methicillin resistance.. There were 568 cases of S. aureus infection among 528 patients. We identified 352 cases (62%) of MRSA infection and 216 cases (38%) of methicillin-sensitive S. aureus infection. The adjusted odds of methicillin resistance were higher among infections that occurred among patients who had a prior history of MRSA infection (odds ratio [OR], 3.9 [95% confidence interval {CI}, 2.3-6.4]) or resided in a long-term care facility during the past 12 months (OR, 2.0 [95% CI, 1.0-4.0]) but were lower for infections that occurred among patients who had undergone a biopsy procedure during the past 12 months (OR, 0.7 [95% CI, 0.6-0.9]). Most cases of infection were community-onset infections (523 [92%] of 568 cases), and about one-half (278 [49%]) were not healthcare associated.. Compared with previous studies of methicillin resistance among patients with S. aureus bacteremia, we found similar factors to be associated with methicillin resistance among S. aureus isolates recovered from more diverse anatomic sites of infection. Of note, nearly one-half of our cases of MRSA infection were not healthcare associated.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Boston; Carrier State; Female; Hospitals, Veterans; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Oropharynx; Prevalence; Risk Factors; Staphylococcal Infections; Veterans; Young Adult

An exploratory study of methicillin-resistant Staphylococcus aureus (MRSA) and SCCmec elements in bacteria along the Mexican border of south Texas was performed. Between September and December of 2008, 375 swabs of anterior nares were self-collected by students attending the University of Texas-Pan American (UTPA) and cultured for MRSA. Fifty seven bacterial isolates were kept for further analysis that included suspected MRSA and other SCCmec-containing bacteria. Isolates were examined for the presence of nuc, mecA, lukS-PV, and spa genes using PCR. SCCmec and spa typing were also performed. Seven S. aureus isolates were found of which six were classified as MRSA. SCCmec typing showed five of the six MRSA strains to be type IV, while one MRSA strain, and most of the non-S. aureus strains, were untypeable, producing results that were indicative of mixed SCCmec types. Five of the six MRSA strains contained known spa types (two of which corresponded to USA300 and one to USA600), while one strain had a novel spa type. Only one isolate, a USA300 MRSA, was positive for lukS-PV. Easy access by the Texas border community to antibiotics in Mexico without a prescription, and the strong partition in SCCmec types between MRSA and non-S. aureus bacteria suggest that this border region of Texas may be uniquely suited for the study of emerging SCCmec types, their horizontal transfer, and perhaps other aspects of antibiotic resistance in bacteria.

Topics: Adolescent; Bacterial Typing Techniques; Carrier State; Child; Community-Acquired Infections; DNA Fingerprinting; DNA, Bacterial; Genes, Bacterial; Genotype; Humans; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcal Protein A; Texas; Young Adult

The increasing prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains together with their disease impact on hospital patients and individuals in the community has posed a major challenge to healthcare workers. This study examined the prevalence of S. aureus nasal carriage, antimicrobial susceptibility patterns, and possible risk factors in the community. Of 500 studied subjects (aged from 6 to 65 years) in Lebanon, the overall S. aureus nasal carriage rate was 38.4%, the highest (57.1%) being in children aged 6-10 years. Only eight individuals (1.6%) were carriers of MRSA. Risk factors for S. aureus nasal colonization were male gender, young age, contact with healthcare workers, use of needle injections, and having asthma. A significant decrease in colonization rate was associated with nasal wash with water, use of nasal sprays, and the presence of acne. These findings may assist in better understanding of control measures to decrease nasal colonization with S. aureus in Lebanon and elsewhere.

Topics: Adolescent; Adult; Age Factors; Aged; Asthma; Carrier State; Child; Community-Acquired Infections; Female; Health Personnel; Humans; Injections; Lebanon; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Risk Factors; Sex Factors; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To evaluate the prevalence of and risk factors for extranasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and its relationship to nasal colonization among veterans hospitalized for acute care.. Prospective observational study.. Veterans Affairs (VA) acute care hospital in Boston, Massachusetts.. Convenience sample of 150 patients hospitalized within the previous 36 hours and screened for nasal MRSA who were not known to have an active MRSA infection or MRSA isolates recovered from a wound during the past 12 months.. Potential risk factors for MRSA colonization were assessed, and oropharynx, axilla, hand, perirectal, wound, and catheter insertion site samples were obtained for culture. MRSA was identified in chromogenic agar and confirmed by use of routine culture techniques. Nasal MRSA colonization was detected by means of polymerase chain reaction (PCR).. Nasal swab samples analyzed by use of PCR yielded results positive for MRSA in 16 (11%) of 150 patients. Extranasal cultures yielded positive results for 3 (2%) of 134 patients who tested negative for nasal MRSA colonization and for 9 (56%) of 16 patients who tested positive for nasal MRSA colonization (odds ratio [OR], 56.1 [95% confidence interval {CI}, 12.4-254.6]; p < .001). The oropharynx was the most commonly colonized extranasal site (10 patients [7%]). Independent risk factors for extranasal MRSA colonization included nasal MRSA colonization (OR, 66.9 [95% CI, 11.8-379.7]; P < .001) and end-stage hepatic disease (OR, 98.5 [95% CI, 3.1-3,112.4]; P = .01).. Extranasal MRSA colonization is infrequent among veterans admitted for acute care to VA Boston Healthcare System. Extranasal MRSA colonization was strongly associated with nasal MRSA colonization, which suggests that the VA MRSA Prevention Initiative is not missing a large number of MRSA-colonized patients by focusing on nasal-only screening.

Topics: Adult; Aged; Aged, 80 and over; Boston; Carrier State; Cross Infection; Female; Hand; Hospitals, Veterans; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Oropharynx; Patient Admission; Polymerase Chain Reaction; Prevalence; Rectum; Staphylococcal Infections; Wounds and Injuries; Young Adult

Topics: Animals; Carrier State; Dog Diseases; Dogs; Nose; Pharynx; Rectum; Staphylococcal Infections; Staphylococcus aureus

In the aftermath of a methicillin-resistant Staphylococcus aureus (MRSA) ST22 hospital outbreak, we investigated the prevalence of long-term carriage, the efficacy of MRSA decolonization treatment (DT) and the spread of MRSA to households of patients and healthcare workers (HCWs). Furthermore, we evaluated the efficacy of repeated DT in long-term MRSA carriers. Of 250 index persons (58 HCWs and 192 patients), 102 persons (19 HCWs and 83 patients) and 67 household members agreed to participate. Samples from all 169 persons were taken from the nose, throat, wounds and devices/catheters, and urine samples were additionally taken from index persons. Samples from companion animals (n = 35) were taken from the nostrils and anus. Environmental sites (n = 490) screened were telephone, television remote control, toilet flush handle, favourite chair and skirting board beside the bed. Sixteen (19%) patients and two household members, but no HCWs, were ST22-positive. The throat was the most frequent site of colonization. In a multivariate analysis, chronic disease (p <0.001) and pharyngeal carriage (p <0.001) were associated with long-term MRSA carriage. MRSA was found in the environments of four long-term carriers. All animals tested were negative. MRSA-positive households were decolonized using nasal mupirocin TID and daily chlorhexidine body and hair wash for 5 days. Pharyngeal MRSA carriers also received fucidic acid (500 mg TID) combined with rifampicin (600 mg BID) or clindamycin (600 mg BID) for 7 days. The home environment was cleaned on days 2 and 5. At the end of follow-up, ten of 16 long-term carriers and the two household contacts were MRSA-negative. In conclusion, decolonization of MRSA carriers is possible, but should include treatment of household members and the environment.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Anti-Bacterial Agents; Carrier State; Cats; Child; Child, Preschool; Denmark; Disease Outbreaks; Dogs; Environmental Microbiology; Female; Humans; Longitudinal Studies; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Staphylococcal Infections; Urine; Wounds and Injuries; Young Adult

Methicillin-resistant staphylococci (MRS) were isolated from nasal swabs of 56 of 159 (35.2%; 95% confidence interval [CI]: 27.9-43.2%) healthy horses. Two nasal swabs were collected from each horse; 43 of 159 (27%; 95% CI: 20.5-34.8%) of the cohort were colonized by MRS strains in 1 nostril, while in the remaining 13 of 159 (8.2%; 95% CI: 4.6-13.9%), different or identical MRS strains were isolated in both nostrils. Of the 29 humans in close contact with the horses tested, 4 (13.8%; 95% CI: 4.5-32.6%) were found to be carriers of MRS. All isolates were coagulase negative with the exception of 2 coagulase-positive MRS strains, Staphylococcus aureus and Staphylococcus pseudintermedius, both isolated from horses. To assay the methicillin resistance, a susceptibility test to oxacillin with standardized disk diffusion method, a PBP-2a latex agglutination test, and a methicillin resistance gene (mecA) polymerase chain reaction assay were performed. Pulsed-field gel electrophoresis patterns of isolates from horses and humans in close contact with the horses revealed similarity. The results suggest evidence of transmission between animals, from animals to humans, and vice versa.

Topics: Animals; Carrier State; Female; Horse Diseases; Horses; Humans; Italy; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections

To assess the prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) colonization in HIV-1-infected men who have sex with men (MSM), a cross-sectional study was conducted on 104 persons attending a large STI/HIV unit in Rome, Italy in the period June 2007-June 2008. Swabs obtained from both anterior nares and S. aureus isolates were characterized by phenotypic and genotypic methods. A total of 24 individuals (23.1%) were colonized with S. aureus but none carried MRSA. No statistically significant association between colonization with S. aureus and behavioural, clinical, virological or immunological characteristics was identified. This study indicates a lack of circulation of CA-MRSA in HIV-1-infected MSM in Italy and underscores large epidemiological differences between the USA and a European country, so that only locally conducted epidemiological studies can provide insight into the local circulation of CA-MRSA in general and selected populations.

Topics: Adult; Carrier State; Community-Acquired Infections; Cross-Sectional Studies; HIV Infections; HIV-1; Homosexuality, Male; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Rome; Staphylococcal Infections

The purpose of this study was to identify differences in the sensitivity of anatomical sites sampling for methicillin-resistant Staphylococcus aureus (MRSA) colonization related to age, gender, clinical situation, and acquisition source as a base for screening protocols. We used a database that included all MRSA-positive cultures (Carmel Medical Center, 2003-2006) taken from nares, throat, perineum, and infection sites. The study population of 597 patients was divided into: "screening sample" (SS), which were cases of routine screening, and "clinical diagnostic sample" (CDS), which were patients with concurrent MRSA infection. MRSA acquisition sources were classified as internal medicine, surgical, referral patients, or intensive care unit (ICU). CDS patients were older than SS patients (median age 78 vs. 74 years, p = 0.0002), more commonly throat colonized (47.5% vs. 31.8%, p = 0.0001), and colonized in more multiple sites (65.7% vs. 43.3% were colonized in three sites in the CDS and SS groups, respectively, p < 0.001) than SS patients. In the SS, group throat colonization was higher in internal medicine wards than in the ICU (odds ratio [OR] = 3.98, p < 0.0001). In the CDS group, perineal colonization was more common in referral patients than in the ICU (OR = 4.52, p < 0.05). Patient age was the most influential factor on nares and multiple sites colonization in the SS and CDS groups, respectively. Our data support multiple sites sampling. Throat cultures are crucial in MRSA-infected patients and internal medicine ward patients. Multiple body sites colonization is more likely in older or MRSA-infected patients, affecting decisions regarding eradication using topical antibiotics.

Topics: Aged; Aged, 80 and over; Bacteriological Techniques; Carrier State; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Perineum; Pharynx; Prevalence; Sensitivity and Specificity; Staphylococcal Infections

Livestock-associated MRSA has been found in various animals, livestock farmers and retail meat. This study aimed to determine the prevalence and determinants of nasal MRSA carriage in pig slaughterhouse workers. Three large pig slaughterhouses in The Netherlands were studied in 2008 using human and environmental samples. The overall prevalence of nasal MRSA carriage in employees of pig slaughterhouses was 5.6% (14/249) (95% CI 3.4-9.2) and working with live pigs was the single most important factor for being MRSA positive (OR 38.2, P<0.0001). At the start of the day MRSA was only found in environmental samples from the lairages (10/12), whereas at the end of the day MRSA was found in the lairages (11/12), the dirty (5/12) and clean (3/12) areas and green offal (1/3). The MRSA status of the environmental samples correlated well with the MRSA status of humans working in these sections (r=0.75). In conclusion, a high prevalence of nasal MRSA carriage was found in pig-slaughterhouse workers, and working with live pigs is the most important risk factor. Exact transmission routes from animals to humans remain to be elucidated in order to enable application of targeted preventive measures.

Topics: Abattoirs; Adult; Aged; Animals; Bacterial Typing Techniques; Carrier State; DNA Fingerprinting; Environmental Microbiology; Female; Genotype; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Netherlands; Nose; Prevalence; Staphylococcal Infections; Staphylococcal Protein A; Swine; Young Adult

One thousand adults aged between 18 and 35 years were investigated for nasal colonization with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Each volunteer completed a questionnaire to assess the presence or absence of risk factors for hospital-acquired MRSA (HA-MRSA) carriage. All MRSA isolated were characterized by microbiological and molecular methods. A S. aureus carriage rate of 22% and a MRSA carriage rate of 0.7% were observed. Analysis of the questionnaires revealed 121 individuals with HA-MRSA risk factors. Subsequently two MRSA infections with associated risk factors were excluded from calculation of the true carriage rate and an adjusted rate of 0.57% (5/879) was established. All seven MRSA isolates expressed the genotypic profile ST22-MRSA-IV, were PVL negative, agr type 1, and differed only by their antimicrobial susceptibility patterns. ST22-MRSA-IV (EMRSA-15) has shown worldwide spread in the hospital setting but has not been previously documented in isolation in the community.

Topics: Adolescent; Adult; Bacterial Proteins; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Community-Acquired Infections; DNA Fingerprinting; DNA, Bacterial; Exotoxins; Female; Genotype; Human Experimentation; Humans; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Surveys and Questionnaires; Trans-Activators; Virulence Factors; Young Adult

The aim of this study was to investigate the prevalence and associated risk factors of methicillin-susceptible and methicillin-resistant Staphylocccus aureus (MSSA and MRSA) carriage in care homes, with particular focus on dementia. A point-prevalence survey of 748 residents in 51 care homes in Gloucestershire and Greater Bristol was undertaken. Dementia was assessed by the clock test or abbreviated mini-mental test. Nasal swabs were cultured for S. aureus on selective agar media. Multivariable analysis indicated that dementia was not a significant risk factor for MSSA (16.2%) or MRSA (7.8%); and that residents able to move around the home unassisted were at a lower risk of MRSA (P=0.04). MSSA carriage increased with increasing age (P=0.03) but MRSA carriage decreased with increasing age (P=0.05). Hospitalization in the last 6 months increased the risk of MSSA (P=0.04) and MRSA (P=0.10). We concluded that cross-infection through staff caring for more dependent residents may spread MRSA within care homes and from the recently hospitalized. Control of MSSA and MRSA in care homes requires focused infection control interventions.

Topics: Aged; Aged, 80 and over; Carrier State; Cross Infection; Dementia; Female; Homes for the Aged; Humans; Male; Nose; Nursing Homes; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United Kingdom

Topics: Anti-Bacterial Agents; Carrier State; Health Personnel; Humans; Laboratories; Methicillin; Microbial Sensitivity Tests; Netherlands; Nose; Occupational Exposure; Pharynx; Prevalence; Staphylococcal Infections; Staphylococcus aureus

Screening and isolation are central components of hospital methicillin-resistant Staphylococcus aureus (MRSA) control policies. Their prevention of patient-to-patient spread depends on minimizing undetected and unisolated MRSA-positive patient days. Estimating these MRSA-positive patient days and the reduction in transmission due to isolation presents a major methodological challenge, but is essential for assessing both the value of existing control policies and the potential benefit of new rapid MRSA detection technologies. Recent methodological developments have made it possible to estimate these quantities using routine surveillance data.. Colonization data from admission and weekly nares cultures were collected from eight single-bed adult intensive care units (ICUs) over 17 months. Detected MRSA-positive patients were isolated using single rooms and barrier precautions. Data were analyzed using stochastic transmission models and model fitting was performed within a Bayesian framework using a Markov chain Monte Carlo algorithm, imputing unobserved MRSA carriage events.. Models estimated the mean percent of colonized-patient-days attributed to undetected carriers as 14.1% (95% CI (11.7, 16.5)) averaged across ICUs. The percent of colonized-patient-days attributed to patients awaiting results averaged 7.8% (6.2, 9.2). Overall, the ratio of estimated transmission rates from unisolated MRSA-positive patients and those under barrier precautions was 1.34 (0.45, 3.97), but varied widely across ICUs.. Screening consistently detected >80% of colonized-patient-days. Estimates of the effectiveness of barrier precautions showed considerable uncertainty, but in all units except burns/general surgery and one cardiac surgery ICU, the best estimates were consistent with reductions in transmission associated with barrier precautions.

Topics: Adult; Carrier State; Cross Infection; Disease Transmission, Infectious; Humans; Intensive Care Units; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Isolation; Staphylococcal Infections

Rapid laboratory diagnosis is critical for treating, managing, and preventing methicillin-resistant Staphylococcus aureus (MRSA) infections. We evaluated and compared the potential for MRSA detection of five chromogenic media, Brilliance MRSA agar (Oxoid), ChromID (bioMérieux), MRSASelect (Bio-Rad), CHROMagar (CHROMagar Microbiology), and BBL-CHROMagar (BD Diagnostics). Media were tested with log serial dilutions (10(0) to 10(6) CFU) of pure isolates of MRSA (n = 60), non-MRSA (n = 27), and defined mixtures thereof simulating clinical samples (n = 84). Further evaluations were done on pre-enriched nasal and groin screening swabs (n = 213) from 165 hospitalized patients. Randomized samples were spiral plated on each medium and independently scored by five investigators for characteristic colonies at 24 and 48 h of incubation. Confirmatory testing of up to five putative MRSA colonies recovered from each medium was done. The cumulative average sensitivity with isolates, mixtures, and clinical samples was the highest for Brilliance MRSA agar (97%) and similar for the other four media (>or=92%). The cumulative average specificity was the highest for BBL-CHROMagar (99%), followed by MRSASelect (98%), CHROMagar (97%), ChromID (89%), and Brilliance MRSA agar (86%). All of the media detected MRSA at 10 and 1 CFU, although at these low loads, few MRSA samples harboring SCCmec type III or IV were misinterpreted as non-MRSA by investigators. False-positive results were mainly due to methicillin-resistant S. epidermidis. For an arbitrary MRSA prevalence of 5% and based on patient sample evaluations, the positive predictive values for BBL-CHROMagar and CHROMagar ( approximately 84%) were the highest. The negative predictive values of all of the media were >or=92% for MRSA prevalences ranging from 5% to 30%. In conclusion, BBL-CHROMagar and CHROMagar gave the best overall results for detection of MRSA, irrespective of the sample concentration, investigator, or incubation period.

Topics: Bacteriological Techniques; Culture Media; Diagnostic Errors; Groin; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Predictive Value of Tests; Random Allocation; Sensitivity and Specificity; Staphylococcal Infections

The objective of the study was to determine if a clonal complex (CC) of Staphylococcus aureus or certain virulence and adhesion factors were associated with infections of bones and prosthetic implants. One hundred and nineteen isolates were characterised using microarrays. There was no evidence for a single virulence factor or CC being causative for bone and implant infections. Isolates belonged to 20 different CCs, with CC8 (19.33%), CC45 (17.65%) and CC30 (12.61%) being dominant. Population structure and the relative abundances of virulence genes was similar to previously described isolates from healthy carriers. Differences to carrier isolates included a higher proportion of CC45, a lower proportion of CC15, as well as a higher abundance of sak (staphylokinase) among patient isolates. For 23 patients with infections of total knee or hip prosthetics, it was possible to simultaneously obtain nasal swabs. Fifteen (65.2%) carried S. aureus in their anterior nares. In nine of them (39.1%), isolates from the infection site were identical to carriage isolates. This suggests an elevated risk of infection for S. aureus carriers and the possibility of endogenous infection in a high proportion of them. Therefore, the pre-operative screening and eradication of S. aureus in patients receiving total joint prosthetics should be considered.

Topics: Bacterial Typing Techniques; Carrier State; DNA Fingerprinting; DNA, Bacterial; Genotype; Humans; Microarray Analysis; Molecular Epidemiology; Nose; Osteoarthritis; Prosthesis-Related Infections; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

As the prompt detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers upon admission is fundamental in the MRSA prevention strategy of our hospital, the infection control team is eagerly seeking the most sensitive and rapid screening method. The aim of this study was to compare the performance of two molecular techniques with a conventional MRSA-selective culture test (Bio-Rad chromogenic MRSASelect) in order to elucidate the suitability of the assays specifically in an expected low MRSA prevalence population.. The anterior nares and throat of 500 patients and visitors attending the emergency department of Sint-Jan General Hospital between May and June 2007 were sampled, and MRSA carriage was determined by selective culture after enrichment and the BD GeneOhm StaphSR and the Cepheid Xpert MRSA assays.. Eight MRSA carriers were detected by selective culture (1.6% prevalence). The sensitivity, specificity, positive [corrected] predictive value, and negative [corrected] predictive value were 62.5, 99.0, 50.0, and 99.4% for BD GeneOhm StaphSR and 62.5, 97.7, 31.3, and 99.4% for Cepheid Xpert MRSA, respectively.. We conclude that MRSA rapid screening techniques must be interpreted cautiously in a low-prevalence population, as the sensitivity is lower than in selected high-risk populations. MRSA carriers detected with molecular techniques must be confirmed by conventional culture methods for follow-up. The specificity and negative predictive value indicate that molecular rapid methods are worthwhile to be considered in MRSA-preventive strategies.

Topics: Bacteriological Techniques; Carrier State; Diagnostic Tests, Routine; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Pharynx; Predictive Value of Tests; Prevalence; Sensitivity and Specificity; Staphylococcal Infections

Our case-control study sought to identify risk factors for colonization with methicillin-resistant Staphylococcus aureus (MRSA) at hospital admission among patients with no known healthcare-related risk factors. We found that patients whose most recent hospitalization occurred greater than 1 year before their current hospital admission were more likely to have MRSA colonization. In addition, both the time that elapsed since the most recent hospitalization and the duration of that hospitalization affected risk.

Topics: Anti-Bacterial Agents; Carrier State; Case-Control Studies; Georgia; Hospitalization; Hospitals, Veterans; Humans; Length of Stay; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Population Surveillance; Prevalence; Risk Factors; Staphylococcal Infections; Time Factors

Healthy carriers of Staphylococcus aureus strains have an important role in the dissemination of this bacterium. To investigate the presence of S. aureus in the throat and anterior nares, samples from 1,243 healthy volunteers in a Mexican community were examined. The percentage of healthy carriers was 59.8%. Results showed that colonization of the throat occurred more frequently than that of the nares (46.5% versus 37.1%, P<0.0001). Of the S. aureus carriers, 22.2% were exclusive nasal carriers and 38% were exclusive throat carriers. A total of 1,039 strains were isolated; 12.6% were shown to be methicillin-resistant S. aureus (MRSA). Of MRSA strains, 32.1% were isolated from exclusive throat carriers. Most of the strains isolated from the anterior nares and throat of the same carriers were the same or related; however, some were different. Pulsed-field gel electrophoresis (PFGE) pattern analysis of the MRSA strains isolated from the exclusive nasal carriers or exclusive throat carriers showed that they belong to different clusters. A 6-year prospective study was performed to investigate the persistence of S. aureus in the throat. Results showed that 13% of subjects were persistent carriers. Most of them were colonized with the same clone of S. aureus throughout the time of the study, and just three had different clones. Antimicrobial susceptibility testing showed that 91.1% of the strains were penicillin resistant. The presence of mecA and nucA genes (in order to confirm methicillin resistance) and of thermostable nuclease of S. aureus was examined. This study showed that some strains of S. aureus regularly colonized the throats of healthy people and could persist for years.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cluster Analysis; DNA Fingerprinting; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Humans; Infant; Male; Methicillin Resistance; Mexico; Middle Aged; Nose; Penicillin Resistance; Pharynx; Polymerase Chain Reaction; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors; Young Adult

We evaluated our experience in a low prevalence setting to determine the extent to which multiple swabs increased detection rates and the incremental costs of doing so.. Nasal and groin swabs submitted in pairs were cultured onto a single plate (Oxoid MRSA Denim Blue Agar; Oxoid Company, Napean, ON, Canada). We determined whether MRSA was detected when swabs submitted in the preceding 3 days were negative. We explored the costs associated with screening and of each additional colonized patient detected.. In all, 60,049 paired nose and perineal swabs were submitted from 21,599 patients. In all, there were 12,750 duplicate, 1437 triplicate, and 112 instances when >4 swabs were processed within 3 days. The first culture was positive in 106 of 12,750 (0.83%%), 42 of 12,750 (0.33%) on the second when the first was negative, 7 of 1642 (0.43%) on the third or subsequent swab pair when the preceding 2 were negative.. Overall, the sensitivity of the first of multiple cultures of a set was 74.3%. Had the 14,392 multiple samples not been submitted, 49 colonized patients would not have been identified. Additional laboratory costs associated with multiple samples equaled $2088 per patient identified.

Topics: Bacteriological Techniques; Canada; Colony Count, Microbial; Costs and Cost Analysis; Groin; Humans; Infection Control; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Population Surveillance; Staphylococcal Infections

The nasopharynx is the main ecological niche of the human pathogen Staphylococcus aureus. Although colonization of the nares is asymptomatic, nasal carriage is a known risk factor for endogenous staphylococcal infection. We quantified S. aureus mRNA levels in nose swabs of persistent carriers to gain insight into the regulatory adaptation of the bacterium to the nasal environment. We could elucidate a general response of the pathogen to the surrounding milieu independent of the strain background or the human host. Colonizing bacteria preferentially express molecules necessary for tissue adherence or immune-evasion whereas toxins are down regulated. From the analysis of regulatory loci we found evidence for a predominate role of the essential two-component system WalKR of S. aureus. The results suggest that during persistent colonization the bacteria are metabolically active with a high cell surface turnover. The increased understanding of bacterial factors that maintain the colonization state can open new therapeutic options to control nasal carriage and subsequent infections.

Topics: Adhesins, Bacterial; Bacterial Toxins; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Gene Regulatory Networks; Humans; Immune Evasion; Metabolism; Nose; RNA, Bacterial; Staphylococcal Infections; Staphylococcus aureus

A total of 2,662 samples, collected from March to September 2009 in Switzerland, were tested for the presence of meticillin-resistant Staphylococcus aureus (MRSA). The collection comprised nasal swabs from 148 pig farmers, 133 veterinarians, 179 slaughterhouse employees, 800 pigs, 300 calves, 400 cattle, 100 pooled neck skin swabs from chicken carcasses, and 460 food samples of animal origin. Moreover, 142 S. aureus strains, isolated from bovine mastitis milk, were included in the study. Twenty samples (< 1%; four veterinarians, 10 pigs, three calves, one young bull, and two mastitis milk samples) tested positive for MRSA. Genotyping of the MRSA strains was performed by multilocus sequence typing, spa- and SCCmec-typing, and revealed ST398 (n=18), ST8 (n=1), ST 1 (n=1), spa types t011 (n=7), t034 (n=11), t064 (n=1), t127 (n=1), and SCCmec types IV (n=4) and V (n=16). The 20 MRSA strains were subjected to antibiotic susceptibility testing and pulsed-field gel electrophoresis using the restriction enzyme EagI. Supplementary PCR reactions were performed to investigate the presence of Panton-Valentine leukocidin and staphylococcal enterotoxins A to D.

Topics: Agriculture; Animals; Carrier State; Case-Control Studies; Cattle; Cattle Diseases; Chickens; Female; Food Contamination; Food Microbiology; Humans; Mastitis, Bovine; Meat; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Milk; Nose; Population Surveillance; Poultry Diseases; Prevalence; Risk Assessment; Risk Factors; Species Specificity; Staphylococcal Food Poisoning; Staphylococcal Infections; Swine; Swine Diseases; Switzerland; Veterinarians

Comparison of flocked swabs (E-swabs; Copan) to the standard rayon swabs (Copan) was undertaken for detection of Staphylococcus aureus nasal carriage among staff at Dorevitch Pathology in Heidelberg, Melbourne, Australia. Among 100 volunteers, 36 were found to be colonized with S. aureus by one or both swab results. The prevalence detected by E-swabs was 35%, and the prevalence through rayon swabs was 34% (95% confidence interval [CI] for the difference in proportions, -12 to 14). Thirty-three volunteers tested positive with both types of swabs, while 2 were detected on E-swabs alone and another on rayon swab testing alone. There was no evidence of a significant difference in carriage detected by E-swabs or rayon swabs.

Topics: Australia; Bacteriological Techniques; Carrier State; Cellulose; Health Personnel; Human Experimentation; Humans; Nose; Prevalence; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

Rapid and reliable detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers is crucial for control of MRSA nosocomial transmission. We aimed to evaluate the performance of the GeneXpert real-time PCR system using the Xpert MRSA assay on a collection of 40 representative Belgian MRSA strains and for MRSA screening of geriatric inpatients. Double nasal swabs were used: the first swab for the Xpert MRSA assay and the second for culture onto chromogenic selective medium and enrichment broth. All but 1 of the 40 collection strains were recognized as MRSA by the Xpert MRSA assay. Nares swabs were prospectively collected from 246 inpatients including 25 nasal MRSA carriers. Compared with enriched cultures, the sensitivity, the specificity, and the positive and negative predictive values of the Xpert MRSA assay were 69.2%, 97.7%, 78.3%, and 96.3% respectively. The 7 evaluable false-negative results according to the assay were due to its possible lack of sensitivity (n = 3) and to the occurrence of a Belgian MRSA clone carrying a particular staphylococcal chromosomal cassette mec (SCCmec) type IV variant (n = 4) not targeted by the current Xpert MRSA assay. Because of the evolution of SCCmec in MRSA, new primers should be designed and further studies are warranted to ensure continuous monitoring of this assay.

Topics: Bacterial Proteins; Bacterial Typing Techniques; Bacteriological Techniques; Carrier State; Cluster Analysis; DNA Fingerprinting; DNA, Bacterial; Genotype; Health Services for the Aged; Hospitals; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Sensitivity and Specificity; Staphylococcal Infections

Recently, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) have been increasingly isolated from veterinarians and companion animals. With a view to preventing the spread of MRSA and MRSP, we evaluated the occurrence and molecular characteristics of each in a veterinary college. MRSA and MRSP were isolated from nasal samples from veterinarians, staff members, and veterinary students affiliated with a veterinary hospital. Using stepwise logistic regression, we identified two factors associated with MRSA carriage: (i) contact with an identified animal MRSA case (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 2.2 to 21.6) and (ii) being an employee (OR, 6.2; 95% CI, 2.0 to 19.4). The majority of MRSA isolates obtained from individuals affiliated with the veterinary hospital and dog patients harbored spa type t002 and a type II staphylococcal cassette chromosome mec (SCCmec), similar to the hospital-acquired MRSA isolates in Japan. MRSA isolates harboring spa type t008 and a type IV SCCmec were obtained from one veterinarian on three different sampling occasions and also from dog patients. MRSA carriers can also be a source of MRSA infection in animals. The majority of MRSP isolates (85.2%) carried hybrid SCCmec type II-III, and almost all the remaining MRSP isolates (11.1%) carried SCCmec type V. MRSA and MRSP were also isolated from environmental samples collected from the veterinary hospital (5.1% and 6.4%, respectively). The application of certain disinfection procedures is important for the prevention of nosocomial infection, and MRSA and MRSP infection control strategies should be adopted in veterinary medical practice.

Topics: Animals; Bacterial Typing Techniques; Carrier State; Disease Transmission, Infectious; DNA Fingerprinting; DNA, Bacterial; Dogs; Environmental Microbiology; Hospitals, Animal; Humans; Infection Control; Japan; Methicillin Resistance; Molecular Epidemiology; Nose; Staphylococcal Infections; Staphylococcus; Students; Veterinarians

Data on community spread of methicillin-resistant coagulase-negative staphylococci (MR-CoNS) are scarce. We assessed their potential role as a reservoir of staphylococcal cassette chromosome mec (SCCmec) IVa, the leading SCCmec subtype in community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).. Nasal carriage of MR-CoNS was prospectively investigated in 291 adults at hospital admission. MR-CoNS were characterized by SCCmec typing, long-range polymerase chain reaction (PCR) for SCCmec IV, and multiple-locus variable-number tandem repeat analysis (MLVA) for Staphylococcus epidermidis (MRSE) strains. Three SCCmec IVa elements were fully sequenced.. The carriage rate of MR-CoNS was 19.2% (25.9% and 16.5% in patients with and patients without previous exposure to the health care system, respectively; P = .09). MR-CoNS strains (n = 83, including 58 MRSE strains with highly heterogeneous MLVA patterns) carried SCCmec type IVa (n = 9, all MRSE), other SCCmec IV subtypes (n = 9, including 7 MRSE), other SCCmec types (n = 15), and nontypeable SCCmec (n = 50). Long-range PCR indicated structural homology between SCCmec IV in MRSE and that in MRSA. Complete sequences of SCCmec IVa from 3 MRSE strains were highly homologous to those available for CA-MRSA, including major clones USA300 and USA400.. MR-CoNS are probably disseminated in the community, notably in subjects without previous exposure to the health care system. MRSE, the most prevalent species, may act as a reservoir of SCCmec IVa for CA-MRSA.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Base Sequence; Clone Cells; Coagulase; Disease Reservoirs; DNA Primers; Drug Resistance, Bacterial; Female; Hospitalization; Humans; Immunoglobulin Allotypes; Male; Methicillin Resistance; Middle Aged; Nose; Polymerase Chain Reaction; Renal Dialysis; Staphylococcal Infections; Staphylococcus epidermidis

Most Staphylococcus aureus small-colony variants (SCVs) are auxotrophs for menadione, hemin, or thymidine but rarely for CO(2). We conducted a prospective investigation of all clinical cases of CO(2)-dependent S. aureus during a 3-year period. We found 14 CO(2)-dependent isolates of S. aureus from 14 patients that fulfilled all requirements to be considered SCVs, 9 of which were methicillin resistant. The clinical presentations included four cases of catheter-related bacteremia, one complicated by endocarditis; two deep infections (mediastinitis and spondylodiscitis); four wound infections; two respiratory infections; and two cases of nasal colonization. Pulsed-field gel electrophoresis typing showed that the 14 isolates were distributed into 4 types corresponding to sequence types ST125-agr group II (agrII), ST30-agrIII, ST34-agrIII, and ST45-agrI. An array hybridization technique performed on the 14 CO(2)-dependent isolates and 20 S. aureus isolates with normal phenotype and representing the same sequence types showed that all possessed the enterotoxin gene cluster egc, as well as the genes for alpha-hemolysin and delta-hemolysin; biofilm genes icaA, icaC, and icaD; several microbial surface components recognizing adhesive matrix molecules (MSCRAMM) genes (clfA, clfB, ebh, eno, fib, ebpS, sdrC, and vw); and the isaB gene. Our study confirms the importance of CO(2)-dependent SCVs of S. aureus as significant pathogens. Clinical microbiologists should be aware of this kind of auxotrophy because recovery and identification are challenging and not routine. Further studies are necessary to determine the incidence of CO(2) auxotrophs of S. aureus, the factors that select these strains in the host, and the genetic basis of this type of auxotrophy.

Topics: Aged; Bacteremia; Bacterial Typing Techniques; Carbon Dioxide; Carrier State; Catheter-Related Infections; Discitis; DNA Fingerprinting; Electrophoresis, Gel, Pulsed-Field; Endocarditis, Bacterial; Genotype; Humans; Male; Mediastinitis; Microarray Analysis; Middle Aged; Nose; Respiratory Tract Infections; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors; Wound Infection

Review the literature on methicillin-resistant Staphylococcus aureus (MRSA) infection following septorhinoplasty, identify patient groups at risk for MRSA complications following septorhinoplasty, and evaluate the need for antibiotic prophylaxis in these patients.. Patients who are susceptible to MRSA infections may also be at higher risk for nasal colonization, and this includes elderly patients, patients recently hospitalized or treated in a rehabilitation center, and healthcare workers. Few cases of MRSA infection following septorhinoplasty have been reported in the literature. Prevention of nosocomial and postsurgical MRSA infections has been well studied, and it seems that elimination of nasal colonization is a major step in preventing these infections.. Patients at increased risk for MRSA colonization should be screened prior to septorhinoplasty and if positive treated with antibiotic prophylaxis consisting of elimination of nasal carriage prior to surgery. Perioperative systemic antibiotic use should be considered, especially in revision cases.

Topics: Antibiotic Prophylaxis; Humans; Methicillin-Resistant Staphylococcus aureus; Nasal Septum; Nose; Postoperative Complications; Rhinoplasty; Staphylococcal Infections

Sensitive detection of Staphylococcus aureus colonization is important for epidemiologic studies, infection control, and decolonization measures. We examined the sensitivity of nasal and pharyngeal sampling for S. aureus colonization in 331 children admitted to intensive care units. Pharyngeal screening was more sensitive than nasal screening (92.6% versus 63.1%, P < 0.0001).

Topics: Adolescent; Bacteriological Techniques; Carrier State; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Intensive Care Units, Pediatric; Nose; Pharynx; Prevalence; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

To determine the frequency and clinical importance of methicillin-resistant Staphylococcus aureus (MRSA) colonization in student athletes.. Prospective observational cohort study.. A major university in the southeastern United States.. Student athletes participating in the men's football and women's lacrosse programs (N = 126). Main Exposure Monthly assessment of S aureus nasal colonization.. Trends in S aureus colonization over time and the occurrence of skin and soft tissue infections.. Methicillin-resistant S aureus nasal colonization varied significantly through the athletic season (4%-23%), peaking during times of highest athletic activity. This increase in colonization was not associated with the development of an outbreak of skin and soft tissue infections, and no single MRSA clone emerged as a dominant isolate.. During the athletic season, there is a considerable burden of MRSA colonization in student athletes; however, colonization alone appears to be insufficient to trigger an outbreak of staphylococcal infections. A combination of distinct molecular characteristics in the organism and specific host factors may govern the development of staphylococcal disease.

Topics: Adolescent; Adult; Athletes; Female; Football; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Nose; Prospidium; Racquet Sports; Sports; Staphylococcal Infections; Staphylococcal Skin Infections

Staphylococcus aureus is currently the most common cause of infection in hospitalized patients. Patients on hemodialysis are at increased risk due to their immunocompromised state. The present study was designed to determine the frequency of S aureus nasal carriage in patients on hemodialysis.. This study was undertaken in 2 dialysis centers to establish the frequency of S aureus nasal carriage at teaching hospitals of Mazandaran University of Medical Sciences, in the north of Iran. Standardized nose swabs were rotated into the anterior nares of the patients, and the samples were cultured on a blood-agar medium. Having grown the colony, gram stain, catalase, manitol, DNAase, and coagulase tests were all performed. Pattern of antibacterial sensitivity was determined by using the disc diffusion method. Also, agar dilution method was used to determine minimal inhibitory concentration of oxacillin and vancomycin.. Of 84 patients on hemodialysis, 31 (36.9%) were nasal carriers of S aureus, of whom 23 (74.2%) were resistant to methicillin. Of the methicillin-resistant S aureus isolates, 3 (13.0%) were resistant to vancomycin and 7 (56.5%) had reduced susceptibility to vancomycin in agar dilution method. Resistance frequencies to clindamycin, ciprofloxacin, and trimethoprim-sulfamethoxsazole were 12.9%, 9.7%, and 19.3%, respectively. However, all microorganisms were sensitive to rifampicin.. Patients on hemodialysis are at an increased risk of S aureus infections; thus, screening of these susceptible patients should be considered as a health priority. Meanwhile, microbial sensitivity tests should be ordered for all cases in order to optimize treatment options.

Topics: Anti-Bacterial Agents; Carrier State; Chi-Square Distribution; Drug Resistance, Bacterial; Female; Humans; Immunocompromised Host; Iran; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Topics: Carrier State; Fingers; Health Facilities; Health Personnel; Humans; Libya; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Prevalence; Staphylococcal Infections

Topics: Administration, Intranasal; Administration, Topical; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Comparative Effectiveness Research; Humans; Methicillin-Resistant Staphylococcus aureus; Mohs Surgery; Mupirocin; Nose; Prospective Studies; Research Design; Retrospective Studies; Staphylococcal Infections; Surgical Wound Infection

Menstrual Toxic Shock Syndrome (mTSS) is thought to be associated with the vaginal colonization with specific strains of Staphylococcus aureus TSST-1 in women who lack sufficient antibody titers to this toxin. There are no published studies that examine the seroconversion in women with various colonization patterns of this organism. Thus, the aim of this study was to evaluate the persistence of Staphylococcus aureus colonization at three body sites (vagina, nares, and anus) and serum antibody to toxic shock syndrome toxin-producing Staphylococcus aureus among a small group of healthy, menstruating women evaluated previously in a larger study.. One year after the completion of that study, 311 subjects were recalled into 5 groups. Four samples were obtained from each participant at several visits over an additional 6-11 month period: 1) an anterior nares swab; 2) an anal swab; 3) a vagina swab; and 4) a blood sample. Gram stain, a catalase test, and a rapid S. aureus-specific latex agglutination test were performed to phenotypically identify S. aureus from sample swabs. A competitive ELISA was used to quantify TSST-1 production. Human TSST-1 IgG antibodies were determined from the blood samples using a sandwich ELISA method.. We found only 41% of toxigenic S. aureus and 35.5% of non-toxigenic nasal carriage could be classified as persistent. None of the toxigenic S. aureus vaginal or anal carriage could be classified as persistent. Despite the low persistence of S. aureus colonization, subjects colonized with a toxigenic strain were found to display distributions of antibody titers skewed toward higher titers than other subjects. Seven percent (5/75) of subjects became seropositive during recall, but none experienced toxic shock syndrome-like symptoms.. Nasal carriage of S. aureus appears to be persistent and the best predicator of subsequent colonization, whereas vaginal and anal carriage appear to be more transient. From these findings, it appears that antibody titers in women found to be colonized with toxigenic S. aureus remained skewed toward higher titers whether or not the colonies were found to be persistent or transient in nature. This suggests that colonization at some point in time is sufficient to elevate antibody titer levels and those levels appear to be persistent. Results also indicate that women can become seropositive without experiencing signs or symptoms of toxic shock syndrome.

Topics: Adult; Anal Canal; Antibodies, Bacterial; Antitoxins; Bacterial Toxins; Carrier State; Enterotoxins; Enzyme-Linked Immunosorbent Assay; Female; Humans; Menstruation; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Superantigens; Time Factors; Vagina

Infections with methicillin-resistant Staphylococcus aureus (MRSA), in community-settings, especially with strains carrying the Panton-Valentine Leukocidin (PVL) genes, have increased markedly in recent years. Colonization with S. aureus is a risk factor for infection. However, there are few studies that examine colonization and infection with PVL-positive strains of MRSA in cancer patients.. The epidemiology of colonization and infection with MRSA was studied in children with cancer during two time periods: 2000/2001 and 2006/2007. PVL genes were screened and spa typing performed on the isolates.. The prevalence of colonization with MRSA increased from 0.6% in 2000/2001 to 2.9% in 2006/2007 (P = 0.0003). MRSA colonization at admission was associated with infection (P < 0.0001; RR 38.32; 95% CI: 23.36-62.84). The prevalence of infection increased from 0.99% in 2000/2001 to 3.78% in 2006-2007 (P = 0.0002). Of the 32 colonized patients, 18 (56%) had infection. None of the 14 colonized but non-infected patients had dual colonization of nares and rectum, while 8 of the 18 infected patients had colonization of both of these sites (P = 0.004). Ten patients (31%) were colonized with PVL-positive strains. Patients colonized with PVL-positive strains were more likely to be colonized both in the nares and rectum (P = 0.005), and more likely to have infection (P = 0.001). Recurrent MRSA infections were seen in 22% of patients.. An increasing prevalence of colonization with MRSA was observed in children with cancer at our institution. Colonization with MRSA especially with PVL-positive strains was associated with infection.

Topics: Bacterial Toxins; Child; Exotoxins; Female; Humans; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Neoplasms; Nose; Rectum; Staphylococcal Infections

Universal surveillance upon patient admission is important in reducing the transmission of methicillin-resistant Staphylococcus aureus (MRSA) and associated disease in hospitals. High costs for the health care system in conjunction with MRSA have promoted the development of rapid screening methods to detect MRSA carriers. This study compared two real-time PCR methods, the BD GeneOhm MRSA assay (BDGO) and the Xpert MRSA assay, with broth-enriched culture to define their performance characteristics and rapidity in an area with low MRSA prevalence. In total, 414 swabs from the nose and 389 swabs from the groin from 425 patients were tested. Of those 425 patients, 378 had swabs from both the nose and groin in parallel. Two hundred thirty-one and 194 patients were randomly assigned to the BDGO group and the Xpert MRSA group, respectively. In general, sensitivity, specificity, and negative predictive value (NPV) were high for the BDGO (100%, 98.5%, and 100%, respectively) and the Xpert MRSA (100%, 98.2%, and 100%, respectively), irrespective of whether or not nasal and inguinal specimens were considered alone or combined. In contrast, the positive predictive value (PPV) was lower: before the resolution of discrepant results, the PPVs for nasal and inguinal specimens alone and combined were 87.5%, 86.7%, and 82.4% for the BDGO and 91.7%, 66.7%, and 92.9% for the Xpert MRSA, respectively. After the resolution of discrepant results, PPVs were 93.8%, 93.3% and 94.1% for the BDGO and 91.7%, 88.9% and 92.9% for the Xpert MRSA, respectively. With the BDGO, 4 of 16 carriers were each identified by nasal or inguinal swabs alone, whereas in the Xpert MRSA group, 4 of 13 carriers were exclusively identified by nasal swabs and 2 of 13 were identified by inguinal swabs alone. Both PCR methods showed no significant difference in the number of discrepant results (odds ratio, 0.70 [P = 0.789]), but specimens from wounds and other body sites (axilla, vagina, and throat) produced discrepancies more often than nasal and groin specimens (odds ratios, 4.724 [P = 0.058] and 12.163 [P < 0.001], respectively). The facts that no false-negative PCR results were detected and increased PPVs were found after the resolution of discrepant results point to PCR as the actual gold standard. Since both sensitivity and NPV were exceptionally high for PCR, backup cultures may, therefore, be unnecessary in an area with low prevalence and with a preemptive isolation strategy but may still be useful

Topics: Bacteriological Techniques; Groin; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Prevalence; Reagent Kits, Diagnostic; Sensitivity and Specificity; Staphylococcal Infections

Staphylococcus aureus is the major cause of surgical site infections, and meticillin-resistant S. aureus (MRSA) is increasingly accounting for infections worldwide. Preventing surgical site infections by screening and decolonising positive patients reduces the number of infections, but does not completely eradicate the risk. A balance between prevention, costs and the chance of mupirocin-resistant S. aureus needs to be evaluated and decolonisation strategies optimised. It is essential to know the site of S. aureus during colonisation. In this study, for the first time the exact location of S. aureus in the human nose was determined using a histological approach. We showed the presence of S. aureus in the cornified layer of squamous epithelium, associated keratin and mucous debris and within hair follicles in the vestibulum nasi. The presence of S. aureus in hair follicles suggests that this could be the niche from which relapses occur after decolonisation. Decolonisation strategies might have to be reconsidered.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Epithelium; Female; Hair Follicle; Humans; Immunohistochemistry; Male; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

The incidence of and risk factors for acquiring community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) among patients staying in intensive care units (ICUs) remain unclear. We enrolled patients staying in two ICUs at the Far Eastern Memorial Hospital during the period of 1 September 2008 to 30 September 2009 to clarify this issue. Surveillance cultures for MRSA were taken from nostril, sputum or throat, axillae, and the inguinal area in all enrolled patients upon admission to the ICU, every 3 days thereafter, and on the day of discharge from the ICU. For each MRSA isolate, we performed multilocus sequence typing, identified the type of staphylococcal cassette chromosome mec, detected the presence of the Panton-Valentine leukocidin gene, and conducted drug susceptibility tests. Among the 1,906 patients who were screened, 203 patients were carriers of MRSA before their admission to the ICU; 81 patients acquired MRSA during their stay in the ICU, including 31 who acquired CA-MRSA. The incidence rates of newly acquired MRSA and CA-MRSA during the ICU stay were 7.9 and 3.0 per 1,000 patient-days, respectively. Prior usage of antipseudomonal penicillins and antifungals and the presence of a nasogastric tube were found to be independent risk factors for acquiring CA-MRSA during the ICU stay when data for CA-MRSA carriers and patients without carriage of MRSA were compared (P=0.0035, 0.0330, and 0.0262, respectively). Prior usage of carbapenems was found to be a protective factor against acquiring CA-MRSA when data for patients with CA-MRSA and those with health care-associated MRSA acquired during ICU stay were compared (P=0.0240).

Topics: Abdomen; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Axilla; Bacterial Toxins; Carrier State; Community-Acquired Infections; Cross Infection; Exotoxins; Female; Humans; Incidence; Intensive Care Units; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Multilocus Sequence Typing; Nose; Pharynx; Risk Factors; Sputum; Staphylococcal Infections; Young Adult

Recognition of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage by active surveillance cultures has been widely debated. Our institution implemented universal nasal screening by polymerase chain reaction (PCR) for MRSA and isolation of screen positive patients in December 2007. Here we present data about the correlation between screen positivity and subsequent development of infection and the impact of isolation on surgical site infection rates.. This was a retrospective, observational study from January 1, 2008, through June 30, 2008, on all inpatient admissions with a nasal MRSA PCR screen. Genotype of 15 MRSA blood isolates was determined utilizing the Diversilab® (bioMérieux, Hazelwood, MO) system. A phenotypic rule was deduced and utilized for analyzing all MRSA clinical isolates.. 5375 patients were screened at ≤48 hours following admission. 581 MRSA positive nasal carriers (10.80%) were identified. 496 (85.3%) were asymptomatic MRSA nasal carriers. There were a total of 158 MRSA clinical infections. 85 (14.6%) MRSA nasal carriers had clinical infection. Of the 4794 (89.1%) non-nasally colonized patients, 73 (1.5%) had MRSA clinical infection. MRSA surgical site infection rate remained unchanged during the intervention period. Phenotypic predictive rule inferred 59.8% community-acquired MRSA (CA-MRSA) infections and 40% hospital-acquired MRSA (HA-MRSA) infections.. Our study showed a positive correlation between having a nasal screen positivity and subsequent development of infection. Isolation of MRSA screen positive patients alone as an intervention did not reduce the surgical site infection rates. Since most of our isolates are CA-MRSA, our institution is implementing several new interventions to further reduce the incidence of HA-MRSA conditions.

Topics: Carrier State; Cost-Benefit Analysis; Cross Infection; Female; Humans; Male; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Outcome Assessment, Health Care; Polymerase Chain Reaction; Population Surveillance; Retrospective Studies; Staphylococcal Infections; Surgical Wound Infection; Texas

A rapid diagnostic method for methicillin-resistant Staphylococcus aureus (MRSA) has been implemented for surveillance of the at-risk population, but its performance in those without traditional risk factors is not clear. The objective of this study was to evaluate MRSA colonization status by comparing the performance of the BD GeneOhm MRSA polymerase chain reaction (PCR) assay with that of conventional culture during a 3-month active surveillance of Taiwanese adults in the community.. From 1 October 2007 to 28 December 2007, adults (≥ 18 years old) attending a mandatory health examination arranged by their employers as a part of the workplace health promotion program at three medical centers in northern Taiwan were enrolled in the study. No healthcare workers were included. A total of 498 paired nasal swabs were prospectively obtained and used for both the BD GeneOhm MRSA PCR assay and conventional culture.. Of the 498 paired nasal swabs, 14 (2.8%) were positive for MRSA by conventional culture and 34 (6.8%) were positive by the BD GeneOhm MRSA PCR assay (p < 0.005). Thirteen specimens were both culture- and PCR-positive, and 463 samples were both culture- and PCR-negative. There were two discordant results: 21 specimens were culture-negative/PCR-positive, and one was culture-positive/PCR-negative. The simple kappa coefficient for measuring the agreement between conventional culture and the MRSA PCR assay was 0.52.. This study demonstrates the feasibility of using both the MRSA PCR assay and conventional culture as surveillance tools. Also, the MRSA-positive rate detected by MRSA PCR assay was significantly higher than that of conventional culture.

Topics: Adult; Bacteriological Techniques; Carrier State; Community-Acquired Infections; Culture Media; Diagnostic Techniques and Procedures; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Sensitivity and Specificity; Sentinel Surveillance; Staphylococcal Infections; Taiwan; Young Adult

The extent to which GPs serve as a reservoir for antibiotic-resistant Staphylococcus aureus is unknown and not well studied.. To determine the prevalence of nasal S. aureus carriage among GPs in the Netherlands, as well as the antimicrobial resistance and the genotypes of isolated S. aureus.. Observational, point-prevalence, and cross-sectional study.. GPs attending the annual conference of the Dutch College of General Practitioners in 2006.. Nasal swabs were randomly taken from 395 GPs and analysed for the presence of S. aureus. Antimicrobial susceptibility was determined by a microbroth dilution method and the genotypes by spa typing, which was associated with multilocus sequence typing.. Of the GPs, 129/395 (33%; 95% confidence interval [CI] = 28 to 37%) were carriers of S. aureus. No meticillin-resistant S. aureus (MRSA) was found. Resistance was observed to penicillin (71%; 95% CI = 63 to 79%), fusidic acid (7%; 95% CI = 3 to 13%), and clarithromycin (6%; 95% CI = 3 to 12%). In 72% of the isolates, an MRSA-related genotype of S. aureus was found.. The low antibiotic resistance found among S. aureus of GPs suggests that GPs are not a reservoir of antibiotic-resistant S. aureus strains. The relatively high resistance to fusidic acid, which has not previously been described in the Netherlands and is mostly because of antibiotic use, suggests that patients infect GPs and not the other way round. GPs may be at risk for nasal carriage of S. aureus with an MRSA-related genotype.

Topics: Carrier State; Drug Resistance, Microbial; Epidemiologic Methods; Fusidic Acid; General Practitioners; Humans; Microbial Sensitivity Tests; Netherlands; Nose; Staphylococcal Infections; Staphylococcus aureus

In the Netherlands, meticillin-resistant Staphylococcus aureus (MRSA) is detected on pork and veal farms, and hence farmers working with MRSA-positive animals are at an increased risk of being colonised. Recently retail meat products have been found positive for MRSA. Therefore, we tested the prevalence of MRSA among employees who work in the cold meat processing industry and in institutional kitchens. Nasal swabs and samples from the employees' hands as well as the handled meat were tested quantitatively and qualitatively for the presence of MRSA. Typical colonies were confirmed by PCR and typed using multi-locus sequence typing and spa–typing. All samples taken from 95 employees tested negative for MRSA, but 31 carried MSSA. From meat, five of 35 samples were positive for MRSA, containing between 0.01 and more than 10 bacteria per gram. The risk for professionals of MRSA colonisation from handling raw meat was therefore low in our setting, suggesting that the general population is at an even lower risk of being infected through meat handling.

Topics: Animals; Bacterial Typing Techniques; Female; Food Contamination; Food Handling; Food Microbiology; Humans; Male; Meat; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Netherlands; Nose; Occupational Exposure; Phenotype; Polymerase Chain Reaction; Prevalence; Risk Factors; Staphylococcal Infections; Swine

There is increasing evidence that community acquired S. aureus infections are spreading among healthy children. Nasal colonization with S. aureus plays pivotal role in the increasing prevalence of resistant community acquired S. aureus infections worldwide. A regular surveillance system is important in ensuring quality of patient care. The aim of the study was to assess the prevalence of and the factors associated with nasal carriage of S. aureus and its antibiotic sensitivity pattern among healthy children in Ujjain, India.. A prospective study was done in paediatric outpatient clinics of R.D. Gardi medical college Ujjain, India. Healthy children from 1 month to 59 months of age were included. Information on previously known risk factors for nasal colonization was collected using a pre-tested questionnaire. Swabs from anterior nares were collected and transported in Amies transport media with charcoal and cultured on 5% sheep blood agar. Antibiotic sensitivity tests were performed using Kirby Bauer's disc diffusion method according to performance standards of Clinical and Laboratory Standard Institute guidelines.. Of the 1,562 children from 1-month up-to five years of age included in the study 98 children tested positive for nasal carriage of S. aureus. The prevalence of nasal carriage of S. aureus was 6.3% (95% CI 5.1-7.5) out of which 16.3% (95% CI 8.9-23.8) were methicillin-resistant S. aureus (MRSA). The factors associated with nasal carriage were "child attending preschool" (OR 4.26, 95% CI 2.25-8.03; P = 0.007) or "school" (OR 3.02, 95% CI 1.27-7.18; P < 0.001) and "family size more than 10 members" (OR 2.76 95% CI 1.06-7.15; P = 0.03). The sensitivity pattern of isolated S. aureus showed resistance to commonly used oral antibiotics while resistance to glycopeptides was not noted.. We found a relatively low rate of nasal carriage of S. aureus in children below five years when compared to children of older age groups in India. Yet, prevalence of MRSA was relatively high.

Topics: Carrier State; Child, Preschool; Community-Acquired Infections; Family Characteristics; Female; Humans; India; Infant; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Prevalence; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is an important cause of infection, particularly in persons colonized with this organism. This study compared the annual prevalence and microbiological characteristics of methicillin-resistant S. aureus (MRSA) nasal colonization in Taiwanese children from 2004 through 2009. Risk factors for MRSA were determined for the overall study period.. Children from birth to ≤14 years of age presenting for health maintenance visits or attending 1 of 57 kindergartens were recruited. Nasal swabs were obtained, and a questionnaire was administered. The prevalence and microbiological characteristics of MRSA colonization were also calculated for two 3-year periods: 2004-2006 and 2007-2009.. Cultures of the anterior nares were positive for S. aureus in 824 (25.8%) of the 3,200 children, and MRSA colonization was found in 371 (11.6%) children. The prevalence of S. aureus colonization decreased from 28.1% in 2004-2006 to 23.3% in 2007-2009 (p<0.01), whereas the prevalence of MRSA colonization increased from 8.1% to 15.1% during this period (p<0.0001). Multivariate analysis revealed that the independent risk factors for MRSA carriage were different for male and female children, and also among age groups. Most MRSA isolates belonged to sequence type 59 (ST59) (86.3%); however, a multiresistant MRSA clone with ST338 background emerged in 2007-2009. Ten (62.5%) of the 16 MRSA isolates expressed the genotypic profile ST338/staphylococcal cassette chromosome mec V(T)/Panton-Valentine leukocidin-positive/staphylococcal enterotoxin B-positive, and differed only in their antimicrobial susceptibility patterns.. The prevalence of nasal colonization by MRSA increased among healthy Taiwanese children from 2004-2006 to 2007-2009, despite an overall decrease in the prevalence of nasal colonization by S. aureus. A multiresistant MRSA clone characterized as ST338 was identified from these children.

Topics: Adolescent; Child; Child, Preschool; Female; Genotype; Humans; Infant; Infant, Newborn; Male; Methicillin; Methicillin-Resistant Staphylococcus aureus; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Taiwan

Colonized or infected patients are a major reservoir for patient-to-patient transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. Despite attempted adherence to recommended infection prevention and control procedures, a general medicine unit in our hospital continued to experience ongoing transmission of MRSA. The role that colonization pressure (CP) plays in nosocomial transmission of MRSA on a general medicine unit was assessed, and a threshold CP above which additional IP&C practices should be implemented was proposed.. From January 2005 to December 2006, all patients admitted to a 36-bed general medicine unit were screened on admission for MRSA. Monthly MRSA nosocomial incidence (new nosocomial cases x 1000/susceptible patient-days) and CP (number of MRSA patient-days x 100/total patient-days) were calculated. The relative risk (RR) of MRSA transmission above and below the median CP with 95% confidence interval was calculated.. Twenty-one cases of nosocomially acquired MRSA were detected during the study period, with transmission occurring in 8 separate months. The median CP during the 2 years was 6.7%. The RR of MRSA acquisition increased as CP increased above the median (RR, 7.6; 95% CI: 1.1-52.6; P = .008). MRSA outbreaks were declared on 2 separate occasions, and, in each, the CP for the preceding month was greater than the median value of 6.7%.. CP has a significant effect on the subsequent transmission of MRSA on a general medicine unit. Ongoing monitoring of CP provides the opportunity for early implementation of enhanced infection prevention and control practices and can potentially decrease nosocomial transmission of MRSA and prevent outbreaks.

Topics: Carrier State; Catheters, Indwelling; Cross Infection; Disease Outbreaks; DNA Fingerprinting; Electrophoresis, Gel, Pulsed-Field; Hospitals; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Perineum; Prevalence; Staphylococcal Infections; Wounds and Injuries

It has been proposed that the relative scarcity of Staphylococcus aureus and Streptococcus pneumoniae cocolonization in the nasopharynxes of humans can be attributed to hydrogen peroxide-mediated interference competition. Previously it has been shown in vitro that H(2)O(2) produced by S. pneumoniae is bactericidal to S. aureus. To ascertain whether H(2)O(2) has this inhibitory effect in the nasal passages of neonatal rats, colonization experiments were performed with S. aureus and S. pneumoniae. The results of these experiments with neonatal rats are inconsistent with the hypothesis that hydrogen peroxide-mediated killing of S. aureus by S. pneumoniae is responsible for the relative scarcity of cocolonization by these bacteria. In mixed-inoculum colonization experiments and experiments where S. aureus invaded the nasopharynxes of rats with established S. pneumoniae populations, the density of S. aureus did not differ whether the S. pneumoniae strain was H(2)O(2) secreting or non-H(2)O(2) secreting (SpxB). Moreover, the advantage of catalase production by S. aureus in competition with a non-catalase-producing strain (KatA) during nasal colonization was no greater in the presence of H(2)O(2)-producing S. pneumoniae than in the presence of non-H(2)O(2)-producing S. pneumoniae.

Topics: Animals; Animals, Newborn; Antibiosis; Bacterial Proteins; Catalase; Female; Hydrogen Peroxide; Nasopharynx; Nose; Rats; Rats, Sprague-Dawley; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae

Twenty genes encoding enterotoxin and enterotoxin-like proteins have been described in Staphylococcus aureus strains. Five of these occur commonly in the enterotoxin gene cluster (egc: selo, selm, sei, seln and seg). In the sei-seln intergenic region, two pseudogenes, psient1 and psient2, can be present or an additional gene designated selu or a variant selu(v). Whilst frequencies of loci bearing pseudogenes (egc1) or the selu gene (egc2) have been reported, the distinction between selu-bearing and selu(v)-bearing (egc3) loci has rarely been made. A PCR-RFLP procedure involving cleavage of the sei-seln intergenic region by restriction endonuclease BbvI or TseI was developed that allowed differentiation of selu(+) and selu(v)(+) loci. In addition, PCR primers were designed to yield a 203 bp amplimer for sequencing of a selu or selu(v) intragenic region, which encompassed ten signature nucleotide differences. A total of 43 egc(+) human nasal isolates and 53 egc(+) bovine, ovine, caprine, leporine and gallinaceous isolates were egc typed and agr typed. None of the animal isolates was of agr type III. A total of 12 out of 17 egc3(+) human nasal isolates were of agr type III, the other 5 being agr type I. On the basis of representative multilocus sequence typing, agr type III/egc3(+) strains belonged to CC30. Human nasal isolates bearing an egc1 locus were distributed evenly across agr types I, II and III. Only two nasal isolates had an egc2 locus. All 14 agr type IV isolates, only 1 of which was of human origin, possessed an egc2 locus. The agr IV nasal isolate was fusidic acid sensitive and was found to be ST123 (CC121). There were strong associations between bovine, leporine and gallinaceous S. aureus clonal types and egc locus types. The PCR-RFLP procedure was used to screen an additional 45 S. aureus isolates from dogs, cats, rats, pigs and horses for egc locus types. Of these, 33 were egc(-). Six equine isolates were selu(+). One canine and three porcine isolates possessed pseudogenes psient1 and psient2. One porcine and one canine isolate each had the selu(v) gene. Putative relationships between disease-causing propensity and egc type need (re-)evaluation.

Topics: Animals; Bacterial Proteins; Carrier State; Cats; DNA, Bacterial; DNA, Intergenic; Dogs; Enterotoxins; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genes, Bacterial; Goats; Horses; Humans; Molecular Sequence Data; Multigene Family; Nose; Pseudogenes; Rabbits; Sheep; Staphylococcal Infections; Staphylococcus aureus; Swine; Trans-Activators

We assessed the frequency of carriers of methicillin-resistant Staphylococcus aureus (MRSA) among 500 dental patients of a university clinic. From each participant, two specimens were taken from the anterior nares and the pharynx and analysed by culture. The participants completed a questionnaire on possible risk factors of MRSA infection. Two hundred ten individuals carried S. aureus, 90 in the nares only, 51 in the throat only and 69 in nares and throat. Isolates of 208 patients were methicillin-sensitive; two isolates were methicillin-resistant, both carried in the throat exclusively. In conclusion, the frequency of nasal and/or throat carriers of MRSA among dental patients was low and suggests few opportunities of exposure in the dental clinic assessed.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacteriological Techniques; Carrier State; Colony Count, Microbial; Cross Infection; Dental Care; Female; Humans; Infection Control, Dental; Male; Methicillin; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires; Switzerland; Young Adult

The first U.S. multicenter clinical trial to assess the performance of the Cepheid Xpert MRSA assay (Xpert MRSA) was conducted. The assay is a qualitative test designed for the rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) directly from nares swabs. This novel test combines integrated nucleic acid extraction and automated real-time PCR for the detection of a MRSA-specific signature sequence. A total of 1,077 nares specimens were collected from seven geographically distinct health care sites across the United States with prevalence rates ranging from 5.2% to 44%. Nares specimens were tested by (i) the Xpert MRSA assay, (ii) direct culture on CHROMagar MRSA medium (direct CM culture), and (iii) broth-enriched culture (Trypticase soy broth with 6.5% sodium chloride) followed by plating onto CHROMagar MRSA medium (broth-enriched CM culture). When direct CM culture was designated the reference method, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Xpert MRSA assay were 94.3%, 93.2%, 73.0%, and 98.8%, respectively. When broth-enriched CM culture was used as the reference method, the clinical sensitivity, specificity, PPV, and NPV of the Xpert MRSA assay were 86.3%, 94.9%, 80.5%, and 96.6%, respectively. The BD GeneOhm MRSA (BDGO) assay was performed as a comparative molecular method. No statistical performance differences were observed between the Xpert MRSA and BDGO assays when they were compared to culture methods. From this large-scale, multicenter clinical comparison, we conclude that the Xpert MRSA assay is a simple, rapid, and accurate method for performing active surveillance for MRSA in a variety of health care populations.

Topics: Carrier State; DNA, Bacterial; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections; United States

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are emerging in southeast Queensland, Australia, but the incidence of carriage of CA-MRSA strains is unknown. The aim of this study was to assess the nasal carriage rate of S. aureus, including CA-MRSA strains, in the general adult population of southeast Queensland. 396 patients presenting to general practices in two Brisbane suburbs and 303 volunteers randomly selected from the electoral rolls in the same suburbs completed a medical questionnaire and had nasal swabs performed for S. aureus. All isolates of S. aureus underwent antibiotic susceptibility testing and single-nucleotide polymorphism (SNP) and binary typing, including determination of Panton-Valentine leukocidin (PVL). The nasal carriage rate of methicillin-susceptible S. aureus (MSSA) was 202/699 (28%), a rate similar to that found in other community-based nasal carriage studies. According to multivariate analysis, nasal carriage of S. aureus was associated with male sex, young adult age group and Caucasian ethnicity. Only two study isolates (one MSSA and one CA-MRSA) carried PVL. The nasal carriage rate of MRSA was low, at 5/699 (0.7%), and only two study participants (0.3%) had CA-MRSA strains. CA-MRSA is an emerging cause of infection in southeast Queensland, but as yet the incidence of carriage of CA-MRSA in the general community is low.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Community-Acquired Infections; DNA Fingerprinting; Exotoxins; Female; Genotype; Humans; Incidence; Leukocidins; Male; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Polymorphism, Single Nucleotide; Queensland; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To investigate the prevalence, the antibiotic resistance pattern and the population structure of Staphylococcus aureus, S. aureus isolates from the anterior nostrils of patients of general practitioners (GPs) were analysed. Insight into the S. aureus population structure is essential, as nasal carriers of S. aureus are at increased risk of developing an S. aureus infection. S. aureus was isolated from nasal swabs from 2691 patients with no sign of an infection collected in 29 GP practices in The Netherlands. The susceptibility pattern for several classes of antibiotics was determined, as well as the S. aureus genetic background, using spa typing. S. aureus was isolated from 617 of the 2691 (23%) nasal swabs. The prevalences of resistance to ciprofloxacin, co-trimoxazole, fusidic acid, macrolides and mupirocin were 0.2%, 0%, 6%, 5% and 1%, respectively. Half of the isolates were associated with a genetic background common to the major methicillin-resistant S. aureus (MRSA) clones, e.g. clonal complex (CC)1, CC5, CC8, CC22, CC30 and CC45, and the remainder were mainly associated with CC7, CC12, CC15, CC26, CC51 and CC101. The low prevalences of resistance suggest that, in the Dutch situation, S. aureus isolates from patients visiting their GP because of complaints not related to infection do not represent a large reservoir of antibiotic resistance genes. Although no MRSA isolates were found, the genetic background of some of the S. aureus isolates is commonly observed among community-associated (CA)-MRSA clones (CC1, CC8 and CC30), and this might suggest that these isolates have the potential to become CA-MRSA.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Child; DNA Fingerprinting; DNA, Bacterial; Family Practice; Genotype; Humans; Microbial Sensitivity Tests; Middle Aged; Netherlands; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To measure the rate of colonization of outborn infants with methicillin-resistant Staphylococcus aureus (MRSA) to evaluate the need for Contact Precautions (including isolation) at the time of admission to the neonatal intensive care unit (NICU).. All 239 consecutive infants referred from the neonatal units of other hospitals to a tertiary NICU in Al Ain, United Arab Emirates, between January 2000 and December 2007 were screened for MRSA colonization. Swabs from the ear, nose, rectum, axillae, and groin were obtained from each patient, and the rates of colonization were calculated retrospectively.. Some 72% of newborns were admitted to our NICU in the first week. Only 1 patient, admitted from Oman, grew MRSA from the ear swab (rate, 0.4%; 95% confidence interval = 0.01% approximately 2.3%).. This study from a tertiary NICU in a developing country shows that outborn infants are unlikely to harbor MRSA, and thus their routine admission in a single-bed isolation room is not justified. MRSA screening on admission has a very low yield and does not appear to be cost-effective. Contact Precautions should be reserved for those newborns transferred from general pediatric wards and those admitted from home.

Topics: Carrier State; Cross Infection; DNA, Bacterial; Ear, External; Hospitals, Pediatric; Humans; Infant, Newborn; Infection Control; Intensive Care Units, Neonatal; Methicillin-Resistant Staphylococcus aureus; Nose; Patient Isolation; Rectum; Referral and Consultation; Retrospective Studies; Risk Factors; Skin; Staphylococcal Infections; United Arab Emirates

Persistent carriers have a higher risk of Staphylococcus aureus infections than noncarriers but a lower risk of bacteremia-related death. Here, the role played by anti-staphylococcal antibodies was studied.. Serum samples from 15 persistent carriers and 19 noncarriers were analyzed for immunoglobulin (Ig) G, IgA, and IgM binding to 19 S. aureus antigens, by means of Luminex technology. Nasal secretions and serum samples obtained after 6 months were also analyzed.. Median serum IgG levels were significantly higher in persistent carriers than in noncarriers for toxic shock syndrome toxin (TSST)-1 (median fluorescence intensity [MFI] value, 11,554 vs. 4291; P < .001) and staphylococcal enterotoxin (SE) A (742 vs. 218; P < .05); median IgA levels were higher for TSST-1 (P < .01), SEA, and clumping factor (Clf) A and B (P < .05). The in vitro neutralizing capacity of anti-TSST-1 antibodies was correlated with the MFI value (R(2) = 0.93) and was higher in persistent carriers (90.6% vs. 70.6%; P < .05). Antibody levels were stable over time and correlated with levels in nasal secretions (for IgG, R(2) = 0.87; for IgA, R(2) = 0.77).. Antibodies to TSST-1 have a neutralizing capacity, and median levels of antibodies to TSST-1, SEA, ClfA, and ClfB are higher in persistent carriers than in noncarriers. These antibodies might be associated with the differences in the risk and outcome of S. aureus infections between nasal carriers and noncarriers.

Topics: Antibodies, Bacterial; Antibody Specificity; Antigens, Bacterial; Bacterial Toxins; Carrier State; Enterotoxins; Humans; Immunoglobulin G; Neutralization Tests; Nose; Reproducibility of Results; Staphylococcal Infections; Staphylococcus aureus; Superantigens

Since patient exchange between hospitals sharing a common catchment area might favour regional spread of meticillin-resistant Staphylococcus aureus (MRSA), the reliable detection of patients colonised at admission is crucial. Thus, hospitals in the Dutch-German border area EUREGIO MRSA-net aim at synchronising their local MRSA standards in order to prevent unidentified inter-hospital as well as cross-border spread. This assumes enhanced knowledge of MRSA prevalence and risk factors associated with MRSA carriage at admission. We conducted nasal MRSA screening of all inpatients admitted to 39 German hospitals (in the period 1 November to 30 November 2006) and to one Dutch hospital (in the period 1 July to 30 September 2007) in the EUREGIO MRSA-net. A total of 390 MRSA cases were detected among 25,540 patients screened. The admission prevalence was 1.6 MRSA/100 patients (6.5% of all S. aureus) in the German and 0.5 MRSA/100 patients (1.4% of all S. aureus) in the Dutch part of the border region. Overall, the predominating S. aureus protein A gene (spa) sequence types were t003, t032 and t011. One isolate (t044) carried Panton-Valentine leukocidin (PVL) encoding genes. Altogether, 79% and 67% of all MRSA patients in the German and Dutch regions respectively, were identifiable by the classical nosocomial risk factors assessed. In patients lacking all risk factors assessed, spa types t011 and t034 were predominant (P<0.001).

Topics: Bacterial Toxins; Bacterial Typing Techniques; Carrier State; DNA, Bacterial; Exotoxins; Genotype; Germany; Hospitals; Humans; Leukocidins; Methicillin-Resistant Staphylococcus aureus; Netherlands; Nose; Patient Admission; Prevalence; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcal Protein A

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important cause of skin and soft-tissue infections (SSTI). The understanding of the molecular epidemiology and virulence of MRSA continues to expand. From January 2005 to December 2005, we screened soldiers for MRSA nasal colonization, administered a demographic questionnaire, and monitored them prospectively for SSTI. All MRSA isolates underwent molecular analysis, which included pulsed-filed gel electrophoresis (PFGE) and PCR for Panton-Valentine leukocidin (PVL), the arginine catabolic mobile element (ACME), and the staphylococcal cassette chromosome mec (SCCmec). Of the 3,447 soldiers screened, 134 (3.9%) had MRSA colonization. Of the 3,066 (89%) who completed the study, 39 developed culture-confirmed MRSA abscesses. Clone USA300 represented 53% of colonizing isolates but was responsible for 97% of the abscesses (P < 0.001). Unlike colonizing isolates, isolates positive for USA300, PVL, ACME, and type IV SCCmec were significantly associated with MRSA abscess isolates. As determined by multivariate analysis, risk factors for MRSA colonization were a history of SSTI and a history of hospitalization. Although various MRSA strains may colonize soldiers, USA300 is the most virulent when evaluated prospectively, and PVL, ACME, and type IV SCCmec are associated with these abscesses.

Topics: Abscess; Bacterial Toxins; Carrier State; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Genotype; Humans; Leukocidins; Methicillin-Resistant Staphylococcus aureus; Military Personnel; Molecular Epidemiology; Nose; Risk Factors; Staphylococcal Infections; Staphylococcal Skin Infections; Surveys and Questionnaires; Virulence Factors

Topics: Carrier State; England; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Pharynx; Sensitivity and Specificity; Staphylococcal Infections; Wales

We studied provider- and patient-collected samples from multiple anatomic sites to determine the yield for detection of methicillin-resistant Staphylococcus aureus (MRSA). Sampling of multiple sites was required to achieve a sensitivity of more than 90% for MRSA colonization. Groin and perineum samples yielded positive results significantly more often for community-onset MRSA than for hospital-onset MRSA. Agreement rates between provider- and patient-collected swab specimens were excellent.

Topics: Adolescent; Aged; Anti-Bacterial Agents; Axilla; Child; Community-Acquired Infections; Cross Infection; Cross-Sectional Studies; Culture Media; Female; Groin; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Pharynx; Population Surveillance; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections

The anterior nares are the most sensitive single site for detecting methicillin-resistant Staphylococcus aureus (MRSA) colonization. Colonization patterns of USA300 MRSA colonization are unknown.. To assess whether residents of extended care facilities who are colonized with USA300 MRSA have different nares or skin colonization findings, compared with residents who are colonized with non-USA300 MRSA strains.. The study population included residents of 5 extended care units in 3 separate facilities who had a recent history of MRSA colonization. Specimens were obtained weekly for surveillance cultures from the anterior nares, perineum, axilla, and skin breakdown (if present) for 3 weeks. MRSA isolates were categorized as USA300 MRSA or non-USA300 MRSA.. Of the 193 residents who tested positive for MRSA, 165 were colonized in the anterior nares, and 119 were colonized on their skin. Eighty-four percent of USA300 MRSA-colonized residents had anterior nares colonization, compared with 86% of residents colonized with non-USA300 MRSA (P= .80). Sixty-six percent of USA300 MRSA-colonized residents were colonized on the skin, compared with 59% of residents colonized with non-USA300 MRSA (P= .30).. Colonization patterns of USA300 MRSA and non-USA300 MRSA are similar in residents of extended care facilities. Anterior nares cultures will detect most--but not all--people who are colonized with MRSA, regardless of whether it is USA300 or non-USA300 MRSA.

Topics: Baltimore; Community-Acquired Infections; Female; Hospitals, Veterans; Humans; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Prevalence; Skilled Nursing Facilities; Skin; Staphylococcal Infections

The aim of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) at Namazi Hospital, Shiraz, Iran.. This cross-sectional study was conducted from July to November 2006. Nasal swabs were taken from 600 randomly selected HCWs. The isolates were identified as S. aureus based on morphology, Gram stain, catalase test, coagulase test, and mannitol salt agar fermentation. To analyze sensitivity patterns of MRSA strains more precisely, minimum inhibitory concentrations (MICs) of antibiotics were determined by the E-test method. All methicillin-resistant isolates were examined for the existence of the mecA gene by total DNA extraction and PCR.. The prevalence of nasal carriage of methicillin-sensitive S. aureus (MSSA) was 25.7% and of MRSA was 5.3%, with the highest nasal carriage of MRSA in surgical wards and the emergency department. There was no significant difference between the sexes (p=0.247), age (p=0.817), and years of healthcare service (p=0.15) with regard to the nasal carriage of MRSA and MSSA. In the univariate analysis, a statistically significant difference was only found for occupation (p=0.032) between the carriage of MSSA and MRSA. In the multivariate analysis, the occupation 'nurse' was independently associated with MRSA carriage (p=0.012, odds ratio 3.6, 95% confidence interval 1.3-9.7). The highest resistance rate for both gentamicin and clindamycin (69%) was noted among the MRSA strains. None of the MRSA strains were resistant to mupirocin, linezolid, fusidic acid, or vancomycin. The existence of the mecA gene in all 32 methicillin-resistant isolates was observed by PCR.. This study revealed the prevalence of nasal carriage of S. aureus strains among HCWs to be lower than that found in other studies from Iran. The antibiotic susceptibility patterns also differed, perhaps as a result of the excessive use of antibiotics at our hospital. Only the occupation of nurse was an independent risk factor for MRSA carriage.

Topics: Adult; Aged; Anti-Bacterial Agents; Carrier State; Clindamycin; Cross-Sectional Studies; Drug Resistance, Bacterial; Female; Gentamicins; Health Personnel; Humans; Iran; Male; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Middle Aged; Nose; Polymerase Chain Reaction; Prevalence; Staphylococcal Infections; Young Adult

Topics: Clinical Laboratory Techniques; Computer Systems; Humans; Laboratories, Hospital; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Population Surveillance; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United States

To determine the rate of Staphylococcus aureus nasal colonization at admission to intensive care units (ICU) and assess its effect on the development of an ICU-acquired S aureus infection.. We screened all ICU admissions for nasal colonization within the Calgary Health Region from October 2005 to September 2006 and followed up patients to hospital discharge or death or S aureus infection to 30 days.. One thousand three hundred eight patients were admitted to ICU for more than 48 hours and screened for nasal colonization. Fifty (4%) were methicillin-resistant S aureus (MRSA)-positive, 311 (24%) were methicillin-sensitive S aureus (MSSA)-positive, and 947 (72%) were nasal screen-negative. Overall, 5% (63/1239) of patients uninfected at ICU admission developed an ICU-acquired S aureus infection. The rate of ICU-acquired infection was 5% in MRSA colonized patients, 12% in MSSA colonized patients, and 3% in noncolonized patients. A positive nasal screen (odds ratio [OR], 4.7; 95% confidence interval [CI] 2.7-7.9), neuro/trauma patients (OR, 3.1; 95% CI, 1.8-5.2), and higher first Therapeutic Intervention Scoring System score (OR, 1.03 per point; 95% CI, 1.01-1.05) were independent predictors for developing an ICU-acquired S aureus infection.. Nasal colonization with S aureus is a significant risk factor for ICU-acquired S aureus infections, and strategies to control these infections should target both MSSA and MRSA colonization.

Topics: Aged; Critical Illness; Female; Humans; Intensive Care Units; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

Healthy infants frequently acquire Staphylococcus aureus colonization; however, the modes of transmission are not well defined. In this study, 8 of 23 (35%) infants cultured at age 2 weeks acquired S aureus carriage, but only 1 infant had a family member with nasal carriage of the same clone, suggesting that sources other than colonized family members may account for a significant proportion of cases.

Topics: Carrier State; Cross Infection; Feces; Female; Humans; Infant, Newborn; Male; Methicillin-Resistant Staphylococcus aureus; Mothers; Nose; Pilot Projects; Prospective Studies; Skin; Staphylococcal Infections; Staphylococcus aureus

A nested case-control study at a tertiary care facility was conducted to assess potential risk factors for colonization with methicillin-resistant Staphylococcus aureus (MRSA) on admission among oncology patients. Risk factors for any S aureus and MRSA colonization on admission in oncology patients are consistent with previous studies in general populations. In addition, recent chemotherapy as a risk factor is a unique finding in this population.

Topics: Antineoplastic Agents; Carrier State; Case-Control Studies; Cross Infection; Female; Hospitalization; Humans; Immunocompromised Host; Infection Control; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Odds Ratio; Oncology Service, Hospital; Patient Admission; Retrospective Studies; Risk Factors; Staphylococcal Infections

We investigated an outbreak of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections that occurred among healthcare workers (HCWs) but not among residents of a long-term care facility (LTCF).. Cases of S. aureus infection were sought by reviewing the medical records of residents and HCWs. In order to identify risk factors for the development of an S. aureus infection, an unmatched case-control study was conducted. Cases were all HCWs with a clinically compatible S. aureus infection; controls were HCWs with no history of a clinically compatible S. aureus infection. Cases and controls were interviewed and anterior nasal swabs were collected.. Over a period of 14 months, a total of eight cases were identified among practice nurses, giving an attack rate of 10% for this category of profession. All isolates were identified as MRSA Panton-Valentine leukocidin (PVL)-producing SCCmec type IV. By multivariate analysis, working in a specific zone and being a practice nurse were found to be statistically significant risk factors for infection.. The current outbreak indicates that HCWs may serve as vehicles for the entry of PVL-positive MRSA strains from the community into LTCFs, and that deficient hygiene practices and unrecognized carriage may facilitate spread. Given the increasing prevalence of PVL-positive MRSA infections worldwide, guidelines for the eradication of PVL-positive MRSA carriage within closed communities should be established and efforts to obtain cultures from compatible infections should be made.

Topics: Adult; Bacterial Toxins; Carrier State; Case-Control Studies; Disease Outbreaks; Exotoxins; Female; Health Personnel; Humans; Interviews as Topic; Leukocidins; Long-Term Care; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Risk Factors; Staphylococcal Infections

Polymorphisms in the vitamin D receptor (VDR) gene have been associated with susceptibility to several diseases, including type 1 diabetes (T1D) and infections. In this study we investigated whether VDR gene polymorphisms influence nasal carriage of Staphylococcus aureus in individuals with T1D.. In 93 T1D patients, VDR polymorphisms on FokI F>f, BsmI B>b, ApaI A>a, and TaqI T>t were determined in DNA extracted from peripheral blood leukocytes, and a nasal swab was obtained to detect colonization by S. aureus. A repeat swab was obtained in 76/93 subjects for the estimation of persistent S. aureus carriage.. The prevalence of S. aureus nasal colonization was 31.2% and the prevalence of persistent carriage was 25%. The presence of TaqI T allele was related to higher rates of S. aureus colonization, and TaqI TT homozygotes were more colonized (48.5% vs. 21.7%; p 0.007; OR 3.40, 95% CI 1.36-8.52) and more persistent carriers (37.9% vs. 17.0%; p 0.039; OR 2.98, 95% CI 1.02-8.67). The presence of ApaI A allele was related to lower rates of S. aureus colonization, and ApaI AA homozygotes were less colonized (17.6% vs. 39.0%; p 0.026; OR 0.34, 95% CI 0.12-0.94) and less persistent carriers (11.5% vs. 32%; p 0.043; OR 0.28, 95% CI 0.07-1.06). No differences were observed for BsmI and FokI genotypes.. Our findings suggest that VDR polymorphisms may be associated with nasal carriage of S. aureus in individuals with T1D, and further contribute to the better understanding of the immunomodulatory role of vitamin D in the human host's response and susceptibility to infection.

Topics: Adolescent; Adult; Carrier State; Child; Child, Preschool; Diabetes Complications; Diabetes Mellitus, Type 1; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Nose; Polymorphism, Genetic; Prevalence; Receptors, Calcitriol; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Young Adult

To determine the rates of and risk factors for carriage and acquisition of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae during hospitalization.. Cohort study.. Shaare Zedek Medical Center, a 550-bed teaching hospital.. During a 5-month period (February 1-June 30, 2004), 167 (8%) of 1,985 newly admitted general medical patients were enrolled in our study. Nasal, oropharyngeal, and rectal swab specimens were obtained at admission and every 2-3 days until hospital discharge or death. Enterobacteriaceae isolates were tested for ESBL, and Staphylococcus aureus isolates were tested for methicillin resistance.. Of the 167 patients enrolled in our study, 15 (9%) were identified as nasal carriers of methicillin-resistant S. aureus (MRSA) at admission, and 13 (8%) were rectal carriers of ESBL-producing Enterobacteriaceae at admission. Univariate risk factors for rectal carriage of ESBL-producing Enterobacteriaceae included female sex (odds ratio [OR], 11 [95% confidence interval {CI}, 1.4-238]; P < .05), nursing home residence (OR, 6.9 [95% CI, 1.8-27]; P < .01), recent antibiotic treatment (OR, 9.8 [95% CI, 1.7-74]; P < .05), and concomitant nasal carriage of MRSA and/or ESBL-producing Enterobacteriaceae (OR, 5.8 [95% CI, 1.2-26]; P < .01). Multivariate risk factors were female sex and recent antibiotic treatment. During hospitalization, 35 (21%) of 167 patients had acquired rectal carriage of ESBL-producing Enterobacteriaceae (P = .002, for trend analysis). Of the 12 patients who were still in the hospital 2 weeks after admission, 4 (33%) were carriers of ESBL-producing Enterobacteriaceae. Univariate risk factors for acquisition included an age of older than 65 years (P < .005), nursing home residence (OR 2.6, [95% CI, 0.98-2.6]), impaired cognition (OR, 4.8 [95% CI, 1.9-12]), recent antibiotic treatment (OR, 2.7 [95% CI, 0.9-8.3]), respiratory assistance (OR, 4.2 [95% CI, 1.2-14]), and prolonged hospitalization. Multivariate risk factors were an age of older than 65 years and broad-spectrum antibiotic therapy.. Rectal carriage of ESBL-producing Enterobacteriaceae occurred in 13 (8%) of 167 patients at admission to the medical departments of our hospital and in 4 (33%) of 12 patients still remaining in our hospital after 2 weeks.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; beta-Lactamases; Carrier State; Enterobacteriaceae; Enterobacteriaceae Infections; Female; Hospitalization; Humans; Israel; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Rectum; Risk Factors; Staphylococcal Infections

The anterior nares are the major reservoir in humans of Staphylococcus aureus with the risk of developing endogenous infections or transmitting infections to susceptible persons. The mechanisms that mediate attachment of staphylococci to the nasal mucosa are little known. The purpose of the present work was to study some factors that could influence the nasal colonization in an animal model of mice. We investigated the possible role of IFN-gamma. We used S. aureus ATCC 35556 (SA113) slime-producing and ATCC 25923 non-slime-producing strains. Male 6-week-old BALB/c, C57BL/6 (wild-type, WT), and gene-deficient IL-12p40 (IL-12p40-/-) or IL-4 (IL-4-/-) mice on C57BL/6 background were infected with a dose of S. aureus of 10(6) CFU in 10mul of saline. The total number of S. aureus CFU per nose and lung, specific IgA response and IFN-gamma levels were evaluated. Significant higher CFU were recovery from the narines of C57BL/6 compared with BALB/c mice either after ATCC 35556 (p<0.0001) and ATCC 25923 (p<0.02) strain infection. Low IgA response correlated with high bacterial counting in the C57BL/6 nasal region. Moreover, C57BL/6 mice showed major colonization of slime-producing S. aureus ATCC 35556 than non-slime-producing ATCC 25923 S. aureus strain (p<0.02). IL-12p40-/-mice clarified the bacteria from their nose more efficiently that WT mice after slime-producing S. aureus (p<0.0001). Accordingly, significant lower level of IFN-gamma were detected in IL-12p40-/- compared with WT mice after infection with this strain (p<0.03). The results suggested the influence of the slime production in nasal colonization of S. aureus, and indicate at first time that IFN-gamma may play a detrimental role in this mucosal infection. These results could contribute to elucidate mucosal immune mechanisms involved in S. aureus colonization and then control infections in susceptible persons.

Topics: Animals; Interferon-gamma; Interleukin-12 Subunit p40; Interleukin-4; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Nose; Staphylococcal Infections; Staphylococcus aureus

To determine whether dogs that visited human health-care facilities were at greater risk of acquiring certain health-care-associated pathogens, compared with dogs performing animal-assisted interventions in other settings, and to identify specific behaviors of dogs associated with an increased risk of acquiring these pathogens.. Prospective cohort and nested case-control studies.. 96 dogs that visited human health-care facilities and 98 dogs involved in other animal-assisted interventions.. Fecal samples and nasal swab specimens were collected from dogs at the time of recruitment and every 2 months for 1 year and were tested for methicillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile, and other selected bacteria. Information was also obtained on facilities visited during animal-assisted interventions, dog diet, dog illnesses, and antimicrobial use within the home. At the end of the study, dog handlers were asked about the behavior of their dogs during visits to health-care facilities.. Rates of acquisition of MRSA and C difficile were 4.7 and 2.4 times as high, respectively, among dogs that visited human health-care facilities, compared with rates among dogs involved in other animal-assisted interventions. Among dogs that visited human health-care facilities, those that licked patients or accepted treats during visits were more likely to be positive for MRSA and C difficile than were dogs that did not lick patients or accept treats.. Results suggested that dogs that visited human health-care facilities were at risk of acquiring MRSA and C difficile, particularly when they licked patients or accepted treats during visits.

Topics: Animals; Carrier State; Case-Control Studies; Clostridioides difficile; Clostridium Infections; Cohort Studies; Data Collection; Dog Diseases; Dogs; Feces; Health Facilities; Humans; Methicillin-Resistant Staphylococcus aureus; Nose; Ontario; Risk Factors; Staphylococcal Infections; Surveys and Questionnaires

Topics: Adult; Carrier State; Humans; Incidence; Malaysia; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus; Students; Universities; Young Adult

In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness.

Topics: Bacteremia; Enterotoxins; Genotype; Hospitals; Humans; Korea; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Staphylococcus aureus

This study investigates the effectiveness of a same-day polymerase chain reaction (PCR) test for the rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) in a general screening of patients admitted to the trauma surgery and heart surgery department in a German university hospital. A total of 442 patients were screened over a 4-month period by using a PCR assay, compared to culture methods, for specimens from the nose and throat. The MRSA carriage rate on admission was 3.85% during the study period. The PCR results of 1,680 swabs showed a sensitivity of 85% and a specificity of 99.39% for swabs from the nares and for the throat 42.11% and 98.78%, respectively. A combination of specimens from the nose and throat from the same patient led to a sensitivity of 100% with a specificity of 98.29%. Cost calculation under the circumstances of a diagnosis-related groups (DRG) payment system found that the eight MRSA-positive patients created costs of 38,472 euros, i.e. 4,809 euros per patient, facing screening costs of 36.62 euros per sample. Screening patients by using the rapid PCR assay for a combination of specimens from the nose and throat would offer a safe and cost-effective way of MRSA screening on admission.

Topics: Carrier State; Cost-Benefit Analysis; Culture Techniques; Diagnosis-Related Groups; Germany; Humans; Inpatients; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Molecular Diagnostic Techniques; Nose; Pharynx; Polymerase Chain Reaction; Prevalence; Sensitivity and Specificity; Staphylococcal Infections; Surgery Department, Hospital; Time Factors

The purpose of this study was to determine the most sensitive strategy for the detection of Staphylococcus aureus among pregnant women and newborn infants.. We obtained cultures for S aureus from 5 body sites of women at 35-37 weeks' gestation. We obtained cultures from their newborn infants before hospital discharge.. Of 209 women who were screened, 29% of the women had at least 1 culture that was positive for S aureus; 5% of infants were S aureus carriers. The sensitivities of each site for S aureus detection were 52% nares, 50% throat, 13% rectum, 8% vagina, and 10% skin. The most sensitive combination of 2 sites was nares and throat (88%). Perinatal transmission of S aureus occurred in 4 women. Maternal methicillin-resistant S aureus carriage rate was 1%. Two infants carried the USA300 methicillin-resistant S aureus.. Screening single body sites is insensitive for the detection of S aureus carriage in pregnancy. Sampling nares and throat is essential to the identification of S aureus carriers.

Topics: Carrier State; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Infant, Newborn; Nose; Pharynx; Pregnancy; Pregnancy Complications, Infectious; Prospective Studies; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

Few data are available on methicillin-resistant Staphylococcus aureus (MRSA) colonization in day care. We performed a study in a medical university child care center to study the epidemiology of MRSA in this population.. Survey.. A child care center on the campus of a university medical center.. One hundred four children who attended the child care center and 32 employees gave samples that were cultured for MRSA. Seventeen household members of the children and employee found to be colonized with MRSA also gave samples that were cultured. Parents and employees completed questionnaires about demographic characteristics, medical conditions and treatments, and possible exposure risks outside the child care center. In addition, 195 environmental samples were taken from sites at the childcare center. Isolates were analyzed for relatedness by use of molecular typing, and statistical analysis was performed.. The prevalence of MRSA in the children was 6.7%. One employee (3.1%) was colonized with MRSA. Cultures of samples given by 6 of 17 (35.3%) family members of these children and the employee yielded MRSA. MRSA was recovered from 4 of 195 environmental samples. Molecular typing revealed that many of the MRSA isolates were indistinguishable, and 18 of the 21 isolates were community-associated MRSA. Multivariable analysis revealed that receipt of macrolide antibiotics (P = .002; odds ratio, 39.6 [95% confidence interval, 3.4-651.4]) and receipt of asthma medications (P = .024; odds ratio, 26.9 [95% confidence interval, 1.5-500.7]) were related to MRSA colonization.. There was a low prevalence of MRSA colonization in children and employees in the child care center but a higher prevalence of colonization in their families. Molecular typing showed that transmission of MRSA likely occurred in the child care center. The use of macrolide antibiotics and asthma medications may increase the risk of MRSA colonization in this population.

Topics: Academic Medical Centers; Adult; Carrier State; Child Day Care Centers; Child, Preschool; Community-Acquired Infections; Cross Infection; Culture Media; Female; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Nose; Oropharynx; Prevalence; Staphylococcal Infections; Texas

Complications of primary nasoplasty, at the time of definitive primary cheiloplasty, are underreported in the literature. This study endeavors to examine the occurrences of these complications at our cleft-craniofacial center, in an effort to identify causative factors and management strategies. A case series of patients with postoperative nasal complications after primary cleft lip nasal surgery is presented.. A retrospective chart review of primary cleft lip nasal repairs was conducted at our cleft-craniofacial center between January 2003 and December 2007. Consecutive cases of 3 staff surgeons were evaluated. Specific data points included number and type of complications, subsequent required interventions, and relevant history, with particular attention paid to the details of the primary nasoplasty.. Eighty-six primary cleft lip nasoplasties were completed between the years 2003 and 2007. Six complications (6.9%) related to the primary cleft lip nasoplasty were identified. Four patients (4.6%) experienced nasal tip infections; all 4 required surgical drainage. Twenty-four patients (27.9%) undergoing primary cleft lip and nose repair had postoperative nostril conformers placed, and 2 (8.3%) of them experienced complications deemed conformer related.. Postoperative nasal complications of primary cheiloplasty occur and are likely underreported. In this series, complications resulted from infection, often occurring late, and secondary to the use of nostril conformers. Surgeon awareness and caregiver education, to identify the early signs of postoperative nasal complications, are critical to the successful treatment of these occurrences. Although this study did not intend on examining antibiotic use, the significance of nasal tip infections might support the regular use of antibiotics in this population, and the use of postoperative nostril conformers must be followed closely.

Topics: Abscess; Cleft Lip; Drainage; Female; Follow-Up Studies; Haemophilus Infections; Haemophilus influenzae; Humans; Infant; Male; Nasal Cartilages; Nose; Nose Diseases; Plastic Surgery Procedures; Postoperative Complications; Retrospective Studies; Staphylococcal Infections; Surgical Fixation Devices; Surgical Wound Infection; Suture Techniques

Investigations regarding Staphylococcus aureus carriage among Brazilian children are scarce. We evaluated the determinants of S. aureus and methicillin-resistant S. aureus (MRSA) nasal carriage in infants attending day care centers (DCCs) and the molecular features of the MRSA strains. A total of 1,192 children aged 2 months to 5 years attending 62 DCCs were screened for S. aureus and MRSA nasal carriage. MRSA isolates were characterized by pulsed-field gel electrophoresis, multilocus sequence typing, spa typing, staphylococcal cassette chromosome (SCC) mec typing and the presence of the Panton-Valentine leukocidin gene. Logistic regression was performed to determine risk factors associated with S. aureus and MRSA colonization. S. aureus and MRSA carriage were detected in 371 (31.1%) and 14 (1.2%) children, respectively. Variables found to be independently associated with an increased risk for S. aureus carriage included being older than 24 months (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3 to 2.6) and previous DCC attendance (OR, 1.5; 95% CI, 1.0 to 2.2). Having a mother with a high level of education was a protective factor for nasal colonization (OR, 0.4; 95% CI, 0.2 to 0.8). Moreover, we observed that more children carrying MRSA had younger siblings than children not colonized by MRSA. Among the 14 MRSA strains, three SCCmec types (IIIA, IV, and V) were detected, together with a multidrug-resistant dominant MRSA lineage sharing 82.7% genetic similarity with the Brazilian clone (ST239-MRSA-IIIA; ST indicates the sequence type determined by multilocus sequence typing). Although SCCmec type V was recovered from one healthy child who had been exposed to known risk factors for hospital-associated MRSA, its genetic background was compatible with community-related MRSA. Our data suggest that DCC attendees could be contributing to MRSA cross-transmission between health care and community settings.

Topics: Brazil; Carrier State; Child Day Care Centers; Child, Preschool; Cross-Sectional Studies; Female; Humans; Infant; Male; Methicillin-Resistant Staphylococcus aureus; Molecular Epidemiology; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The BD GeneOhm MRSA PCR assay (Becton Dickinson, USA) is a qualitative real-time PCR test for rapid detection of nasal colonization of methicillin-resistant Staphylococcus aureus (MRSA). We evaluated the performance of BD GeneOhm MRSA PCR assay versus MRSASelect (Bio-Rad, France) and broth enrichment cultures for detection of MRSA from nasal swabs.. From August 2008 to January 2009, 295 nasal swabs were taken from patients in intensive care units and transported to the laboratory with BD CultureSwab Liquid Stuart Single Swab (Becton Dickinson, USA). The swabs were inoculated onto MRSASelect first and then suspended into GeneOhm sample buffer: 100 microL of the suspension was inoculated into 6.5% NaCl-tryptic soy broth (Becton Dickinson, USA), which was subcultured on MRSASelect after overnight incubation (TSBS). Performances of GeneOhm MRSA and MRSASelect were compared to TSBS.. With GeneOhm MRSA, 125 swabs (44.6%) were positive for MRSA, 13 (4.4%) were unresolved, and 2 were not determined. With MRSASelect and TSBS 86 (29.4%) and 106 swabs (36.2%), respectively, were positive. The sensitivity, specificity, and positive and negative predictive value of GeneOhm MRSA were 85.8%, 77.5%, and 72.8% and 93.5%, respectively, and corresponding values for MRSASelect were 78.3%, 94.8%, and 96.5% and 88.9%. Of the 33 patients whose 34 specimens were found false positive in GeneOhm MRSA, 23 patients were MRSA-positive either previously or subsequently to this study. All of the 10 patients with false-negative specimens in GeneOhm MRSA PCR assay were previously MRSA or methicilln-resistant coagulase negative staphylococci (MRCNS)-positive and were treated for MRSA, but they became MRSA-positive after 1 to 4 negative surveillance cultures.. GeneOhm MRSA PCR assay showed a relatively high negative predictive value. However, its low specificity and frequent occurrence of unresolved results would be problematic in the endemic areas with a high prevalence of MRSA.

Topics: Endemic Diseases; Humans; Intensive Care Units; Methicillin-Resistant Staphylococcus aureus; Nose; Polymerase Chain Reaction; Reagent Kits, Diagnostic; Sensitivity and Specificity; Staphylococcal Infections

Topics: Bacterial Typing Techniques; Culture Media; Humans; Mass Screening; Methicillin-Resistant Staphylococcus aureus; Nose; Perineum; Pharynx; Staphylococcal Infections

To determine the zoonotic risk from meticillin-resistant staphylococcal species or transfer of resistance genes between dogs with pyoderma and their owners, 25 dog-owner pairs were studied. Cultures were obtained from the dog's lesions and the owner's nasal cavity on the initial visit. Staphylococcus isolates were identified and antimicrobial susceptibility tests were performed by the Kirby-Bauer disk diffusion method. Presence of the mecA gene was determined by PCR. Staphylococcal Cassette Chromosome (SCCmec) typing was performed by multiplex PCR. Eighteen dogs had a meticillin-resistant staphylococcal species, with meticillin-resistant S. pseudintermedius (MRSP) isolated from 15 dogs. MRSP was isolated from two owners of dogs with MRSP skin infections. Both organisms had the same susceptibility pattern and SCCmec type. MRSP was not isolated from the owners after treating both dogs for 1 month. At least one coagulase-negative Staphylococcus spp. (CoNS) was isolated from each owner, with meticillin resistance found in 16 (64%) of the isolates. The mecA gene was identified in all but two of the meticillin-resistant Staphylococcus spp. Multiplex PCR identified SCCmec type V in all MRSP. The mecA gene-possessing CoNS isolates from owners contained either SCCmec type IVa or IVc. In conclusion, MRSP colonization of owners appeared to be uncommon and transient. Human nasal carriage of meticillin-resistant CoNS was common, but the SCCmec types were different from those in the canine MRSP isolates. Owners do not appear to be at great risk of zoonotic transfer of organisms or antimicrobial resistance genes from dogs with MRSP infections, but the findings should be confirmed with a much larger cohort.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Dog Diseases; Dogs; Humans; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus; Zoonoses

To evaluate the efficacy of a standardized regimen for decolonization of methicillin-resistant Staphylococcus aureus (MRSA) carriers and to identify factors influencing decolonization treatment failure.. Prospective cohort study from January 2002 to April 2007, with a mean follow-up period of 36 months.. University hospital with 750 beds and 27,000 admissions/year.. Of 94 consecutive hospitalized patients with MRSA colonization or infection, 32 were excluded because of spontaneous loss of MRSA, contraindications, death, or refusal to participate. In 62 patients, decolonization treatment was completed. At least 6 body sites were screened for MRSA (including by use of rectal swabs) before the start of treatment.. Standardized decolonization treatment consisted of mupirocin nasal ointment, chlorhexidine mouth rinse, and full-body wash with chlorhexidine soap for 5 days. Intestinal and urinary-tract colonization were treated with oral vancomycin and cotrimoxazole, respectively. Vaginal colonization was treated with povidone-iodine or, alternatively, with chlorhexidine ovula or octenidine solution. Other antibiotics were added to the regimen if treatment failed. Successful decolonization was considered to have been achieved if results were negative for 3 consecutive sets of cultures of more than 6 screening sites.. The mean age (+/- standard deviation [SD]) age of the 62 patients was 66.2 +/- 19 years. The most frequent locations of MRSA colonization were the nose (42 patients [68%]), the throat (33 [53%]), perianal area (33 [53%]), rectum (36 [58%]), and inguinal area (30 [49%]). Decolonization was completed in 87% of patients after a mean (+/-SD) of 2.1 +/- 1.8 decolonization cycles (range, 1-10 cycles). Sixty-five percent of patients ultimately required peroral antibiotic treatment (vancomycin, 52%; cotrimoxazole, 27%; rifampin and fusidic acid, 18%). Decolonization was successful in 54 (87%) of the patients in the intent-to-treat analysis and in 51 (98%) of 52 patients in the on-treatment analysis.. This standardized regimen for MRSA decolonization was highly effective in patients who completed the full decolonization treatment course.

Topics: Aged; Aged, 80 and over; Anal Canal; Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Chlorhexidine; Female; Humans; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Pharynx; Povidone-Iodine; Rectum; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination; Vancomycin

We sought to define the prevalence of and risk factors for methicillin-resistant Staphylococcus aureus nasal colonization in the St Louis pediatric population.. Children from birth to 18 years of age presenting for sick and well visits were recruited from pediatric practices affiliated with a practice-based research network. Nasal swabs were obtained, and a questionnaire was administered.. We enrolled 1300 participants from 11 practices. The prevalence of methicillin-resistant S aureus nasal colonization varied according to practice, from 0% to 9% (mean: 2.6%). The estimated population prevalence of methicillin-resistant S aureus nasal colonization for the 2 main counties of the St Louis metropolitan area was 2.4%. Of the 32 methicillin-resistant S aureus isolates, 9 (28%) were health care-associated types and 21 (66%) were community-acquired types. A significantly greater number of children with community-acquired methicillin-resistant S aureus were black and were enrolled in Medicaid, in comparison with children colonized with health care-associated methicillin-resistant S aureus. Children with both types of methicillin-resistant S aureus colonization had increased contact with health care, compared with children without colonization. Methicillin-sensitive S aureus nasal colonization ranged from 9% to 31% among practices (mean: 24%). The estimated population prevalence of methicillin-sensitive S aureus was 24.6%. Risk factors associated with methicillin-sensitive S aureus colonization included pet ownership, fingernail biting, and sports participation.. Methicillin-resistant S aureus colonization is widespread among children in our community and includes strains associated with health care-associated and community-acquired infections.

Topics: Adolescent; Biomedical Research; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Female; Humans; Infant; Male; Methicillin Resistance; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Use of active surveillance cultures for methicillin-resistant Staphylococcus aureus (MRSA) for all patients admitted to the intensive care unit has been shown to reduce nosocomial transmission. However, the cost-effectiveness and the utility of implementing use of active surveillance cultures nationwide remain controversial. We sought to develop an artificial neural network (ANN) model that would predict the likelihood of MRSA colonization.. Two acute care hospitals, one in Pittsburgh (hospital A) and one in Kaohsiung, Taiwan (hospital B).. Nasal cultures were performed for all patients admitted to the hospitals. A total of 46 potential risk factors in hospital A and 86 potential risk factors in hospital B associated with MRSA colonization were assessed. Culture results were obtained; 75% of the data were used for training our ANN model, and the remaining 25% were used for validating our ANN model. The culture results were the "gold standard" for determining the accuracy of the model predictions.. The ANN model predictions were accurate 95.2% of the time for hospital A (sensitivity, 94.3%; specificity, 96.0%) and 94.2% of the time for hospital B (sensitivity, 96.6%; specificity, 91.8%), integrating all potential risk factors into the model. Only 17 potential risk factors were needed for the hospital A ANN model (accuracy, 90.9%; sensitivity, 98.5%; specificity, 83.4%), and only 20 potential risk factors were needed for the hospital B ANN model (accuracy, 90.5%; sensitivity, 96.6%; specificity, 84.3%), if the minimal risk factor method was used. Cross-validation analysis showed an average accuracy of 85.6% (sensitivity, 91.3%; specificity, 80.0%).. Our ANN model can be used to predict with an accuracy of more than 90% which patients carry MRSA. The false-negative rates were significantly lower than the false-positive rates in the ANN predictions, which can serve as a safety buffer in case of patient misclassification.

Topics: Algorithms; Carrier State; Hospitals; Humans; Methicillin Resistance; Neural Networks, Computer; Nose; Pennsylvania; Predictive Value of Tests; Risk Factors; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Taiwan

We were presented with a teenage female who developed superior ophthalmic vein thrombosis and cavernous sinus thrombophlebitis after a 1-week history of a single acne-like lesion or furuncle at the anterior tip of the nose. She was managed aggressively with heparin and intravenous antibiotic. Signs and symptoms improved after 2 weeks of treatment, and she was discharged with an anticoagulant.

Topics: Adolescent; Anticoagulants; Cavernous Sinus Thrombosis; Cloxacillin; Disease Progression; Eye; Female; Follow-Up Studies; Furunculosis; Heparin; Humans; Nose; Risk Assessment; Severity of Illness Index; Staphylococcal Infections; Tomography, X-Ray Computed; Treatment Outcome; Veins; Venous Thrombosis

One year prospective study was evaluated to ascertain the prevalence of nasal carriage of potentially pathogenic bacteria in health care workers and the antibiotic susceptibility profile. The bacterial strains were identified by conventional method and the antibiotic resistance was carried out by disc diffusion method. The prevalence of Staphylococcus aureus, coagulase negative staphylococci and methicillin resistant Staphylococcus aureus were 48%, 46% and 14% respectively. The antibiotic susceptibility pattern of these isolates revealed that Staphylococcus aureus were more resistant towards antibiotics than coagulase negative staphylococci. The most effective antibiotic for S. aureus was found to be vancomycin with 100% efficacy, then cephalothin 92%, ciprofloxacin 91%, amikacin 77% and erythromycin 55%, ampicillin 11% and penicillin 3%. Coagulase negative staphylococci were 100% sensitive to vancomycin and cephalothin. Oxacillin showed 78% effectiveness; while ampicillin and penicillin, demonstrated 64% and 59% respectively. Doxycycline (93%), amikacin (93%), fusidic acid (90%) and erythromycin (92%) were effective antimicrobials.

Topics: Anti-Infective Agents; Carrier State; Cross Infection; Disk Diffusion Antimicrobial Tests; Drug Resistance, Bacterial; Hospitals, Pediatric; Humans; Hygiene; Infection Control; Methicillin Resistance; Nose; Personnel, Hospital; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Family; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Intensive Care Units; Methicillin; Methicillin Resistance; Nose; Skin; Staphylococcal Infections; Staphylococcus aureus; Visitors to Patients

Prevalence of hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) infection or colonisation has been associated with antimicrobial consumption. The impact of antibiotic treatment on nasal colonisation is unknown. We conducted a three-month prospective study of 116 patients with extranasal MRSA infection or colonisation, whose nasal MRSA bacterial loads were determined during and after various antibiotic courses over a period of three weeks. Environmental swabs were also taken from the near patient environment. Concomitant nasal MRSA carriage was observed in 76.7% of extranasal MRSA-colonised or -infected patients. The median nasal MRSA bacterial load increased significantly from 2.78 (range 0-6.15) to 5.30 (range 2.90-8.41) log(10) cfu per swab (cfu/swab) (P<0.001) over 21 days during beta-lactam therapy. It also increased from 0 (range 0-4.00) to 4.30 (range 0-7.46) log(10)cfu/swab (P=0.039) over 14 days during fluoroquinolone therapy. Median bacterial loads were significantly higher for beta-lactam- and fluoroquinolone-treated patients on day 7 [4.78, range 0-7.30], day 14 [4.30, range 0-7.60] and day 21 [5.30, range 2.90-8.41] than controls not receiving antibiotics (P<0.05). These loads then decreased by 2-5log(10)cfu/swab 2 weeks after discontinuation of antibiotics. The environment of patients receiving beta-lactam agents (relative risk: 3.55; 95% confidence interval: 1.30-9.62; P=0.018) or fluoroquinolones (4.32; 1.52-12.31; P=0.008) demonstrated more MRSA contamination than the environment around control patients (0.79; 0.67-0.93; P=0.002). Patients on beta-lactam or fluoroquinolone therapy have increased incidence of MRSA colonisation and higher nasal bacterial loads, and appear to spread their MRSA into the near patient environment.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Cluster Analysis; Colony Count, Microbial; Cross Infection; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Environmental Microbiology; Female; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Topics: Animals; Hospitals, Animal; Humans; Incidence; Methicillin Resistance; Nose; Odds Ratio; Orthopedic Procedures; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Veterinarians

Estimates of the prevalence of colonization with methicillin-resistant Staphylococcus aureus (MRSA) vary in HIV-infected patients.. HIV clinic patients were prospectively cultured. Bilateral nasal and axillary swabs were plated on BBL CHROMagar MRSA media. Molecular typing was done by pulse-field gel electrophoresis, and staphylococcal cassette chromosomemec typing was determined. A patient questionnaire was conducted to ascertain potential MRSA risk factors; medical records were reviewed.. Fifteen of 146 (10.3%) patients had MRSA nasal colonization; 1 also had axillary colonization. Twelve of 15 isolates were staphylococcal cassette chromosomemec type IV, and 8 of 14 were USA300 or USA400 genotype. MRSA colonization was associated with lower CD4 cell count, not receiving current or recent antibiotics, history of prior MRSA or methicillin-susceptible Staphylococcus aureus infection (P < 0.05 for all), and a trend toward history of hospitalization or emergency department visit in the past year (P = 0.064). Current use of trimethoprim-sulfamethoxazole was protective for colonization: 0 of 29 trimethoprim-sulfamethoxazole recipients were colonized versus 15 of 117 nonrecipients, P = 0.04. In a multivariate logistic regression model, prior infection with either methicillin-susceptible S. aureus (odds ratio = 32.4, 95% confidence interval 3.04 to 345.42) or MRSA (odds ratio = 9.71, 95% confidence interval 2.20 to 43.01), not receiving current or recent antibiotics (odds ratio = 0.026, 95% confidence interval 0.002 to 0.412), and lower CD4 count (odds ratio 0.996, 95% confidence interval 0.992 to 0.999) were associated with MRSA colonization.. The prevalence of MRSA nasal colonization was relatively high compared with prior studies; axillary colonization was rare. Prior staphylococcal infection (methicillin-susceptible S. aureus or MRSA), not receiving antibiotics, and lower CD4 count were associated with MRSA nasal colonization. Trimethoprim-sulfamethoxazole seemed to be protective of MRSA colonization.

Topics: Adult; Aged; Anti-Bacterial Agents; Female; HIV; HIV Infections; Humans; Male; Methicillin; Methicillin Resistance; Middle Aged; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Serial nasal swabs were collected at the ages of 1.5, 6, and 14 months from 443 infants in the Generation R Study. The objective was to study the dynamics and determinants of Staphylococcus aureus nasal carriage in the first year of life. The prevalence of S. aureus carriage decreased in the first year of life, from 52.1% at the age of 1.5 months to 12.9% at 14 months. Persistent carriage, defined as continuous carriage of the same S. aureus strain at the three sampling moments, was rarely detected in early infancy.

Topics: Age Factors; Carrier State; Female; Humans; Infant; Infant, Newborn; Male; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determine the nasal carriage rate of S. aureus and MRSA strains in Turkish elementary school children. We also analyzed molecular characterizations of MRSA strains by using pulse field gel electrophoresis (PFGE), multi locus sequence typing (MLST), staphylococcal chromosomal cassette mec (SCCmec) typing, and detection of the Panton-valentine leucocidin (PVL) gene. The nasal swabs were obtained from 4,050 children during a 4 month period in Ankara. In vitro antimicrobial susceptibility testing to 1 mug oxacillin and 30 mug cefoxitin was determined by a disk diffusion method. We found that the 1,001 of 4,050 (24.7%) children were colonized with S. aureus. Three S. aureus strains were resistant to oxacillin and cefoxitin. The rate of MRSA among all children was 0.07%. The MRSA strains revealed three different PFGE pattern. All MRSA isolates by harbored the SCCmec type IV element, but not the PVL gene. The two MRSA isolate belonged to sequence type (ST) 30, whereas the other one was a unique type. The results of this study demonstrated that S. aureus nasal carriage rate was consistent with previous studies. However, MRSA carriage rate was low. This study also indicated that the ST30-type IV without PVL gene MRSA clone may be expected to spread in Turkish community.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacterial Typing Techniques; Carrier State; Child; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Leukocidins; Male; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus; Turkey

Topics: Carrier State; Community-Acquired Infections; Humans; Malaysia; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Staphylococcal Infections; Staphylococcus aureus

Mutations in the staphylococcal virulence regulator gene agr frequently occur during Staphylococcus aureus infection. Whether agr-defective strains are fit for colonization, an important prerequisite for infection, is unknown. Screening by means of assays to detect delta-hemolysin activity and agr autoinducing peptide production indicated that 15 ( approximately 9%) of 160 healthy human subjects were colonized with an agr-defective strain or a mixture of agr-positive and -defective S. aureus strains. The presence of identical agr-defective strains in family members suggests that these strains are transmissible. Additionally, carriage of an agr-defective strain was associated with hospitalization, raising the possibility that such strains may be selected in a nosocomial setting.

Topics: Adult; Bacterial Proteins; Carrier State; Child, Preschool; Female; Gene Expression Regulation, Bacterial; Hemolysin Proteins; Humans; Male; Mutation; Nose; Peptides, Cyclic; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Trans-Activators

Patients in long-term acute care (LTAC) facilities often have many known risk factors for acquisition of antibiotic-resistant bacteria. However, the prevalence of resistance in these facilities has not been well described.. We performed a single-day, point-prevalence study of a 180-bed, university-affiliated LTAC facility in Baltimore to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii in the anterior nares, perirectal area, sputum, and wounds.. Among the 147 patients evaluated, we found a high prevalence of colonization by both MRSA (28%) and A baumannii (30%). Of the A baumannii isolates, 90% were susceptible to imipenem and 92% were susceptible to ampicillin-sulbactam. No isolates were resistant to both imipenem and ampicillin-sulbactam.. The high prevalence of resistance found in this study supports the need for increased surveillance of patients in the LTAC environment. The fact that these patients are often frequently transferred to tertiary care facilities also supports the need for coordination and collaboration among facilities within the same health care system and the broader geographic area.

Topics: Academic Medical Centers; Acinetobacter baumannii; Acinetobacter Infections; Adult; Aged; Anal Canal; Anti-Bacterial Agents; Baltimore; Cross Infection; Female; Humans; Intensive Care Units; Long-Term Care; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Wounds and Injuries

OBJECTIVE. To determine the prevalence of Staphylococcus aureus strains among hospitalized patients at the beginning of their hospitalization and during their treatment and the resistance of strains to antibiotics, and to evaluate epidemiologic characteristics of these strains. PATIENTS AND METHODS. Sixty-one patients treated at the Department of Cardiac, Thoracic and Vascular Surgery were examined. Identification of Staphylococcus aureus strains was performed using plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, beta-lactamase production, phagotypes, and phagogroups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 microg per disk and oxacillin 1 microg per disk). RESULTS. A total of 297 Staphylococcus aureus strains were isolated. On the first day of hospitalization, the prevalence rate of Staphylococcus aureus strains among patients was 67.3%, and it statistically significantly increased to 91.8% on days 7-10 of hospitalization (P<0.05). During hospitalization, patients were colonized with Staphylococcus aureus strains resistant to cephalothin (17.6% of patients, P<0.05), cefazolin (14.6%, P<0.05), tetracycline (15.0%, P<0.05), gentamicin (37.7%, P<0.001), doxycycline (30.7%, P<0.001), and tobramycin (10.6%, P>0.05). Three patients (4.9%) were colonized with methicillin-resistant Staphylococcus aureus strains, belonging to phage group II phage type 3A and phage group III phage types 83A and 77; 22.6-25.5% of Staphylococcus aureus strains were nontypable. During hospitalization, the prevalence rate of phage group II Staphylococcus aureus strains decreased from 39.6% to 5.7% (P<0.05) and the prevalence rate of phage group III Staphylococcus aureus strains increased to 29.5% (P<0.001). CONCLUSIONS. Although our understanding of Staphylococcus aureus is increasing, well-designed community-based studies with adequate risk factor analysis are required to elucidate further the epidemiology of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Surveillance of methicillin-resistant Staphylococcus aureus provides relevant information on the extent of the methicillin-resistant Staphylococcus aureus epidemic, identifies priorities for infection control and the need for adjustments in antimicrobial drug policy, and guides intervention programs.

Topics: Anti-Bacterial Agents; Bacteriophage Typing; Cross-Sectional Studies; Data Interpretation, Statistical; Drug Resistance, Multiple, Bacterial; Hospitalization; Humans; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Nose; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Time Factors

An increasing number of infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carrying the Panton-Valentine leukocidin (PVL) genes was recently identified in Greece. In the present study, 170 patients with S. aureus infections and 123 uninfected children (<15 years old) who had been tested for nasal carriage were evaluated during a 2-year period. The MecA, PVL and superantigen family genes, and MRSA clones, were investigated by molecular methods. Sites of infection and laboratory findings for patients were recorded. The results were compared and statistically analysed. Among 123 uninfected children 73 (59%) carried S. aureus, including four MRSA strains. Of these, three MRSA and three methicillin-sensitive S. aureus (MSSA) strains were PVL-positive (p <0.0001). Ninety-six patients (96/170) exhibited skin and soft-tissue infections (SSTIs), and 74 exhibited invasive infections. The incidence of staphylococcal infections increased during July to September each year. In total, 110 S. aureus isolates were PVL-positive (81 from SSTIs and 29 from invasive infections, p <0.0001). Ninety-nine out of 106 MRSA (93%) isolates from 170 patients carried the PVL genes (p <0.0001); 97 belonged to the clonal complex CC80. Leukocyte and polymorphonuclear cell counts were higher among children with MRSA infections (p <0.005). MSSA predominated among patients with invasive infections (43/74), and carried mainly genes of the superantigen family. Children <5 years of age showed a higher risk of MRSA infection. The present study demonstrates that infections due to PVL-positive CA-MRSA spread easily among children, and SSTIs can lead to invasive infections. Nasal colonization may be an additional factor contributing to the emergence of CA-MRSA.

Topics: Bacterial Proteins; Bacterial Toxins; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Exotoxins; Female; Greece; Humans; Incidence; Infant; Leukocidins; Male; Methicillin Resistance; Nose; Penicillin-Binding Proteins; Seasons; Staphylococcal Infections; Staphylococcus aureus; Superantigens

The prevalence of methicillin-resistant Staphylococcus aureus nasal carriage among 959 healthy employees of the Hellenic Air Force was investigated from November 2004 to October 2005. Nine participants were found to be colonised by methicillin-resistant Staphylococcus aureus (MRSA) (SCCmec type IV). Eight of the MRSA isolates were PVL-negative and belonged to ST30 by MLST, while the remaining one isolate was PVL-positive and classified as ST-80.

Topics: Adolescent; Adult; Carrier State; Female; Greece; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Military Personnel; Nasal Mucosa; Nose; Staphylococcal Infections

A new chromogenic medium, denim blue (DB), was compared with methicillin-resistant Staphylococcus aureus (MRSA) Select (MRSAS) for detection of MRSA from surveillance specimens. On DB, MRSA colonies are larger (0.57-0.8 versus 0.45-0.6 mm at 18 and 24 h, respectively). Despite this, sensitivities of DB were 77% and 96% at 18 and 24 h, respectively, and those of MRSAS were 63% and 97.5%. Specificities were significantly higher for MRSAS than DB. The study demonstrates that DB and MRSA are equal for the detection of MRSA from surveillance specimens provided the plates are read after 24 h of incubation. Positive predictive values of both media were less than 95% requiring confirmation of MRSA, by another method, from all new patients.

Topics: Anal Canal; Bacteriological Techniques; Carrier State; Chromogenic Compounds; Culture Media; Humans; Methicillin Resistance; Nose; Predictive Value of Tests; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

Pig farmers and veterinarians in contact with livestock in The Netherlands have a higher risk of methicillin-resistant Staphylococcus aureus (MRSA) carriage than the general population. The objective of this study was to investigate whether this is also true for other professionals in contact with pigs in an international setting. A convenience sample of 272 participants at an international conference on pig health in Denmark was screened for MRSA carriage using combined nose/throat swabs and were asked to complete a questionnaire concerning animal contacts, exposure to known MRSA risk-factors, and the protective measures taken when entering pig farms. In total, 34 (12.5%) participants from nine countries carried MRSA. Thirty-one of these isolates were non-typeable by pulsed-field gel electrophoresis following SmaI digestion of chromosomal DNA. All of the non-typeable isolates belonged to spa types (t011, t034, t108, t571, t567 and t899) that correspond to multilocus sequence type 398. All of the above-mentioned spa types, with the exception of t899, have been isolated previously from either Dutch pigs, pig farmers and/or veterinarians. Protective measures, e.g., masks, gowns and gloves, did not protect against MRSA acquisition. Transmission of MRSA from pigs to staff tending to these animals appears to be an international problem, creating a new reservoir for community-acquired MRSA (CA-MRSA) in humans in Europe, and possibly worldwide. The rise of a new zoonotic source of MRSA could have a severe impact on the epidemiology of CA-MRSA, and may have consequences for the control of MRSA, especially in those countries that maintain a low prevalence by means of search-and-destroy policies.

Topics: Adult; Aged; Animals; Bacterial Typing Techniques; Carrier State; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Pharynx; Polymorphism, Restriction Fragment Length; Prevalence; Staphylococcal Infections; Staphylococcal Protein A; Staphylococcus aureus; Surveys and Questionnaires; Veterinarians; Zoonoses

We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay with the CHROMagar MRSA assay for the detection of MRSA in 286 nasal surveillance specimens. Compared with the CHROMagar MRSA assay, PCR had sensitivity, specificity, positive predictive value, and negative predictive values of 100%, 98.6%, 95.8%, and 100%, respectively. The mean PCR turnaround time was 14.5 h.

Topics: Bacteriological Techniques; Carrier State; Culture Media; Hospitals, Teaching; Humans; Methicillin Resistance; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Time Factors

This study aimed to establish the feasibility and cost-effectiveness of rapid molecular screening for hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) in surgical patients within a teaching hospital.. In 2006, nasal swabs were obtained before surgery from all patients undergoing elective and emergency procedures, and screened for MRSA using a rapid molecular technique. MRSA-positive patients were started on suppression therapy of mupirocin nasal ointment (2 per cent) and undiluted chlorhexidine gluconate bodywash.. A total of 18,810 samples were processed, of which 850 (4.5 per cent) were MRSA positive. In comparison to the annual mean for the preceding 6 years, MRSA bacteraemia fell by 38.5 per cent (P < 0.001), and MRSA wound isolates fell by 12.7 per cent (P = 0.031). The reduction in MRSA bacteraemia and wound infection was equivalent to a saving of 3.78 beds per year (276,220 pounds sterling), compared with the annual mean for the preceding 6 years. The cost of screening was 302,500 pounds sterling, making a net loss of 26,280 pounds sterling. Compared with 2005, however, there was a net saving of 545,486 pounds sterling.. Rapid MRSA screening of all surgical admissions resulted in a significant reduction in staphylococcal bacteraemia during the screening period, although a causal link cannot be established.

Topics: Bacteremia; Cost-Benefit Analysis; Cross Infection; Elective Surgical Procedures; Emergency Treatment; Humans; Methicillin Resistance; Nose; Patient Compliance; Polymerase Chain Reaction; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus; Surgery Department, Hospital; Surgical Wound Infection

We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus.

Topics: Adult; Aged; Aged, 80 and over; Bacteriological Techniques; Baltimore; Carrier State; Culture Media; False Positive Reactions; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Polymerase Chain Reaction; Prisons; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

To evaluate the economic impact of performing rapid testing for Staphylococcus aureus colonization before admission for all inpatients who are scheduled to undergo elective surgery and providing subsequent decolonization therapy for those patients found to be colonized with S. aureus.. A budget impact model that used probabilistic sensitivity analysis to account for the uncertainties in the input variables was developed. Primary input variables included the marginal effect of S. aureus infection on patient outcomes among patients who underwent elective surgery, patient demographic characteristics, the prevalence of nasal carriage of S. aureus, the sensitivity and specificity of the rapid diagnostic test for S. aureus colonization, the efficacy of decolonization therapy for nasal carriage of S. aureus, and cost data. Data sources for the input variables included the 2003 Nationwide Inpatient Sample data and the published literature.. In 2003, there were an estimated 7,181,484 patients admitted to US hospitals for elective surgery. Our analysis indicated preadmission testing and subsequent decolonization therapy for patients colonized with S. aureus would have produced a mean annual cost savings to US hospitals of $231,538,400 (95% confidence interval [CI], -$300 million to $1.3 billion). The mean annual number of hospital-days that could have been eliminated was estimated at 364,919 days (95% CI, 67,893-926,983 days), and a mean of 935 in-hospital deaths (95% CI, 88-3,691) could have been avoided per year. Sensitivity analysis indicated a 64.5% probability that there would be cost savings to US hospitals as a result of preadmission testing and subsequent decolonization therapy.. The addition of preadmission testing and decolonization therapy to standard care would result in significant cost savings, even after accounting for variations in the model input values.

Topics: Budgets; Carrier State; Cost-Benefit Analysis; Economics, Hospital; Elective Surgical Procedures; Female; Hospital Mortality; Humans; Male; Mass Screening; Middle Aged; Nose; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

A commercial rapid polymerase chain reaction methicillin-resistant Staphylococcus aureus (MRSA) screening method (IDI-MRSA) is validated for the use with nasal swabs transported in liquid Stuart's medium. We investigated the use of IDI-MRSA for screening for MRSA in pooled nose, axilla, and groin swabs and in single swabs from skin puncture sites, wounds, throat, rectum, and groin using swabs transported in Amies medium without charcoal. We performed the IDI-MRSA test on swabs that had been used for routine MRSA broth culture and which were selected to be about 50% MRSA positive. We compared the IDI-MRSA result with the MRSA culture result. With 201 pooled sets, the sensitivity of IDI-MRSA was 85% and the specificity 95%. With 32 single screening swabs, sensitivity was 94% and specificity 80%. The method is not compromised by swab transport in Amies medium if an additional heating step is used. We had a low rate of initial inhibition (1.3%), which may have been due to the extra heating step used to liquefy gel from the Amies medium. Thus, in this study IDI-MRSA gives similar results to culture with pooled or single swabs from multiple screening sites.

Topics: Axilla; Bacteriological Techniques; Carrier State; DNA, Bacterial; Groin; Humans; Methicillin Resistance; Nose; Polymerase Chain Reaction; Sensitivity and Specificity; Skin; Staphylococcal Infections; Staphylococcus aureus

International epidemiological studies have shown that clinical isolates of Staphylococcus aureus are usually capsulated with either type 5 or 8 capsular polysaccharides (CPs). Because all noncapsulated strains were found to be cross-reactive with polysaccharide 336 (336PS) antibodies, the noncapsulated strains were denoted as type 336PS. The capsular types of 162 Dutch methicillin-susceptible S. aureus strains derived from individuals living in the Rotterdam area were determined. The serotype distribution was 28.4% serotype 5, 53.7% type 8, and 17.9% type 336PS. Serotyping was in agreement with genotyping by amplified fragment length polymorphism (AFLP) and multi locus sequence typing (MLST). Among 49 nasal carriage isolates from healthy children 24.5% belonged to serotype 5, 67.3% were type 8 and 8.2% were type 336PS. For 28 adult patients on chronic ambulatory peritoneal dialysis (CAPD) the serotype incidences among carriage isolates obtained from the nose, catheter exit-site, and abdominal skin were 45.1%, 41.2% and 13.7%, respectively. Among S. aureus strains deriving from blood cultures, the serotype incidences were 17.7% serotype 5, 53.2% type 8, and 29.0% type 336PS. Apparently, type 336PS strains are more prevalent (P=0.017) among bacteraemia isolates as compared with the nasal carriage isolates obtained from healthy children and CAPD patients. In conclusion, all Dutch S. aureus isolates belonged to types 5, 8, or 336PS, which is in agreement with data from other countries. Thus, addition of the 336PS conjugate to a type 5- and type 8-CP protein conjugate vaccine would significantly extend the vaccine coverage.

Topics: Amplified Fragment Length Polymorphism Analysis; Bacterial Capsules; Carrier State; Cluster Analysis; DNA, Bacterial; Genotype; Humans; Incidence; Netherlands; Nose; Sequence Analysis, DNA; Serotyping; Staphylococcal Infections; Staphylococcus aureus

To evaluate the prevalence of Staphylococcus aureus carriage among healthy preschool children in our region, nasal swabs were collected from 5- to 7-year-old healthy children who were attending a day care center. Sociodemographic features and the data related with risk factors were obtained from the children's parents. Of the 200 children, S. aureus was isolated in 36 (18%) subjects. Methicillin-resistant S. aureus was isolated in 2 (5.6%) of these subjects, neither of whom had any identified risk factors. Antimicrobial susceptibility testing revealed that all tested strains were sensitive to gentamicin, vancomycin, trimethoprim-sulfamethoxazole, rifampicin, and mupirocin. Erythromycin, clindamycin, fusidic acid, and tetracycline resistance were determined to be 16.6, 8.3, 5.6, and 8.3%, respectively.

Topics: Anti-Bacterial Agents; Carrier State; Child; Child Day Care Centers; Child, Preschool; Community-Acquired Infections; Drug Resistance, Bacterial; Female; Humans; Male; Methicillin Resistance; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Turkey

There are two important routes for the transmission of Staphylococcus aureus to the burn wound. In the endogenous route, patients naturally carrying S. aureus colonize their own wounds, whereas in the exogenous route burn wounds are cross-infected from other sources. In this study we evaluated the effect of blocking the endogenous route on S. aureus burn wound colonization by mupirocin application in the nose of patients at the time of admission.. From September 2000 to January 2002 all patients with burns admitted to a single dedicated Burn Centre received nasal mupirocin upon admission. This period was compared to two control periods (C1: July 1999 to July 2000 and C2: January 2002 to January 2003) for S. aureus burn wound colonization. The colonization risk was analysed, adjusting for confounding, with Cox proportional hazard regression.. A total of 98 patients did not have S. aureus burn wound colonization at the time of admission and were, thus, considered at risk for S. aureus acquisition during their stay. As compared to C1, the relative risk of acquiring S. aureus in their wound was 0.48 (95% CI: 0.24-0.97) in the mupirocin period and 0.55 (95% CI: 0.28-1.1) during the C2 period. S. aureus nasal/pharyngeal colonization was a significant independent risk factor for wound colonization (RR: 2.3; 95% CI: 1.2-4.2).. Nasal mupirocin may contribute to risk reduction of S. aureus wound colonization in patients with burns.

Topics: Administration, Intranasal; Adult; Anti-Bacterial Agents; Burns; Cross Infection; Drug Administration Routes; Female; Humans; Male; Mupirocin; Nasal Mucosa; Nose; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

It has been shown that persistent Staphylococcus aureus nasal carriage results in increased bacterial dispersal and a higher risk of infection compared to non-or-intermittent S. aureus carriage. Although many studies investigated S. aureus nasal carriage in HIV patients, none compared persistent carriage to non-persistent carriage nor were studies performed in the HAART era. We investigated the host-microbe interplay of persistent S. aureus nasal carriage in HIV-infected patients by studying host determinants of persistent carriage as well as the genetic structure of S. aureus strains isolated. We compared this genetic structure with the previously determined population structure of S. aureus isolates obtained from healthy individuals. Between February 2004 and June 2005 all HIV patients visiting the outpatient department of Erasmus MC (Rotterdam, The Netherlands) were asked to participate in this study. Participants were interviewed and screened for persistent S. aureus carriage using two semi-quantitative nasal swab cultures. For 443 patients two cultures were available, 131 (29.6%) were persistent carriers, which is significantly higher as compared to healthy individuals from the same geographic region (17.6%; P<0.0001). Male sex (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.32-3.73), current smoking (OR, 0.58; 95% CI, 0.38-0.90), Pneumocystis jiroveci pneumonia (PCP) prophylaxis (OR, 0.39; 95% CI, 0.16-0.97) and antiretroviral therapy (OR, 0.61; 95% CI, 0.38-0.98) were independent determinants of persistent carriage. Only two strains were mecA positive (1.2%) and no PVL positive strains were detected. The population structure of S. aureus strains isolated from HIV patients appeared to be strongly overlapping with that of S. aureus isolates from healthy individuals.

Topics: Adult; Aged; Ambulatory Care; Amplified Fragment Length Polymorphism Analysis; Anti-HIV Agents; Bacterial Proteins; Bacterial Toxins; Carrier State; Chemoprevention; Cluster Analysis; DNA, Bacterial; Exotoxins; Female; HIV Infections; Humans; Leukocidins; Male; Middle Aged; Netherlands; Nose; Penicillin-Binding Proteins; Pneumonia, Pneumocystis; Risk Factors; Sex Factors; Smoking; Staphylococcal Infections; Staphylococcus aureus

Topics: Carrier State; Humans; Intensive Care Units; Methicillin Resistance; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

Forty-eight Staphylococcus aureus isolates collected from a young, healthy, Irish university student population from 1995 to 2004 were screened for 16 enterotoxin (SE) and enterotoxin-like (SEl) genes (sea-see, seg-sei, selj-selo, selq, selu), and for the toxic shock toxin syndrome toxin-1 gene, tst. All of the isolates harboured at least one SE or SEl gene and 66.7 % possessed a classical SE gene (sea, seb, sec), the commonest being the seb gene. Most of the isolates (85.4 %) had a complete egc locus (selo, selm, sei, seln, seg). The intergenic sei-seln region of the egc locus was typed by PCR-RFLP in 34 isolates, 15 possessing pseudogenes psient1 and psient2 and 19 having the selu gene. The seh and sell genes, the selk-selq gene combination, and the tst gene were each found in <15 % of isolates. The agr genotype distribution was agr type III, 37.5 %; agr type I, 35.4 %; agr type II, 25 %; and agr type IV, 2.1 %. There was no association between SE-SEl genotype and agr type. All tst gene-positive isolates were of agr type III and harboured a classical SE gene. Multiple locus, variable number tandem repeat analysis (MLVA) produced 47 different patterns. While the sdr locus was present in all isolates, half of them lacked one or two of the sdr gene amplimers. Twenty isolates harboured the bbp gene, its presence being associated with agr type III, but not with the SE-SEl gene profile. The agr types of isolates were associated with MLVA subclusters. Selective MLST analysis revealed seven novel sequence types and a new aroE allele. Five clonal clusters (CCs), including CCs comprising major pandemic clones CC30, CC5 and CC22 and minor lineages CC6 and CC9, and three singletons were identified.

Topics: Adolescent; Adult; Bacterial Proteins; Bacterial Toxins; Carrier State; DNA, Bacterial; Enterotoxins; Humans; Ireland; Minisatellite Repeats; Nose; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Staphylococcal Infections; Staphylococcus aureus; Students; Superantigens; Trans-Activators; Universities

Staphylococcus aureus nasal colonization is a well-known risk factor for development of S.aureus infections in humans, but despite this established association, we are only beginning to understand the factors, both host and pathogen, that play a role in the colonization of the nares by S. aureus. The cotton rat is a model for many human respiratory pathogens and has proved its utility as a robust model for S. aureus nasal colonization. In this animal model, S. aureus is instilled in the nostrils of adult cotton rats, the bacteria rapidly colonize, and 7 days later S. aureus nasal colonization is enumerated by surgical removal of the nose and recovery of the colonizing S. aureus. This model is an excellent animal model to allow for the evaluation of the efficacy of various therapies, including semi-solid formulations, for determination of their ability to eradicate S. aureus nasal colonization. Further, the cotton rat model allows for assessment of the ability of defined genetic mutants of S. aureus to colonize mucosal surfaces. Finally, this model has demonstrated its utility for the assessment of various antigens as vaccine candidates to protect against S. aureus nasal colonization. This chapter will discuss in detail the method to establish nasal colonization, treatment and eradication of colonization, and recovery of the colonizing bacteria from the nose.

Topics: Animals; Disease Models, Animal; Humans; Nose; Rats; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Topics: Carrier State; Humans; Infection Control; Ireland; Methicillin Resistance; Nose; Physicians, Family; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus sequence type 398 (ST398 MRSA) was identified in Dutch pigs and pig farmers. ST398 methicillin-susceptible S. aureus circulates among humans at low frequency (0.2%) but was isolated in 3 human cases of bacteremia (2.1%; p = 0.026). Although its natural host is probably porcine, ST398 MRSA likely causes infections in humans.

Topics: Animals; Anti-Bacterial Agents; Carrier State; Humans; Methicillin; Methicillin Resistance; Netherlands; Nose; Occupational Exposure; Staphylococcal Infections; Staphylococcus aureus; Swine

Staphylococcus aureus nasal carriage in HIV patients remains incompletely characterized. The aim of the present study was to describe epidemiologic and molecular features of S. aureus nasal colonization in HIV outpatients.. HIV outpatients with no history of hospitalization within the previous 2 years were screened for S aureus nasal colonization. Three samples were collected from each patient, and the risk factors for colonization were assessed. Nasal carriage was classified as persistent colonization, transient colonization, or no colonization. Persistent colonization was subdivided into simple (same DNA profile) or multiple (different DNA profiles) using pulsed-field gel electrophoresis (PFGE) for genotyping the strains of S. aureus.. A total of 111 patients were evaluated, of which 70 (63.1%) had at least 1 positive culture for S aureus. Patients in clinical stages of AIDS were more likely to be colonized than non-AIDS patients (P = .02). Among the patients with S aureus nasal carriage, 25.2% were transient carriers and 39.4% were persistent carriers. PFGE analysis showed that the persistent colonization was simple in 24 patients and multiple in 17 patients.. The HIV patients had a high rate of S. aureus nasal colonization. The most common characteristic of colonization was simple persistent colonization showing the same genomic profile.

Topics: Adult; Carrier State; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; HIV Infections; Humans; Male; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is an important human pathogen, but it appears more commonly in asymptomatic colonization of the nasopharynx than in cases of invasive disease. Evidence concerning the global population structure of S. aureus is limited by the overrepresentation in the multilocus sequence testing database of disease isolates recovered from Western Europe, the Americas, Australia, and Japan. We address this by presenting data from the S. aureus carriage population in Mali, the first detailed characterization of asymptomatic carriage from an African population. These data confirm the pandemic spread of many of the common S. aureus clones in the carriage population. We also note the high frequency (approximately 24%) of a single divergent genotype, sequence type 152 (ST152), which has not previously been recovered from nasal carriage isolates but corresponds to a sporadic Panton-Valentine leukocidin (PVL)-positive, community-acquired methicillin-resistant S. aureus clone noted mostly in Central Europe. We show that 100% of the ST152 isolates recovered from nasal carriage samples in Mali are PVL positive and discuss implications relating to the emergence and spread of this virulent genotype.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Toxins; Carrier State; Disease Outbreaks; Exotoxins; Female; Genotype; Humans; Leukocidins; Male; Mali; Middle Aged; Nose; Nucleic Acid Amplification Techniques; Phylogeny; Staphylococcal Infections; Staphylococcus aureus; Virulence

Staphylococcus aureus is a common cause of infection, particularly in persons colonized by this organism. Virulent strains of methicillin-resistant S. aureus (MRSA) have emerged in the general community.. A nationally representative survey of nasal colonization with S. aureus was conducted from 2001 through 2004 as part of the National Health and Nutrition Examination Survey. MRSA isolates were identified by the oxacillin disk-diffusion method. The pulsed-field gel electrophoresis (PFGE) type was determined for all MRSA isolates. A t statistic was used to compare the prevalence of colonization across biennia and across population subgroups. Cofactors independently associated with colonization were determined with backward stepwise logistic modeling.. The prevalence of colonization with S. aureus decreased from 32.4% in 2001-2002 to 28.6% in 2003-2004 (P < .01), whereas the prevalence of colonization with MRSA increased from 0.8% to 1.5% (P < .05). Colonization with MRSA was independently associated with healthcare exposure in males and with having been born in the United States, age > or =60 years, diabetes, and poverty in females. In 2003-2004, a total of 19.7% (95% confidence interval, 12.4%-28.8%) of MRSA-colonized persons carried a PFGE type associated with community transmission.. Nasal colonization with MRSA has increased in the United States, despite an overall decrease in nasal colonization with S. aureus. PFGE types associated with community transmission only partially account for the increase in MRSA colonization.

Topics: Adolescent; Adult; Aged; Carrier State; Child; Child, Preschool; Data Collection; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Infant; Male; Methicillin Resistance; Middle Aged; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; United States

Staphylococcus aureus is capable of persistently colonizing the vestibulum nasi. We hypothesized that polymorphisms in host inflammatory response genes and genetic variation in S. aureus contribute to susceptibility to S. aureus carriage and infection.. The prevalence of persistent nasal carriage of S. aureus in 3851 participants aged 61-101 years was 18% (678 of 3851 participants), whereas 73% of volunteers (2804 of 3851) were not colonized. A total of 1270 individuals had boils. Polymorphisms in TNFA (C -863T), IL4 (C -542T), CFH (Tyr402His), and CRP (C1184T, C2042T, and C2911G) were determined. Genetic similarity among 428 S. aureus isolates was determined by use of amplified fragment length polymorphism analysis (AFLP)-mediated genotyping.. The IL4 -524 C/C host genotype was associated with an increased risk of persistent S. aureus carriage, irrespective of S. aureus AFLP genotype. The CRP haplotype 1184C; 2042C; 2911C was overrepresented in individuals who were not colonized . In individuals with boils, carriers of the CFH Tyr402 variant, and the CRP 2911 C/C genotype were overrepresented.. Persistent carriage of S. aureus is influenced by genetic variation in host inflammatory response genes. As would be expected in multifactorial host-microbe interactions, these effects are limited. Interestingly, host genotype was associated with the carriage of certain S. aureus genotypes. Apparently, a close interaction between host and bacterial determinants are prerequisites for long-term colonization.

Topics: C-Reactive Protein; Carrier State; Cohort Studies; Complement Factor H; DNA; Furunculosis; Humans; Interleukin-4; Nose; Polymorphism, Genetic; Staphylococcal Infections; Staphylococcus aureus

The aim of this study is to determine the rate of nasal carriage of Staphylococcus aureus (NCSA) in children with allergic rhinitis (AR) and to determine the effect of intranasal fluticasone propionate spray on the NCSA.. Nasal swabs were taken from the children admitted to general pediatrics and pediatric pulmonology clinics. Patients were divided into two groups according to the presence or absence of AR. Diagnosis of AR was based on the patient's symptoms. Nasal swabs were taken from AR patients before and after the treatment with intranasal fluticasone propionate, and from the control group at the beginning and after 2 months.. Whole NCSA rate was 17.9%; it was 21.4% for AR patients and 15.9% for control group, respectively (p>0.05). Treatment with intranasal fluticasone propionate spray did not influence NCSA in AR patients.. It seemed that NCSA was not increased in children with AR and treatment with intranasal fluticasone propionate spray did not change NCSA in AR patients. It is obvious that better understanding of the factors affecting the acquisition and loss of NCSA might increase our knowledge about the relationship between NCSA, allergic airway diseases and their treatments.

Topics: Administration, Intranasal; Androstadienes; Anti-Allergic Agents; Carrier State; Child; Child, Preschool; Female; Fluticasone; Humans; Male; Nose; Prevalence; Rhinitis, Allergic, Seasonal; Staphylococcal Infections; Staphylococcus aureus

To determine if children adopted to Swedish families from countries with a high carrier rate of methicillin-resistant Staphylococcus aureus (MRSA) are infected or colonized with MRSA.. From January 2000 to May 2005, 23 adopted children from 6 countries were examined for MRSA at the University hospital in Lund after their arrival in Sweden.. Thirteen of the 23 children (57%) were MRSA positive with a median age of the children at the time MRSA was detected of 6 (range 3-16) months. All MRSA positive children had a history of hospitalization in their native country before arriving in Sweden. The throat was the most frequent and persistent site where MRSA was seen while in sites such as the anterior nares and perineum, MRSA was found more intermittently. The MRSA-positive children were adopted into 13 Swedish families and in 3 families, 6 of 10 family members became MRSA positive.. Children adopted from foreign countries to Swedish families and with a history of hospitalization in their native country were commonly colonized with MRSA. The throat was the most frequent site colonized and transmission of MRSA from adopted children to other family members occurred.

Topics: Adoption; Carrier State; China; Colombia; Emigration and Immigration; Female; Humans; Infant; Korea; Male; Mass Screening; Methicillin Resistance; Nose; Perineum; Pharynx; Poland; Staphylococcal Infections; Staphylococcus aureus; Sweden

Screening for nasal colonization is an important aspect of many methicillin-resistant Staphylococcus aureus (MRSA) control programs. Real-time polymerase chain reaction (RT-PCR) is an attractive alternative to standard culture techniques because of the considerably shorter turnaround time. An assay has been validated for diagnostic purposes in humans, however this methodology has not been evaluated in horses. The purpose of this study was to compare an RT-PCR assay for rapid identification of MRSA directly from nasal swabs in horses to standard culture techniques. Nasal swabs collected from 293 horses were processed using a commercial RT-PCR assay (IDI-MRSA, GeneOhm Sciences, San Diego, CA) according to the manufacturer's instructions. The swabs were also cultured and MRSA was identified according to standard protocols. Initially only 176/293 samples yielded valid PCR results. Two of 176 and 167/176 samples were positive and negative, respectively, by both PCR and culture. Seven of 176 samples were positive by PCR and negative by culture, whereas 0/176 samples were negative by PCR and positive by culture. The kappa statistic was 0.35, which represented poor agreement between the tests. Of the remaining 117 samples, 105 samples were initially reported as "unresolved". Following one freeze-thaw cycle of the lysates, the recommended technique to resolve such samples, 61/110 (55%) samples remained unresolved. In this study, the IDI-MRSA assay was not a clinically practical screening test for horses harbouring nasal MRSA. Its agreement with culture was poor and the high unresolved rate (37%) also significantly decreased the clinical utility of the test.

Topics: Animals; Bacteriological Techniques; Carrier State; Horse Diseases; Horses; Methicillin Resistance; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus

Rapid and reliable detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers is crucial for the effective control of MRSA transmission in healthcare facilities. The aim of this study was to verify the performance of the IDI-MRSA real-time PCR assay for direct MRSA detection in diverse mucocutaneous swabs from hospitalized patients. Swabs from nares (n = 522) and skin or other superficial sites (n = 478) were prospectively collected for MRSA screening from 466 patients admitted to an 858-bed teaching hospital. Swabs were inoculated onto selective chromogenic MRSA-ID agar, buffer extraction solution for IDI-MRSA assay, and enrichment broth. MRSA was detected by culture in 100 specimens from 47 patients. Compared to enrichment culture, the sensitivity and specificity of the PCR assay were 81.0 and 97.0%, respectively, and its positive and negative predictive values were 75.0 and 97.9%, respectively. The IDI-MRSA assay was more sensitive on swabs from nares (90.6%) than from other body sites (76.5%, P < 0.01). The PCR assay detected MRSA in 42 of 47 patients with culture positive study samples. Of 26 patients with culture-negative but PCR-positive study samples, 11 were probable true MRSA carriers based on patient history and/or positive culture on a new sample. The median turnaround time for PCR results was 19 h versus 3 days for agar culture results and 6 days for enrichment culture results. These data confirm the value of IDI-MRSA assay for rapid screening of MRSA mucocutaneous carriage among hospitalized patients. Cost-effectiveness studies are warranted to evaluate the impact of this assay on infection control procedures in healthcare settings.

Topics: Bacteriological Techniques; Carrier State; Culture Techniques; Hospitals, University; Humans; Methicillin Resistance; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Skin; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Time Factors

Peristomal infection is the most common complication of percutaneous endoscopic gastrostomy (PEG) insertion. Methicillin-resistant Staphylococcus aureus (MRSA) is the most commonly implicated organism of peristomal infection. The aims of this study were to determine the contribution of nasal MRSA to wound infection in PEG and the predictors of wound infection.. A prospective study was conducted on patients undergoing PEG between September 2003 and July 2005. All patients received antibiotics prior to PEG insertion. Nasal swabs were taken from a consecutive series of patients prior to PEG insertion. Wound status of the peristomal site were prospectively evaluated at day 1, 3, and 7 following the insertion of PEG.. Thirty-one patients underwent PEG insertion (mean age, 66+/-16 years). Ten patients (32.3%) had MRSA-positive nasal swabs. Peristomal infection did not have any relationship with nasal MRSA colonization (p>0.05). Peristomal infection occurred in 4 (12.9%) cases. The rate of peristomal infections was significantly higher in patients with diabetes mellitus (p<0.05).. Nasal MRSA colonization is not associated with the risk of peristomal infections in patients receiving antibiotics prior to PEG insertion. Diabetes mellitus might be the risk factor for peristomal infection after PEG insertion.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Diabetes Complications; Female; Gastroscopy; Gastrostomy; Humans; Male; Methicillin; Methicillin Resistance; Middle Aged; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

The GeneOhm MRSA assay detects nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA). We compared the use of seeded swabs with liquid Stuart's medium and that of seeded swabs with Amies gel for the assay. Overall, the swabs with liquid Stuart's medium detected significantly greater numbers of MRSA than the swabs with Amies gel (P = 0.0003).

Topics: Carrier State; Culture Media; Humans; Methicillin Resistance; Nose; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus produces compounds that interfere with complement deposition. We hypothesized that humans have developed countermeasures to staphylococcal complement evasion and we screened for single nucleotide polymorphisms in the serine protease C1 inhibitor (C1INH) gene at amino acid position 480 (valine vs. methionine) and nasal carriage of S. aureus. In our study cohort, 38 individuals were persistently colonized by S. aureus, whereas 50 were invariably culture-negative. A trend was observed towards an increased prevalence of the Val/Val genotype in noncarriers compared to persistent carriers (OR 0.50, P=0.07). The Val/Val genotype was significantly overrepresented in noncarriers compared to 463 Caucasian blood donors (OR 0.52, P=0.02). These findings suggest that susceptibility to S. aureus nasal carriage is associated with the C1INH V480M polymorphism.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amino Acid Sequence; Amino Acid Substitution; Carrier State; Complement C1 Inactivator Proteins; Complement C1 Inhibitor Protein; Female; Genetic Predisposition to Disease; Humans; Male; Methionine; Middle Aged; Molecular Sequence Data; Nose; Polymorphism, Genetic; Serpins; Staphylococcal Infections; Staphylococcus aureus; Valine

An updated IDI-MRSA assay version was released to address the assay's low positive predictive value (PPV). A prospective analysis of two assay versions indicated no significant improvement in the PPV. Colonization by methicillin-resistant Staphylococcus aureus in 24% of patients would not have been detected if only nasal samples had been tested, as approved, by this molecular method.

Topics: Bacterial Typing Techniques; Carrier State; Charcoal; Humans; Methicillin Resistance; Nose; Population Surveillance; Reagent Kits, Diagnostic; Rectum; Sensitivity and Specificity; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is both a successful human commensal and a major pathogen. The elucidation of the molecular determinants of virulence, in particular assessment of the contributions of the genetic background versus those of mobile genetic elements (MGEs), has proved difficult in this variable species. To address this, we simultaneously determined the genetic backgrounds (spa typing) and the distributions of all 19 known superantigens and the exfoliative toxins A and D (multiplex PCR) as markers for MGEs. Methicillin- sensitive S. aureus strains from Pomerania, 107 nasal and 88 blood culture isolates, were investigated. All superantigen-encoding MGEs were linked more or less tightly to the genetic background. Thus, each S. aureus clonal complex was characterized by a typical repertoire of superantigen and exfoliative toxin genes. However, within each S. aureus clonal complex and even within the same spa type, virulence gene profiles varied remarkably. Therefore, virulence genes of nasal and blood culture isolates were separately compared in each clonal complex. The results indicated a role in infection for the MGE harboring the exfoliative toxin D gene. In contrast, there was no association of superantigen genes with bloodstream invasion. In summary, we show here that the simultaneous assessment of virulence gene profiles and the genetic background increases the discriminatory power of genetic investigations into the mechanisms of S. aureus pathogenesis.

Topics: Adult; Aged; Bacteremia; Bacterial Proteins; Blood; Carrier State; DNA, Bacterial; Female; Germany; Humans; Male; Middle Aged; Molecular Sequence Data; Nose; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Superantigens; Virulence Factors

The aim of the study was to investigate the rate of Staphylococcus aureus nasal and skin carriage in patients undergoing haemodialysis. The cultured staphylococcal isolates were subsequently characterized by molecular methods. The study group comprised 43 haemodialysed patients from whom nasal and skin swabs from the vascular access sites were collected. The identification of staphylococcal isolates and antibiotic susceptibility testing were performed on the basis of conventional diagnostic procedures. The staphylococci were further characterized using Pulsed-Field Gel Electrophoresis (PFGE). S. aureus was cultured from 12 (27.9%) patients. Only one (8.3%) patient was colonized with the microorganism both in the anterior nares and the vascular access site representing a single strain, as evidenced by PFGE analysis. Antibiotic susceptibility testing identified one (7.6%) methicillin-resistant S. aureus (MRSA) strain. PFGE typing identified several S. aureus genotypes with the lack of one specific strain responsible for colonization. However, it should be noted that among two (A and D) PFGE patterns genetically indistinguishable and closely related isolates (two isolates for each pattern) were identified. The obtained results revealed a relatively low rate of S. aureus carriage accompanied by low methicillin resistance rate and a significant genetic diversity of cultured isolates with the lack of one predominant strain responsible for colonization.

Topics: Adult; Aged; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genetic Variation; Genotype; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Nose Diseases; Prevalence; Renal Dialysis; Renal Insufficiency; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus

To evaluate the prevalence of colonization among patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection and their household contacts.. Prospective, observational laboratory study of nasal colonization among patients and their household members from September 15, 2004, to February 20, 2006.. A 600-bed, urban, academic medical center.. Fifty-one patients who presented with CA-MRSA infections and 49 household members had cultures of nasal swab specimens performed.. Skin and soft-tissue infections were seen in 50 patients (98%) and 2 household members. Twenty-one (41%) of 51 patients and 10 (20%) of 49 household members were colonized with MRSA. An additional 5 patients (10%) and 12 household members (24%) were colonized with methicillin-susceptible Staphylococcus aureus. Most MRSA isolates (95%; infective and colonizing) carried the staphylococcal cassette chromosome mec type IV complex, and 67% represented a single clone, identical to USA 300. Of the colonized household members, 5 had isolates related to the patients' infective isolate.. The frequency of CA-MRSA colonization among household members of patients with CA-MRSA infections is higher than rates reported among the general population. Among colonized household members, only half of the MRSA strains were related to the patients' infective isolate. Within the same household, multiple strains of CA-MRSA may be present.

Topics: Adult; Community-Acquired Infections; Family Characteristics; Female; Humans; Male; Methicillin Resistance; Michigan; Middle Aged; Nose; Prevalence; Prospective Studies; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus

We evaluated the use of the BD GeneOhm MRSA real-time PCR assay (BD Diagnostics, San Diego, CA) for the detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA). The initial evaluation consisted of 403 paired nasal swabs and was done using the specimen preparation provided with the kit and an in-house lysis method that was specifically developed to accommodate large-volume testing using a minimal amount of personnel time. One swab was placed in an achromopeptidase (ACP) lysis solution, and the other was first used for culture and then prepared according to the kit protocol. PCR was performed on both lysates, and results were compared to those for culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay were 98%, 96%, 77%, and 99.7% with the kit lysate and 98%, 95%, 75%, and 99.7% with the ACP lysate (P, not significant), respectively. The second evaluation was done after implementation of all-admission surveillance using PCR with ACP lysis and a sampling of 1,107 PCR-negative samples and 215 PCR-positive samples that were confirmed by culture. The results of this sampling showed an NPV of 99.9% and a PPV of 73.5% (prevalence, 6%), consistent with our initial findings. The BD GeneOhm MRSA assay is an accurate and rapid way to detect MRSA nasal colonization. When one is dealing with large specimen numbers, the ACP lysis method offers easier processing without negatively affecting the sensitivity or specificity of the PCR assay.

Topics: Bacteriological Techniques; Carrier State; Humans; Methicillin Resistance; Nose; Polymerase Chain Reaction; Predictive Value of Tests; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Identifying methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection present at admission has become important in reducing subsequent nosocomial transmission, but the most efficient surveillance methods remain to be defined. We performed anterior nares surveillance cultures of all patients upon admission to and discharge from the general internal medicine floor in our community hospital over a 7-week period, and patients completed a questionnaire on MRSA risk factors. Of the 401 patients, 41 (10.2%) had MRSA upon admission. Of the 48 risk measures analyzed, 10 were significantly associated with admission MRSA, and 7 of these were independently associated in stepwise logistic regression analysis. Factor analysis identified eight latent variables that contained most of the predictive information in the 48 risk measures. Repeat logistic regression analysis including the latent variables revealed three independent risk measures for admission MRSA: a nursing home stay (relative risk [RR], 6.18; 95% confidence interval [95% CI], 3.56 to 10.72; P < 0.0001), prior MRSA infection (RR, 3.97; 95% CI, 1.94 to 8.12; P = 0.0002), and the third latent variable (factor 3; RR, 3.14; 95% CI, 1.56 to 6.31; P = 0.0013), representing the combined effects of homelessness, jail stay, promiscuity, intravenous drug use, and other drug use. Multivariable models had greater sensitivity at detecting admission MRSA than any single risk measure and allowed detection of 78% to 90% of admission MRSA from admission surveillance cultures on 46% to 58% of admissions. If confirmed in additional studies, multivariable questionnaire screening at admission might identify a subset of admissions for surveillance cultures that would more efficiently identify most admission MRSA.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Diagnostic Tests, Routine; Efficiency; Female; Humans; Logistic Models; Male; Methicillin Resistance; Middle Aged; Multivariate Analysis; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires; Texas

The anterior nares are the most important screening site of colonization with Staphylococcus aureus. We screened 2966 individuals for S. aureus carriage with swabs of both nares and throat. A total of 37.1% of persons were nasal carriers, and 12.8% were solely throat carriers. Screening of throat swabs significantly increases the sensitivity of detection among carriers by 25.7%.

Topics: Carrier State; Female; Humans; Male; Mass Screening; Nose; Pharynx; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is one of the first pathogens which often persistently infect the airways of cystic fibrosis (CF) patients. Nasal S. aureus carriage is a risk factor for S. aureus infections in non-CF patients. Topical treatment strategies successfully eradicate nasal S. aureus carriage, thereby decreasing S. aureus infection. A prospective longitudinal multicenter study was conducted to assess whether nasal carriage represents a risk factor for S. aureus colonization of the oropharynx in young CF patients. Cross-sectional analysis revealed a significantly higher prevalence of S. aureus-positive nasal (28/80 [35%] versus 20/109 [18%]; P < 0.01) and oropharyngeal (35/80 [44%] versus 20/109 [18%]; P < 0.001) cultures in children with CF compared to a control group. The first site of S. aureus detection was the nose in 6 patients and the oropharynx in 14 patients, respectively. Longitudinal analysis demonstrated a significantly higher S. aureus prevalence (61/62 [98%] versus 47/62 [76%]; P < 0.001) and persistence (46/62 [74%] versus 31/62 [50%]; P < 0.01) in the oropharynx than in the nose. In CF patients, the oropharynx, and not the nose, was the predominant site of S. aureus infection and persistence. Hence, it is unlikely that CF patients will benefit from topical treatment strategies to eradicate nasal carriage.

Topics: Antigens, Bacterial; Carrier State; Child; Child, Preschool; Cystic Fibrosis; Female; Humans; Infant; Longitudinal Studies; Male; Nose; Oropharynx; Prevalence; Prospective Studies; Receptors, Cell Surface; Respiratory Tract Infections; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The impact of bacterial clonality on infections caused by Staphylococcus aureus is unclear.. Three hundred seventy-nine S. aureus isolates (125 methicillin-resistant S. aureus [MRSA] and 254 methicillin-susceptible S. aureus [MSSA]) were genotyped by spa typing and multilocus sequence typing. For MRSA isolates, the staphylococcal chromosomal cassette mec (SCCmec) element was also typed. Three clinical categories were identified: nasal carriage only (n=118), uncomplicated infection (n=104), and bacteremia with hematogenous complications (n=157).. By use of eBURST, 18 clonal complexes (CCs) were found in 371 isolates. Eight CCs accounted for 89% of isolates and occurred in all clinical categories. CC5 (P=.0025) and CC30 (P=.0308) exhibited a significant trend toward more frequent hematogenous complications. Isolates within spa types 2 and 16 showed the same significant trend and grouped within CC5 and CC30, respectively. SCCmec II isolates also showed the same significant trend compared with SCCmec IV; 96% were CC5 or CC30.. Although most S. aureus genotypes exhibited the capacity to cause invasive disease, strains within CC5 and CC30 exhibited a significant trend toward increasing levels of hematogenous complications. Isolates within these CCs were also implicated by use of spa and SCCmec typing. The genetic determinants underlying these findings remain to be demonstrated.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Bacteremia; Carrier State; Child; Genotype; Humans; Methicillin Resistance; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) can be a precursor to serious infection, and decolonization with topical mupirocin has been studied as a means of preventing clinical infection. Mupirocin resistance in patients with MRSA has been reported, usually in the context of widespread mupirocin use.. Patients admitted to a surgical intensive care unit (SICU) had nasal swab cultures for MRSA performed at admission, weekly, and at discharge in an active surveillance program. Collected MRSA isolates were tested for mupirocin resistance, and molecular analysis was performed. Clinical data on the characteristics and outcomes of the patients who stayed in the SICU for >48 h were collected prospectively.. Of the 302 MRSA isolates available for testing, 13.2% were resistant to mupirocin, with 8.6% having high-level resistance (minimum inhibitory concentration, >or=512 microg/mL) and 4.6% having low-level resistance (minimum inhibitory concentration, 8-256 microg/mL). Patients admitted to the SICU for >48 h who were colonized with mupirocin-resistant MRSA were more likely to have been admitted to our hospital during the previous year (P=.016), were older (P=.009), and had higher in-hospital mortality (16% vs. 33%; P=.027), compared with patients colonized with mupirocin-susceptible MRSA. Molecular analysis of the mupirocin-resistant isolates revealed that 72.5% of isolates contained staphylococcal cassette chromosome mec II. Repetitive sequence polymerase chain reaction typing revealed that high-level mupirocin resistance was present in multiple clonal groups. The rate of mupirocin use hospital-wide during the study period was 6.08 treatment-days per 1000 patient-days.. We documented a high rate of mupirocin resistance in MRSA isolates from SICU patients, despite low levels of in-hospital mupirocin use.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Drug Resistance, Multiple, Bacterial; Female; Hospitals, Private; Humans; Intensive Care Units; Male; Methicillin Resistance; Middle Aged; Missouri; Mupirocin; Nose; Phylogeny; Risk Factors; Sentinel Surveillance; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus is increasingly responsible for staphylococcal outbreaks in prison. There is limited information on the source of the outbreak strains, risk factors for infection, and transmission of these strains within a prison. We conducted a survey to determine the prevalence of nasal colonization with S. aureus in 2 New York State prisons. S. aureus isolates from clinical cultures collected from all New York State prisons during a 6-month period were compared with the colonizing strains. Analyses were conducted to determine whether prison-level characteristics were associated with colonization or infection with S. aureus. The colonization rate was 25.5% (124/487); 10.5% of the isolates were methicillin resistant, all were staphylococcal chromosomal cassette (SCC)mec type IV, and 61.5% were Panton Valentine leukocidin (PVL) positive. Surprisingly, 21.6% of the methicillin-susceptible isolates were also PVL positive. Of the clinical isolates, 48.3% were methicillin resistant, with 93.1% of the latter being SCCmec type IV and 48.3% being PVL positive. The predominant clone was USA 300. Prison-level risk factors for infection included the proportion of inmates with drug offenses, the length of inmate stay, and the jail from which inmates originated. This study suggests that both new and long-term inmates act as sources of S. aureus strains, with the more virulent of the latter preferentially being selected as pathogens.

Topics: Adolescent; Adult; Aged; Bacterial Toxins; Carrier State; Cluster Analysis; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Female; Genotype; Humans; Leukocidins; Male; Methicillin Resistance; Middle Aged; Molecular Epidemiology; New York; Nose; Polymorphism, Restriction Fragment Length; Prevalence; Prisoners; Prisons; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Determining the acquisition routes of infection is crucial to designing specific preventive approaches against Staphylococcus aureus poststernotomy mediastinitis.. From 2002 to 2004, a nasal sample was obtained from patients before cardiac surgery. We collected clinical and microbiologic data of all episodes of S aureus poststernotomy mediastinitis. A case-control study (3:1) was performed to confirm the role of previous preoperative nasal colonization by S aureus as a risk factor for S aureus poststernotomy mediastinitis. Pulsed field gel electrophoresis molecular analysis of nasal and surgical site S aureus isolates was performed to analyze their relatedness in each patient with poststernotomy mediastinitis and with other patients of the study cohort.. S aureus nasal cultures were positive in 228 (15.9%) of 1432 patients: methicillin-susceptible S aureus in 222 (15.5%) and meticillin-resistant S aureus in 6 (0.4%). S aureus poststernotomy mediastinitis was diagnosed in 17 (1.2%) of 1432 patients: 9 (3.95%) of 228 in colonized patients versus 8 (0.66%) of 1204 in noncolonized patients (P < .0001). Seven of 9 patients (1.2%) with methicillin-susceptible S aureus had an identical isolate by pulsed field gel electrophoresis in preoperative nasal and surgical-site cultures, but no clonal relatedness was shown among the isolates from these 9 patients. None of the 8 patients with methicillin-resistant S aureus poststernotomy mediastinitis had an identical isolate by pulsed field gel electrophoresis in preoperative nasal and surgical-site cultures, and the same clone of methicillin-resistant S aureus was responsible for all these cases.. Endogenous [corrected] nasal colonization often precedes methicillin-resistant S aureus poststernotomy mediastinitis, which suggests that preoperative [corrected] decontamination is adequate for preventing methicillin-susceptible [corrected] S aureus poststernotomy mediastinitis, whereas hospital infection control measures seem to be the major factor for preventing methicillin-resistant S aureus poststernotomy mediastinitis.

Topics: Aged; Female; Humans; Male; Mediastinitis; Nose; Postoperative Complications; Preoperative Care; Staphylococcal Infections; Staphylococcus aureus; Sternum

Topics: Carrier State; Humans; Intensive Care Units; Methicillin Resistance; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

The absence of a reliable method to distinguish among coagulase negative staphylococcal strains in mixed culture hinders elucidation of colonization traits and precise tracking of colonization. This study examined whether colonial morphology could be used to correctly identify coagulase negative staphylococcal strains in mixed cultures. Staphylococci were isolated from nasal and hand cultures of ten subjects at 0 and 3 months. Samples were initially screened for the predominant coagulase negative staphylococcal strain by colonial morphology. The strains were subsequently identified by phenotypic and biochemical testing. Pulsed field gel electrophoresis demonstrated that the morphologic criteria correctly grouped the strains in 91.1% (41/45) of samples. This study suggests that colonial morphology is a reliable method for the initial characterization of coagulase negative staphylococcal strains. This approach has potential value for epidemiological studies that involve establishing links between commensal flora and their potential role as pathogens in subsequent clinical infections.

Topics: Carrier State; Culture Techniques; Electrophoresis, Gel, Pulsed-Field; Hand; Humans; Nose; Staphylococcal Infections; Staphylococcus

Staphylococcus aureus (n=84) isolated from the nostrils of a healthy population from Kathmandu and from the infectious cases (n=100) from Tribhuvan University Teaching Hospital, Kathmandu, Nepal were tested from May 1996 to March 1997 in Central Department of Microbiology, Tribhuvan University, Kathmandu, Nepal by microbiological and chemical methods to find out their beta lactamase activity. Among the healthy population, in domiciliary conditions 21.4% of the isolates were found beta lactamase producers. The occurrence of beta lactamase producing S. aureus was greater among female (27.0%) than among male (17.0%), however it was not significant (X2 = 1.2309, P > 0.05). The occurrence of the same was observed high among 40 and above age groups (66.7%) and 0-9 age group (60.0%), however no association with any particular age group was observed (X2 = 16.8674, P > 0.05). The b lactamase activity of S. aureus hospital inpatients isolates was 75.0% showing high occurrence of b lactamase activity in hospital isolates compared to S. aureus isolates from healthy carriers (X2 = 52.4113, P < 0.001). No association of beta lactamase positive hospital isolates with gender (X2 = 0.2158, P > 0.05) and age group (X2 = 1.5522, P > 0.05) was observed. This study shows that the prevalence of beta lactamase positive S. aureus was greater in hospital cases than in nasal carriers in domiciliary condition indicating the requisition of further study in this field.

Topics: Adolescent; Adult; beta-Lactamases; Child; Child, Preschool; Cross Infection; Female; Humans; Infant; Infant, Newborn; Male; Middle Aged; Nepal; Nose; Penicillinase; Pilot Projects; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

We report the largest documented healthcare-associated outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (PVL(+) MRSA) in Europe. Six index patients from three long-term care facilities (LTCFs) were screened positive for PVL(+) MRSA in 2004 on admission to a community hospital in Germany. The purpose of this prospective study was to describe the prevalence of PVL(+) MRSA in the LTCFs before and after infection control interventions. Screening for MRSA with or without PVL was performed in all three LTCFs in 2004 [453 residents, 240 healthcare workers (HCWs)] and 2005 (440 residents, 192 HCWs). Swabs from anterior nares and wounds, if applicable, were collected. Colonised residents and staff were treated with mupirocin nasal ointment and topical antiseptics, and staff were provided with hygiene education. Total MRSA carrier rate of residents and HCWs in 2004 was 11.3% (PVL(+) MRSA 9.1%, PVL(-) MRSA 2.2%). There were comparable carrier rates between residents and HCWs in each LTCF. All PVL(+) MRSA isolates were of clonal origin (MLST 22) representing a novel spa sequence type t310. A decrease in total MRSA prevalence (from 11.3 to 5.5%) and PVL(+) MRSA (from 9.1 to 3.3%) was observed in 2005. The rate of PVL(-) MRSA remained unaffected. No symptomatic skin infections were noted among residents or HCWs. In this outbreak incomplete control of PVL(+) MRSA presumably resulted from difficult and delayed detection and decolonisation of carriers, incomplete compliance with control measures and lack of enforcement by public health authorities.

Topics: Administration, Intranasal; Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Toxins; Carrier State; Cross Infection; Disease Outbreaks; Exotoxins; Female; Germany; Guideline Adherence; Health Personnel; Humans; Infection Control; Leukocidins; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Patients; Staphylococcal Infections; Staphylococcus aureus; Wounds and Injuries

This point-prevalence study was conducted to establish rates of meticillin-resistant Staphylococcus aureus (MRSA) nasal carriage in GPs in three counties in the West of Ireland. One hundred and twenty GPs were randomly selected for the study and 78 participated. The prevalence rate of nasal carriage of MRSA in these participants was 7.7%. A number of GPs in the West of Ireland have nasal carriage of MRSA. The results emphasise the need for high standards of infection control in primary care.

Topics: Adult; Carrier State; Female; Humans; Infection Control; Ireland; Male; Methicillin Resistance; Middle Aged; Nose; Physicians, Family; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

From July 2005 to October 2006, a total of 3,046 children, of ages between 2 months and 5 years, presented for a well-child health care visit to one of three medical centers, which are located in the northern, central, and southern parts of Taiwan, and were surveyed for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA). The overall prevalences of S. aureus and MRSA nasal carriage among the children were 23% and 7.3%, respectively (18% and 4.8% in the central region, 25% and 6.7% in the southern region, and 27% and 9.5% in the northern region). Of the 212 MRSA isolates (96%) available for analysis, a total of 10 pulsed-field gel electrophoresis (PFGE) patterns with two major patterns (C [61%] and D [28%]) were identified. One hundred forty-nine isolates (70%) contained type IV staphylococcal cassette chromosome mec (SCCmec) DNA, and 55 isolates (26%) contained SCCmec V(T). The presence of Panton-Valentine Leukocidin (PVL) genes was detected in 60 isolates (28%). Most MRSA isolates belonged to one of two major clones, characterized as sequence type 59 (ST59)/PFGE C/SCCmec IV/absence of PVL genes (59%) and ST59/PFGE D/SCCmec V(T)/presence of PVL genes (25%). We concluded that between 2005 and 2006, 7.3% of healthy Taiwanese children were colonized by MRSA in nares. MRSA harbored in healthy children indicates an accelerated spread in the community.

Topics: Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Child, Preschool; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Genotype; Humans; Infant; Leukocidins; Methicillin Resistance; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Taiwan

To compare the distribution of genes encoding classical and newly described enterotoxins among Staphylococcus aureus, associated with carriage and infection.. Forty-five nasal isolates from carriers and 42 clinical isolates were included. The genes sea to see and seg to sei as well as sem, sen, seo and seu were tested using multiplex and conventional PCR. The most frequently found toxin genes were egc-related genes, in particular the combination seg and sei (n = 55, 63.1%), followed by sen and seu (n = 54, 62.1%), sem (n = 51, 58.6%) and seo (n = 48, 55.2%). Significant differences were found for seg and sei combination (33 of the nasal vs 22 of the infection isolates, P = 0.048) as well as for the genes sem (P = 0.004), sen (P = 0.029) and seo (P = 0.032). Regarding the classical toxin genes no significant differences between the two groups of isolates were found.. Significant differences between infection and carriage strains were found only for the egc-related genes, which were more common in the nasal isolates.. The egc-related enterotoxin genes seem to be more prevalent in carriage- than in infection-associated S. aureus isolates. The possible contribution of egc-related genes in determining the potential for nasal carriage requires further investigation.

Topics: Carrier State; DNA, Bacterial; Enterotoxins; Genes, Bacterial; Humans; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus

In hostile environments diversity within a bacterial population may be beneficial for the fitness of the microbial community as a whole. Here we analysed the population diversity of Staphylococcus aureus in infecting and colonizing situations. In the study, performed independently in two German centres, the heterogeneity of the S. aureus population was determined by quantifying the occurrence of phenotypic variants (differences in haemolysis, pigmentation, colony morphology) in primary cultures from nose, oropharyngeal and sputum specimens from cystic fibrosis (CF) patients and in nose swabs from healthy S. aureus carriers. The proportion of heterogeneous samples, the number of clearly distinguishable isolates per sample and the qualitative differences between phenotypes was significantly higher in CF sputum specimens than in the other samples. The heterogeneity of the S. aureus population could be correlated with high bacterial densities in the sputum samples. In patients co-infected with Pseudomonas aeruginosa lower S. aureus bacterial loads and less heterogeneity in the S. aureus population were observed. Typing of all S. aureus isolates from heterogeneous samples by pulsed-field gel electrophoresis or spa typing revealed that the bacteria were polyclonal in 30%, monoclonal with minor genetic alterations in 25% or not distinguishable in 69% of the specimens. Some specimens harboured monoclonal and polyclonal variants simultaneously. Importantly, differences in antibiotic susceptibility were detected in phenotypic S. aureus variants within a single specimen. Diversification of a S. aureus population is highly favoured during chronic CF lung infection, supporting the general hypothesis that maintenance of intrahost diversity can be of adaptive value, increasing the fitness of the bacterial community.

Topics: Adolescent; Adult; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cystic Fibrosis; Electrophoresis, Gel, Pulsed-Field; Female; Hemolysis; Humans; Infant; Male; Microbial Sensitivity Tests; Nose; Oropharynx; Phenotype; Sputum; Staphylococcal Infections; Staphylococcus aureus

The objective was to describe the prevalence of MRSA in Oslo, Norway, before and after introduction of a new National MRSA Control Guideline.. From 1993 to 2006, we prospectively collected clinical and microbiological data on all MRSA cases in Oslo, Norway. Two MRSA guidelines; a strict Ullevål Standard MRSA Guideline and a less strict National MRSA Control Guideline were compared.. During 1993-2006, 358 MRSA cases were registered in Oslo; 43.9% detected in Ullevål University Hospital, 21.2% in nursing homes, and 18.7% in primary healthcare. One out of three (30.4%) were import-associated, and one out of ten (11.2%) were healthcare personnel. From 2004 on, a new National MRSA Control Guideline was introduced in primary healthcare, served by the community infection control. From 2004 on, there was a 4-6-fold increase of MRSA in primary healthcare (p = 0.038) and nursing homes (p = 0.005). Increase of MRSA cases at Ullevål (p < 0.001) was import-associated or from outbreaks in primary healthcare. There was no increase of internal spread in the hospital.. These data indicate that perhaps a less strict national MRSA infection control guideline in Norway may be associated with the 4-6-fold increase of MRSA cases in the community after 2003.

Topics: Disease Outbreaks; Guidelines as Topic; Hand; Humans; Infection Control; Mass Screening; Methicillin Resistance; Norway; Nose; Staphylococcal Infections; Staphylococcus aureus

Continuous subcutaneous insulin infusion (CSII) is a commonly used, safe intensive insulin therapy method effective in maintaining normoglycaemia. The disadvantage of CSII are skin infections of the catheter injection site. The aim of the study was to gain insight on the colonization of subcutaneous insulin pump catheters by skin flora and to investigate the correlation between Staphylococcus aureus carrier state (presence in the nose), its presence on the skin and catheter. 141 catheters obtained from 94 children with T1DM and CSII were examined using the semi quantitative culture technique of Maki. The result was positive in 34 examinations (24.1%) in 30 children (31.9%). Most often coagulase negative staphylococci were isolated (30), mainly Staphylococcus epidermidis, 1/3 of the staphylococci were methicillin resistant. S. aureus was detected in 7 examinations in 6 children. S. aureus carrier state was proved in 31.9% of all examined patients, more often in children with a positive catheter culture (41.4%), there were no MRSA. No correlation between S. aureus carrier state and catheter colonization was shown. Statistically significant correlations between: coagulase negative staphylococci presence, including the methicillin resistant strains, on the skin and on the catheter surface (p< 0.0001); glycosylated hemoglobin (HbA1c) and bacteria catheter colonization (p = 0.0335) were observed. Subcutaneous catheter colonization by microorganisms often occurs in CSII. Microorganisms found on the skin are the most frequent cause of the subcutaneous catheter infection.

Topics: Adolescent; Adult; Carrier State; Catheterization; Child; Child, Preschool; Coagulase; Female; Glycated Hemoglobin; Humans; Infant; Insulin Infusion Systems; Male; Methicillin Resistance; Nose; Skin; Staphylococcal Infections; Staphylococcus

To determine colonization rates of Staphylococcus aureus given the potential for future intervention trials aimed at reducing surgical-site infectious morbidity, and to estimate methicillin-resistant Staphylococcus aureus (MRSA) rates in our patient population.. Prospective pilot investigation comprising data from 104 gravidas admitted to an urban labor and delivery unit. All underwent anterior nares culture collection with a subset also undergoing vaginal culture collection.. Twenty-two percent of women were colonized in the anterior nares. Of the 28 women who had vaginal cultures collected, 4/28 (14.2%) demonstrated Staphylococcus aureus colonization. There was 82% concordance between the nares and vagina. Nine percent of isolates were MRSA strains. Overall, 2/96 (2.1%) of women were MRSA-colonized.. Rates of Staphylococcus aureus colonization among gravidas entering labor and delivery are modest and consistent with the general population. MRSA rates among gravidas appear to be reassuringly low in this pilot study.

Topics: Adolescent; Adult; Cohort Studies; Community-Acquired Infections; Female; Humans; Methicillin Resistance; Nose; Ohio; Pilot Projects; Pregnancy; Pregnancy Complications, Infectious; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Urban Population; Vagina

Two hundred healthy horses housed at 23 different farms and one clinic and 42 persons in close contact with these horses were screened for the presence of methicillin resistant staphylococci. Samples were taken from the nose and the pastern of the horses and from the nose and throat of the humans and incubated in selective media. Isolates were identified by standard techniques and their susceptibilities were tested using an agar diffusion method. Methicillin-resistant strains were tested for the presence of the mecA gene by PCR. In 45 horses (22.5%) and 15 humans (35.7%) mecA positive staphylococci were found. All isolates were coagulase negative staphylococci, except for one methicillin-resistant Staphylococcus aureus isolated from a veterinarian. Staphylococcus sciuri was the predominant species found among the methicillin resistant staphylococci (MRS) in the horses, whereas S. epidermidis predominated in the humans. From the horses, often more than one species of MRS could be isolated, resulting in a total of 175 mecA positive equine isolates. The equine isolates were predominantly susceptible to most antimicrobials tested, whereas the human isolates showed more resistance. In conclusion, no methicillin-resistant Staphylococcus aureus was found in healthy horses in the Netherlands, but methicillin-resistant coagulase negative staphylococci were found frequently. Further studies are needed in order to investigate whether horses can be a reservoir for MRS or the mecA gene for humans.

Topics: Animals; Bacterial Proteins; Carrier State; DNA Primers; Female; Horse Diseases; Horses; Humans; Male; Methicillin Resistance; Microbial Sensitivity Tests; Netherlands; Nose; Penicillin-Binding Proteins; Pharynx; Polymerase Chain Reaction; Prevalence; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus

Topics: Carrier State; Community-Acquired Infections; Female; Humans; Male; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is a common cause of disease, particularly in colonized persons. Although methicillin-resistant S. aureus (MRSA) infection has become increasingly reported, population-based S. aureus and MRSA colonization estimates are lacking.. Nasal samples for S. aureus culture and sociodemographic data were obtained from 9622 persons > or = 1 year old as part of the National Health and Nutrition Examination Survey, 2001-2002. After screening for oxacillin susceptibility, MRSA and selected methicillin-susceptible S. aureus isolates were tested for antimicrobial susceptibility, pulsed-field gel electrophoresis clonal type, toxin genes (e.g., for Panton-Valentine leukocidin [PVL]), and staphylococcal cassette chromosome mec (SCCmec) type I-IV genes.. For 2001-2002, national S. aureus and MRSA colonization prevalence estimates were 32.4% (95% confidence interval [CI], 30.7%-34.1%) and 0.8% (95% CI, 0.4%-1.4%), respectively, and population estimates were 89.4 million persons (95% CI, 84.8-94.1 million persons) and 2.3 million persons (95% CI, 1.2-3.8 million persons), respectively. S. aureus colonization prevalence was highest in participants 6-11 years old. MRSA colonization was associated with age > or = 60 years and being female but not with recent health-care exposure. In unweighted analyses, the SCCmec type IV gene was more frequent in isolates from participants of younger age and of non-Hispanic black race/ethnicity; the PVL gene was present in 9 (2.4%) of 372 of isolates tested.. Many persons in the United States are colonized with S. aureus; prevalence rates differ demographically. MRSA colonization prevalence, although low nationally in 2001-2002, may vary with demographic and organism characteristics.

Topics: Adolescent; Adult; Age Factors; Aged; Bacterial Toxins; Carrier State; Child; Child, Preschool; Community-Acquired Infections; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Ethnicity; Female; Humans; Infant; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Molecular Epidemiology; Nose; Prevalence; Sex Factors; Socioeconomic Factors; Staphylococcal Infections; Staphylococcus aureus; United States

By analyzing the colonization of the anterior nares in cardiothoracic surgery patients on admission, nasal cocolonization by methicillin-susceptible Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci was detected in 8/235 (3.4%) specimens. Consequently, in a low-methicillin-resistant S. aureus (MRSA) setting, a molecular MRSA screening test targeting the mecA gene and an S. aureus-specific gene in parallel and applied directly to clinical specimens would be associated with an unacceptable positive predictive value of about 40%.

Topics: Bacterial Proteins; Coagulase; False Positive Reactions; Humans; Methicillin; Methicillin Resistance; Nose; Penicillin-Binding Proteins; Predictive Value of Tests; Staphylococcal Infections; Staphylococcus aureus

Topics: Blood Component Removal; Blood Platelets; Carrier State; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide, and MRSA infections are frequent in intensive care units (ICUs).. A prospective study was implemented to investigate the risk factors for ICU-acquired MRSA infections.. This study was conducted in surgical and neurologic ICUs from May to November 2003. The patients staying in ICUs more than 48 hours were included in the study. All of the patients were visited daily, and data were recorded on individual forms for each patient until discharge or death. Nasal swab cultures were done within 48 hours of ICU admission and repeated every week until the patients colonized with MRSA or were discharged from ICUs. ICU-acquired MRSA infection was diagnosed when MRSA was isolated from the infected site.. Overall, 249 patients were followed during the study. MRSA infection was detected in 21 (8.4%) of these patients. The most frequent infection was primary bloodstream infection (10/21, 47%). It was followed by pneumonia (8/21, 38%) and surgical site infection (3/21, 14%). Nasal MRSA colonization was detected in 59 (23.7%) patients, and 12 of them (20.3%) developed MRSA infection. In univariate analysis, hospitalization period in an ICU, intraabdominal and orthopedic pathologies, mechanical ventilation, central venous catheter insertion, total parenteral nutrition, previous antibiotic use, surgical ICU stay, nasal MRSA colonization, and presence of more than 2 patients having nasal colonization in the same ICU at the same time were found significant for MRSA infections. In multivariate analysis; hospitalization period in an ICU (OR, 1.090; 95% CI: 1.038-1.144, P = .001), central venous catheter insertion (OR, 1.822; 95% CI: 1.095-3.033, P = .021), previous antibiotic use (OR, 2.337; 95% CI: 1.326-4.119, P = .003) and presence of more than 2 patients having nasal colonization in the same ICU at the same time (OR, 1.398; 95% CI: 1.020-1.917, P = .037) were independently associated with MRSA infections.. According to the our results, hospitalization period in an ICU, presence of patients colonized with MRSA in the same ICU at the same time, previous antibiotic use, and central venous catheter insertion are independent risk factors for ICU-acquired MRSA infections. Detection of these factors helps to decrease the rate of MRSA infections in the ICUs.

Topics: Adult; Aged; Anti-Bacterial Agents; Bacteremia; Catheterization; Cross Infection; Female; Humans; Intensive Care Units; Length of Stay; Male; Methicillin Resistance; Middle Aged; Multivariate Analysis; Nose; Parenteral Nutrition; Pneumonia; Prospective Studies; Respiration, Artificial; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious nosocomial problem, globally distributed. Decolonization with mupirocin can be used to control its dissemination.. To determine the incidence of mupirocin resistance among MRSA carriers from an intensive care unit.. We obtained 2723 nasal swabs during 3 years. Resistance to methicillin and mupirocin were verified (agar diffusion and the E test) and confirmed by polymerase chain reaction (PCR) (mecA for methicillin; ileS-2 and mupA for mupirocin). Plasmid-curing procedure and pulsed-field gel electrophoresis (PFGE) were employed in isolates exhibiting high resistance to mupirocin (HR-Mup) and in other selected organisms.. The overall incidence of HR-Mup among MRSA carriers during the studied period was 4.84% (8/165); however, the incidence decreased from 13.04% (6/46) in the first year to 3.5% (2/57) in the second year and was 0% in the last year (P = .02). LR-Mup, in contrast, increased significantly (P = .01).. Plasmid-curing procedure showed the plasmid location of genes responsible for HR-Mup. PFGE demonstrated that most MRSA, including the isolates with HR-Mup, were genetically related. The decline in HR-Mup may be attributable to the plasmid location of genes (ileS-2/mupA) and to the fact that all patients colonized with HR-Mup MRSA died or were discharged in a relatively short period of time.

Topics: Bacterial Proteins; Carrier State; Cross Infection; DNA, Bacterial; Drug Resistance, Bacterial; Genes, Bacterial; Humans; Incidence; Intensive Care Units; Methicillin Resistance; Microbial Sensitivity Tests; Molecular Epidemiology; Mupirocin; Nose; Nuclear Proteins; Penicillin-Binding Proteins; Plasmids; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus

The prevalence and associated factors of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation were investigated among patients in geriatric hospitals in Korea. S. aureus was isolated from 317 (50.2%) of 632 patients. The nasal MRSA colonisation prevalence was 36.1%. In bivariate analysis, stay in an intensive care unit, decreased functional status, recent use of antibiotics, use of urinary catheters and the existence of skin breaks were associated with nasal MRSA colonisation (p < 0.05). Of these factors, only decreased functional status and recent use of systemic antibiotics were associated independently with nasal MRSA colonisation following logistic regression analysis.

Topics: Aged; Carrier State; Female; Geriatrics; Hospitals; Humans; Korea; Male; Methicillin Resistance; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

After the introduction of routine treatment for every nasal carrier of methicillin-resistant Staphylococcus aureus, active follow-up surveillance for nosocomial methicillin-resistant S. aureus infection was conducted for 5 years in an intensive care unit of a tertiary-care teaching hospital. There was a significant decrease in the incidence of nosocomial methicillin-resistant S. aureus infection during the later years of follow-up. Decolonization of nasal carriers of methicillin-resistant S. aureus is probably associated with such findings.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Brazil; Chlorhexidine; Cross Infection; Humans; Infection Control; Intensive Care Units; Methicillin Resistance; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus

The identification of mannitol salt positive, coagulase-negative staphylococci (CNS) is often disregarded when Staphylococcus aureus is screened in clinical samples using mannitol salt agar. However, the emergence of CNS as important human pathogens has indicated that reliable methods for the identification of clinically significant CNS are of great importance in understanding the epidemiology of infections caused by them. The identification and molecular characterization of mannitol salt positive CNS from nasal samples of medical personnel and students is reported here. A total of 84 mannitol salt positive staphylococcal isolates were obtained from 240 nasal samples, of which 15 were CNS. The API STAPH system classified the CNS isolates into six species, and one-third of the isolates were identified with confidence levels of <80 %. 16S-23S rRNA intergenic spacer length polymorphism analysis (ITS-PCR) identified only two species (Staphylococcus haemolyticus and Staphylococcus saprophyticus). This identification was confirmed by antibiotyping, species-specific PCR and PFGE. The results from this study indicate that ITS-PCR is a potentially useful and reliable tool, enabling hospital laboratories to obtain rapid, full and accurate identification of CNS at the species level.

Topics: Bacterial Typing Techniques; Carrier State; Coagulase; DNA, Bacterial; DNA, Ribosomal Spacer; Electrophoresis, Gel, Pulsed-Field; Humans; Mannitol; Microbial Sensitivity Tests; Nose; Physicians; Reagent Kits, Diagnostic; RNA, Ribosomal, 16S; RNA, Ribosomal, 23S; Species Specificity; Staphylococcal Infections; Staphylococcus; Students, Medical

Topics: Aged; Bacterial Toxins; Carrier State; Community-Acquired Infections; Female; Gene Expression; Humans; Logistic Models; Male; Methicillin Resistance; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United States

The epidemiology of staphylococcal colonization and community-associated methicillin-resistant Staphylococcus aureus (MRSA) is changing, and little is known from the national perspective.. To describe the U.S. epidemiology of S. aureus nasal colonization, compare risk factors for colonization with methicillin-sensitive S. aureus (MSSA) versus MRSA, and compare antibiotic resistance patterns and genetic factors of colonizing strains of S. aureus.. Secondary analysis of data from the National Health and Nutrition Examination Survey (NHANES), a stratified, multistage probability sample.. United States.. 2001-2002 NHANES participants older than 1 year of age.. Colonization of MSSA and MRSA, risk factors for colonization, antimicrobial resistance, and percentage of isolates with selected genetic factors.. The prevalence of colonization with S. aureus and with MRSA was 31.6% and 0.84%, respectively, in the noninstitutionalized U.S. population. People younger than 65 years of age, men, persons with less education, and persons with asthma were more likely to acquire S. aureus. Persons of black race and those of Mexican birth had lower risk for S. aureus colonization. Persons 65 years of age or older, women, persons with diabetes, and those who were in long-term care in the past year were more likely to have MRSA colonization. Hispanic persons had statistically significantly less risk than white persons. Isolates of MRSA with staphylococcal chromosomal cassette mec type IV (which is often associated with community-associated MRSA) were statistically significantly more likely to be sensitive to erythromycin, clindamycin, and ciprofloxacin.. Colonizing isolates may be different from isolates associated with infection. Risk factors identified may differ from those associated with invasive disease. The 2001-2002 NHANES data are several years old and may not reflect the most recent changes in epidemiology, but they are the only national data available.. Characteristics of persons with MSSA and MRSA seem to differ. These findings may be useful for differentiating those who may be at risk for MRSA.

Topics: Aged; Bacterial Toxins; Carrier State; Community-Acquired Infections; Female; Gene Expression; Humans; Logistic Models; Male; Methicillin Resistance; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United States

Topics: Adult; Colony Count, Microbial; Female; Hospitals; Humans; Italy; Male; Medical Staff, Hospital; Methicillin Resistance; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) by PCR can be performed directly from nasal specimens with the IDI-MRSA assay. To improve the efficiency of screening, we evaluated the performance of the IDI-MRSA assay for the detection of MRSA from pooled and unpooled specimens cultured in a selective broth. Of the 287 specimens evaluated, 71 were culture and PCR positive, 203 were culture and PCR negative, 3 were culture positive and PCR negative, 8 were culture negative and PCR positive, and 2 remained inhibited. A methicillin-susceptible Staphylococcus aureus isolate was recovered from five of the eight specimens with false-positive PCR results. Compared to the results of culture, the sensitivity, specificity, and positive and negative [corrected] predictive values of the IDI-MRSA assay for detection of MRSA from broth were 96%, 96%, 90%, and 98%, respectively. Following implementation of the IDI-MRSA assay, PCR-positive broths were subcultured for evaluation of assay performance. Of the 298 IDI-MRSA assay-positive broths, the results for 103 could not be confirmed by culture. A methicillin-susceptible S. aureus (MSSA) isolate was recovered from 77 of these 103 broths. Repeat testing by the IDI-MRSA assay directly with the MSSA isolates confirmed the original positive PCR result. The positive predictive value of the IDI-MRSA assay fell from 90% during the evaluation phase to 65% postimplementation. The IDI-MRSA assay performed well for the detection of MRSA from a selective broth compared to the performance of the detection of MRSA from culture. However, because of the burden associated with implementation of infection control precautions, cultures remain essential in confirming positive IDI-MRSA results.

Topics: Bacterial Typing Techniques; Culture Media; Humans; Methicillin Resistance; Nose; Reagent Kits, Diagnostic; Rectum; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

The epidemiology and risks of Staphylococcus aureus carriage in continuous peritoneal dialysis (CPD) patients was studied in a single tertiary-care institution. On outpatient visits samples for culture were routinely taken prospectively from the CPD catheter exit site and the vestibulum nasi. Seventy-five patients with at least one culture positive for S. aureus in this period were included: 43 had genotypically identical S. aureus strains in over 80% of the cultures and were classified as persistent carriers; 32 were intermittent carriers. Persistent carriage was associated with a threefold higher risk for CPD-related infections and sixfold higher rates of vancomycin consumption compared to those for the intermittent carriers. No methicillin or vancomycin resistance was detected.

Topics: Adolescent; Adult; Aged; Carrier State; Female; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Bacterial Proteins; Carrier State; False Positive Reactions; Humans; Methicillin; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Penicillin-Binding Proteins; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus

In the study presented here 251 nasal swabs obtained from medical staff were directly investigated for MRSA using a commercial multiplex PCR system in parallel with conventional culture methods to determine the usefulness of PCR for rapid screening. Both methods identified 3.2% (8/251) of specimens as MRSA-positive; one sample was culture-positive only, and three were PCR-positive only. PCR correctly identified 215 of 239 (90%) negative swab samples, but one sample with weak cultural growth was not detected and was therefore considered false negative. The comparative sensitivity of culture versus PCR was 75% (9/12) versus 91.6% (11/12). Although PCR had a low positive predictive value (31.4%) its negative predictive value was high (99.5%). The results of this study indicate the multiplex PCR is suitable for the rapid identification of MRSA-negative individuals directly from nasal swabs in populations with a low MRSA prevalence, but positive results need to be confirmed by culture.

Topics: Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Methicillin Resistance; Nose; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

We conducted this study to assess the rate of methicillin-resistant Staphylococcus aureus colonization and its association with infection among infants hospitalized in methicillin-resistant S aureus-endemic NICUs.. Between March 2003 and February 2004, surveillance culture specimens from the nares, postauricular areas, axillae, and umbilicus of infants admitted to the NICUs at a children's hospital in Taiwan were obtained weekly for the detection of methicillin-resistant S aureus. All colonized and clinical isolates from each study infant with methicillin-resistant S aureus infection were genotyped with pulsed-field gel electrophoresis, with Sma1 digestion, and compared.. A total of 783 infants were included in this study. Methicillin-resistant S aureus colonization was detected for 323 infants during their NICU stays, with detection with the first 2 samples for 89%. Nares and umbilicus were the 2 most common sites of initial colonization. Methicillin-resistant S aureus colonization was associated significantly with premature birth (< or = 28 weeks) and low birth weight (< or = 1500 g), and infants with colonization had a significantly higher rate of methicillin-resistant S aureus infection, compared with those without colonization (26% vs 2%). Methicillin-resistant S aureus colonization was noted for 84 of 92 infants with methicillin-resistant S aureus infections. Of the 68 episodes with previous colonization and isolates available for genotyping analysis, colonized and clinical isolates were indistinguishable in 63 episodes, highly related in 2 episodes, and distinct in 3 episodes.. More than 40% of the hospitalized infants were colonized with methicillin-resistant S aureus during their stay in methicillin-resistant S aureus-endemic NICUs; this was associated significantly with methicillin-resistant S aureus infection. Most infants with methicillin-resistant S aureus infections had previous colonization with an indistinguishable strain.

Topics: Axilla; Bacteremia; Bacterial Typing Techniques; Birth Weight; Carrier State; Cross Infection; DNA, Bacterial; Ear, External; Female; Gestational Age; Hospitals, Pediatric; Hospitals, University; Humans; Infant; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Intensive Care Units, Neonatal; Male; Methicillin Resistance; Nose; Patient Isolation; Skin; Sputum; Staphylococcal Infections; Staphylococcus aureus; Taiwan; Umbilicus

The IDI-MRSA assay (Infectio Diagnostic, Inc., Sainte-Foy, Quebec, Canada) with the Smart Cycler II rapid DNA amplification system (Cepheid, Sunnyvale, CA) appears to be sensitive and specific for the rapid detection of nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the sensitivity and specificity of this assay under conditions in which both the nose and cutaneous groin specimens were analyzed together and compared the accuracy of this PCR approach to that when these specimens were tested separately and by culture assays in an inpatient population with known high rates (12 to 15%) of MRSA colonization. Of 211 patients screened, 192 had results assessable by all three methods (agar-broth culture, separate nose and groin IDI-MRSA assay, and combined nose-groin IDI-MRSA assay), with MRSA carriage noted in 31/192 (16.1%), 41/192 (21.4%), and 36/192 (18.8%) patients by each method, respectively. Compared to agar culture results, the sensitivity and specificity of the combined nose-groin IDI-MRSA assay were 88.0% and 91.6%, respectively, whereas when each specimen was processed separately, the sensitivities were 90.0% (nose) and 83.3% (groin) and the specificities were 91.7% (nose) and 90.2% (groin). IDI-MRSA assay of a combined nose-groin specimen appears to have an accuracy similar to that of the current recommended PCR protocol, providing results in a clinically useful time frame, and may represent a more cost-effective approach to using this assay for screening for MRSA colonization.

Topics: Groin; Humans; Methicillin Resistance; Nose; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is the most common cause of serious infections in patients undergoing long-term haemodialysis (HD). S. aureus infections in HD patients are associated with considerable morbidity and mortality. Especially, methicillin-resistant S. aureus (MRSA) strains are becoming increasingly multidrug-resistant and have recently developed resistance to vancomycin, used successfully to treat MRSA for more than 30 years. In vitro determination of resistance patterns of S. aureus is critical in terms of administering suitable antimicrobial treatment. The objective of this study was to identify the frequency of S. aureus among diabetic and non-diabetic HD patients and to investigate resistance patterns against various antibiotics used broadly for treatment. This study was carried out between January 2004 and December 2004. In the present survey, 261 patients undergoing HD treatment from three HD units in Hatay were examined. A total of 148 Staphylococcus aureus strains were processed to assess their occurrence rates and antimicrobial susceptibility profiles. S. aureus positivity was determined in 148 (56.7%) of the 261 HD patients and 26 (16.2%) of the 160 individuals in the control group. The difference was significant (p < 0.001). HD length was found to be 38.4 +/- 24.3 months in the patients of S. aureus carrier and 27.3 +/- 18.5 months in non-carrier patients. Significant correlation was also identified between durations those on HD and the isolation of S. aureus (p < 0.001). However, the carrier state was unrelated to the presence of diabetes mellitus (DM), age or sex. In conclusion, nasal carriage of S. aureus was found to be more prevalent in HD patients than that in those in the control group. Also, it is concluded that DM was not a risk factor for the nasal carriage of S. aureus. In addition, the rates of antibiotic resistance of S. aureus strains were found to be quite higher in HD patients than in the control group (p < 0.05).

Topics: Case-Control Studies; Diabetes Mellitus; Female; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

To improve efficiency in detecting nasal methicillin-resistant Staphylococcus aureus (MRSA), we evaluated a multiplex PCR using pre-enrichment of the specimen in selective broths, and compared it with detection performed by routine tests in hospital laboratories. Nasal swab specimens from 311 patients were inoculated onto mannitol-salt agar (MSA) at the hospital laboratories and in two Mueller-Hinton broths with 7% NaCl containing oxacillin at concentrations of 2 and 4 micro g/ml. Isolates on MSA were identified as MRSA by classical laboratory tests (coagulase and oxacillin disk diffusion tests). Oxacillin broth cultures were subcultured on blood agar and MRSA isolates were identified by coagulase and susceptibility tests, including agar dilution and the oxacillin-screening method (gold standard method). Simultaneously, multiplex-PCR was performed from the selective broths to detect S. aureus species-specific and mecA gene segments (OxMPCR method). Thirty-two S. aureus isolates were recovered: 29 (90.6%) were MRSA strains and 3 (9.4%) were oxacillin-susceptible isolates. Twenty-eight (96.5%) MRSA isolates were detected by OxMPCR, while 17 (58.6%) were identified by routine tests (P=0.002). This new method for detection of MRSA nasal carriers showed higher sensitivity and led to faster reporting--i.e., within 24 h--of results.

Topics: Bacterial Proteins; Carrier State; Culture Media; Humans; Methicillin Resistance; Nose; Penicillin-Binding Proteins; Polymerase Chain Reaction; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus

To determine how consistently patients are colonized with methicillin-resistant Staphylococcus aureus (MRSA) at various sites and how many subtypes can be carried simultaneously by a single patient.. A 28-bed Intensive care unit in a tertiary-care referral hospital.. A total of 1,181 patients were screened by culture of swab specimens obtained from the nose, throat, groin, and axilla on admission to the intensive care unit (ICU), twice weekly during their ICU stay, and at discharge.. MRSA was isolated at least once from 224 patients. Of these isolates, 359 were selected from 32 patients to be subtyped using pulsed-field gel electrophoresis. The rate of compliance with collection of swab specimens was 79.9%. The combination of sites colonized varied frequently over time for many patients. Of patients who had swab specimens obtained twice in 1 day, 8.7% had discordant results from the 2 swab sets. No patient had a clinical isolate that was not of an identical subtype to an isolate from an anatomical site that was sampled for screening. Half the patients carried multiple subtypes during their stay, with up to 4 subtypes per patient.. The findings of this study may indicate that these patients have been colonized with MRSA on more than one occasion, possibly because of multiple breaches in infection control procedure. In MRSA-colonized patients, anatomical sites were intermittently colonized and carriage of multiple subtypes was common. These findings indicate that MRSA carriage is not a fixed state but may vary over time.

Topics: Axilla; Carrier State; Electrophoresis, Gel, Pulsed-Field; Groin; Humans; Intensive Care Units; Methicillin Resistance; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

In order to evaluate the value of bacterial cultures taken from the throat, 266 patients with MRSA were retrospectively assessed. At the time when MRSA was first detected in the patient, the most frequent sites positive for MRSA were a skin lesion (110 patients, 41%), the anterior nares (109 patients, 41%), and the throat (102 patients, 38%). In 26%, 17%, and 17% of the patients, a skin lesion, the anterior nares, and the throat, respectively, were the only site where MRSA was seen. In 123 patients cultured for MRSA because of a close contact with an already known MRSA patient, 65 patients (53%) were positive for MRSA in their throat and in 40 patients (33%), throat was the only sample site with MRSA at the time when the patient was found to be MRSA positive. 146 of the 266 patients (55%) were colonized with MRSA in the throat any time throughout the period they were MRSA positive. We conclude that throat is an important reservoir for MRSA and that samples taken from the throat should be included in screening patients for MRSA.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Methicillin Resistance; Middle Aged; Nose; Pharyngeal Diseases; Pharynx; Staphylococcal Infections; Staphylococcus aureus

We report the effectiveness of preemptive enhanced barrier precautions in containing a methicillin-resistant Staphylococcus aureus (MRSA) outbreak in a university hospital burn unit and further controlling endemic nosocomial MRSA infection in the unit during the succeeding 27 months.. During a 6-month period, 12 patients in a 7-bed burn unit were found to be colonized (7) or infected (5) by MRSA. An epidemiologic study was undertaken.. Seven of the 10 strains of MRSA from patients that were available for DNA typing were clonally identical. Early in the outbreak, a health care worker was found to be a concordant nasal carrier and was successfully decolonized with nasal mupirocin. However, despite stringent compliance with isolation of MRSA-positive patients (targeted precautions), new cases of MRSA colonization or infection continued to occur. The outbreak was rapidly terminated after implementing preemptive barrier precautions with all patients in the unit: a new, clean gown and gloves for any physical contact with the patient or their environment. Although 25% of all nosocomial S aureus isolates in our hospital are resistant to methicillin, the incidence of endemic MRSA colonization and infection in the burn unit has remained very low since implementing barrier precautions unit wide (baseline rate, 2.2 [95% CI: 1.0-4.2] cases per 1000 patient-days; outbreak rate, 7.2 [95% CI: 4.4-11.0] cases per 1000 patient-days; post-outbreak termination endemic rate, 1.1 (95% CI: 0.4-2.3) cases per 1000 patient-days). The rate ratio comparing the outbreak and the baseline period was 3.20 (95% CI: 1.40-7.95, P = .002); the rate ratio comparing the post-outbreak period with the baseline period was 0.48 (95% CI: 0.14-1.53, P = .10), and it has not been necessary to screen personnel for MRSA carriage to prevent nosocomial MRSA infections in this highly vulnerable population.. Preemptive barrier precautions were highly effective in controlling the outbreak and, most notably, have also been highly effective in maintaining a very low incidence of nosocomial MRSA infection endemically in the succeeding 27 months of follow-up. Use of clean gloves, with or without a gown, bears consideration for all high-risk hospitalized patients to prevent cross transmission of all multiresistant nosocomial pathogens.

Topics: Burn Units; Carrier State; Cross Infection; Deoxyribonucleases, Type II Site-Specific; Disease Outbreaks; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genotype; Humans; Incidence; Infection Control; Infectious Disease Transmission, Professional-to-Patient; Methicillin Resistance; Molecular Epidemiology; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus; Wisconsin

The purpose of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and to define risk factors allowing identification of high-risk patients for MRSA nasal carriage at admission to the vascular surgery unit. From March 23, 2004 to July 13, 2004, screening for nasal carriage of MRSA was conducted at admission to the vascular surgery unit and 1 week thereafter. To analyze risk factors for MRSA nasal carriage at admission to the vascular surgery unit, a case-control study was carried out in patients presenting colonization at the time of admission. A total of 308 patients underwent nasal screening for MRSA. Thirteen were colonized with MRSA (nine at admission and four acquired), i.e., 4.2% of patients. Methicillin-susceptible Staphylococcus aureus (MSSA) was found in 11.4% of patients who underwent screening. Six patients with MRSA infection were identified during the study period. The two patients who acquired infection were colonized at the time of admission. Arrival from another health-care facility and from another department was a significant risk factor for carriage of MRSA. The prevalence of nasal carriage in vascular surgery was 4.2%. Nasal screening is highly cost-effective since 60% of MRSA carriers were undetected using diagnostic specimens alone. French recommendations issued for cardiac and orthopedic surgery by the consensus conference on preoperative management of infectious risk on March 5, 2004, should be extended to vascular surgery.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Case-Control Studies; Cross Infection; Female; France; Humans; Infection Control; Male; Mass Screening; Methicillin Resistance; Middle Aged; Nose; Patient Admission; Practice Guidelines as Topic; Prevalence; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgery Department, Hospital; Vascular Surgical Procedures

This study aimed (a) to provide information on methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) Staphylococcus aureus colonization ratio in residents of nursing homes; (b) to determine the effect of hand-washing education given to nursing home residents and employees on nasal carriage of Staphylococcus aureus (NCSA) and (c) to obtain probable risk factors for MRSA colonization of residents in two nursing homes.. Seventy-nine volunteers (24 females and 55 males) from Bolu nursing homes were included in the study. Nasal samples were taken with sterile swabs from the anterior nares. Staphylococcus aureus strains were identified using classical methods and genotyping of methicillin resistant strains was done using Arbitrary Primed PCR (AP-PCR). Antibiotic susceptibilities were determined by disk diffusion methods according to NCCLS standards. After first nasal samples were taken, all employees and residents of nursing homes were educated about the methods of hand hygiene over two days.. With hand-washing education, the decrease of NCSA rate (initially 43%; after education, 21%) was significant (p < 0.05) while decrease of MRSA carriage (initially 5%, after education 1%) was not (p > 0.05). MRSA carriage was significantly correlated with presence of skin lesions, prior hospitalization within the last six months, and antibiotics usage within the last six months. AP PCR results suggested that residents' carriage of MRSA was the result of the same source.. MSSA and MRSA colonization rates were found to be 38% and 5% in nursing homes, respectively. These ratios can decrease with simple precautions like hand-washing after a short education period

Topics: Aged; Aged, 80 and over; Cross Infection; Female; Hand Disinfection; Humans; Inservice Training; Male; Methicillin Resistance; Middle Aged; Nose; Nursing Homes; Polymerase Chain Reaction; Program Evaluation; Risk Assessment; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Turkey

The frequency of nasal staphylococcal colonization among haemodialysed patients was investigated. The swabs were collected in 1998 and 2004 from 28 and 43 patients, respectively. Staphylococcus aureus colonization rates were 57.1% and 27.9% in 1998 and 2004, respectively. Twenty-six coagulase-negative staphylococci (CNS) isolates were cultured: S. epidermidis (21), S. lugdunensis (2), single S. haemolyticus, S. warneri, and S. capitits isolates. One S. aureus and 10 CNS isolates were methicillin resistant. The methicillin-resistant S. aureus (MRSA) was resistant to beta-lactams, tetracycline, and harbored the pvl gene encoding the Panton-Valentine leukocidin. The decrease in S. aureus colonization at 6-year interval was observed. The presence of the pvl gene and a favorable antibiotic susceptibility pattern of the MRSA suggest that the isolate was a member of community-acquired MRSA (CA-MRSA). Concluding, screening of haemodialysed patients for staphylococcal colonization accompanied by characterization of cultured isolates is important to understand its epidemiology and to develop infection prevention measures and treatment strategies.

Topics: Carrier State; Coagulase; Community-Acquired Infections; DNA, Bacterial; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is the most common cause of healthcare-associated infections. Intranasal mupirocin treatment probably decreases S. aureus infections among colonized surgical patients. Using cost-effectiveness analysis, we evaluated the cost-effectiveness of preoperative use of mupirocin for the prevention of healthcare-associated S. aureus infections.. Three strategies were compared: (1) screen with nasal culture and give treatment to carriers, (2) give treatment to all patients without screening, and (3) neither screen nor treat. A societal perspective was taken. Adverse outcomes included bloodstream infection, pneumonia, surgical site infection, death due to underlying illness or infection, readmission, and the need for home health care. Data inputs were obtained from an extensive MEDLINE review and from publicly available government data sources. The following base-case data inputs (and ranges) for sensitivity analysis were used: rate of S. aureus carriage, 23.1% (19%-55%); efficacy of mupirocin treatment, 51% (8%-75%); mupirocin treatment cost, 48.36 US Dollars (24.18-57.74 US Dollars); and hospital costs of bloodstream infection, 25,128 US Dollars (6,194-40,211 US Dollars), pneumonia, 18,366 US Dollars (5,574-28,952 US Dollars), and surgical site infection 16,256 US Dollars (5,119-22,553 US Dollars). Widespread use of mupirocin has been associated with high levels of mupirocin resistance; therefore, a broad range of estimates for efficacy was tested in the sensitivity analysis.. The target population included patients undergoing nonemergent surgery requiring postoperative hospitalization.. Both the screen-and-treat and treat-all strategies were cost saving, saving 102 US Dollars per patient screened and 88 US Dollars per patient treated, respectively. In 1-way sensitivity analyses, the model was robust with respect to all data inputs except for the efficacy of mupirocin treatment. If the efficacy is less than 16.1%, then the screen-and-treat strategy is cost incurring. A treat-all strategy was more cost saving if the rate of S. aureus carriage was greater than 42.7%, the mupirocin cost was less than 29.87 US Dollars, or nursing compensation was greater than 64.21 US Dollars per hour.. Administration of mupirocin before surgery is cost saving, primarily because healthcare-associated infections are very expensive. The level of mupirocin efficacy is critical to the cost-effectiveness of this intervention.

Topics: Anti-Bacterial Agents; Cost Savings; Cost-Benefit Analysis; Cross Infection; Decision Trees; Mupirocin; Nose; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Nasal carriage of Staphylococcus aureus is often a prelude to infection with the same strain. The prevailing assumption has been that colonized individuals carry a single strain. The present study investigated the frequency of simultaneous nasal carriage of multiple strains of S. aureus. Three bacterial colonies from plated samples from colonized subjects were initially compared by pulsed-field gel electrophoresis. Fourteen of 148 S. aureus-positive samples demonstrated at least a difference of a single band; 7 of these 14 samples contained different strains, and 3 of these 7 also belonged to different accessory gene regulator (agr) types. The remaining 7 samples contained clonally related isolates; 3 of these 7 contained pairs that differed by the presence or absence of the staphylococcal chromosomal cassette mec type IV. A mathematical model that we developed predicted that approximately 6.6% of S. aureus-colonized individuals carry >1 strain. The present study demonstrates that carriage of discordant S. aureus strains in individuals with nasal colonization occurs regularly and suggests that the nares are likely sites for horizontal genetic exchange among strains.

Topics: Adult; Anti-Bacterial Agents; Bacterial Typing Techniques; Carrier State; Female; Humans; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Models, Statistical; Nose; Staphylococcal Infections; Staphylococcus aureus

A total of 1,838 subjects from the community and 393 subjects from health care-related facilities in Taiwan were evaluated for the prevalence of nasal Staphylococcus aureus colonization and to identify risk factors associated with S. aureus and methicillin-resistant S. aureus (MRSA) colonization. Among the community subjects, 3.5% had nasal MRSA colonization. Subjects from health care-related facilities had a lower S. aureus colonization rate (19.1%) than community subjects (25.2%) but had a significantly higher rate of colonization with MRSA (7.63%). Age (P < 0.001) was a significant risk factor for S. aureus colonization, with subjects under age 20 years or between 71 and 80 years showing higher rates of colonization. Recent gastrointestinal disease (P = 0.011) and hospital admission (P = 0.026) were risk factors for nasal MRSA colonization. Comparison of hospital MRSA isolates with the colonization strains by staphylococcal cassette chromosome mec (SCCmec) gene typing and pulsed-field gel electrophoresis (PFGE) typing revealed that most MRSA strains carried in the community were SCCmec type IV and that most clinical hospital isolates were type III, while health care facility-related carriage isolates were mainly SCCmec type III and type IV. Two new variant SCCmec types were identified. Six clusters of PFGE patterns were distinguished: two mainly comprised health care facility-related MRSA strains, three mainly comprised community MRSA strains, and one comprised mixed community and health care facility-related MRSA strains. In conclusion, a high prevalence of MRSA colonization was observed among people with no relationship to the hospital setting. The high level of multiple-drug resistance among community MRSA strains in association with the previously reported excessive use of antibiotics in Taiwan highlights the importance of the problem of antibiotic selective pressure. Our results indicate that both the clonal spread of MRSA and the transmission of hospital isolates contribute to the high MRSA burden in the community.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

The aim of this study was to measure the rate of Staphylococcus aureus nasal colonization among attendees of the 13th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), particularly with regard to methicillin-resistant (MRSA) strains. The 31.4% rate of Staphylococcus aureus colonization detected among the participants was in line with colonization rates reported previously for healthcare workers. A statistical difference was found between the rates of Staphylococcus aureus carriage in physicians (37.4%) and non-physicians (21.7%) but not between males (35.0%) and females (28.9%). Only one participant (a Belgian physician) was found to carry MRSA. Surprisingly, the rate of methicillin-susceptible Staphylococcus aureus carriage was significantly higher among participants from countries with a low prevalence of MRSA.

Topics: Carrier State; Communicable Diseases; Congresses as Topic; Europe; Female; Health Personnel; Humans; Male; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infection after orthotopic liver transplantation (OLT). Colonization with MRSA is associated with a higher risk of infection. Previous studies have shown a high prevalence of MRSA colonization among OLT candidates. However, the risk of colonization with MRSA after OLT is still unclear. The objective of this study was to estimate the incidence and the factors associated with colonization with MRSA after OLT. This was a prospective cohort study including patients submitted to OLT between the years 2000 and 2002. Surveillance cultures of nasal swab specimens were performed within the 1st 72 hours of hospital admission and, subsequently, on weeks 2, 6, 13, and 26. Patients whose baseline cultures revealed nasal carriage of MRSA were excluded. A total of 60 patients were included in the study. The median follow-up was 72 days. A total of 9 patients (15%) became colonized. In multiple logistic regression analyses, the use of a urinary catheter for > or =5 days (P = .006), postoperative bleeding at the surgical site (P = .009), and preoperative use of fluoroquinolones (P = .08) were associated with a higher risk of colonization. Patients without any of these risk factors did not become colonized. In conclusion, nasal carriage of MRSA is frequently acquired after OLT. Periodic postoperative screening for MRSA carriage should be an integral component in programs designed to reduce nosocomial MRSA transmission in these patients. Further studies are needed to set up and validate a predictive model that could allow targeting postoperative screening to high-risk OLT recipients.

Topics: Female; Humans; Incidence; Length of Stay; Liver Transplantation; Logistic Models; Male; Methicillin Resistance; Middle Aged; Nose; Postoperative Complications; Staphylococcal Infections; Staphylococcus aureus

Infection-control strategies usually combine several interventions. The relative value of individual interventions, however, is rarely determined. We assessed the effect of daily microbiological surveillance alone (e.g., without report of culture results or isolating colonized patients) as an infection-control measure on the spread of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in a medical intensive care unit (MICU).. Colonization of patients with MSSA and MRSA was assessed by cultures of nasal swabs obtained daily and, if a patient was intubated, by cultures of additional endotracheal aspirates. Pulsed-field gel electrophoresis was used to determine relatedness between MSSA or MRSA isolates in surveillance cultures (i.e., cultures of nasal swab specimens obtained daily) and those in clinical cultures (i.e., any other culture performed for clinical purposes). Adherence to infection-control measures by health care workers (HCWs) was determined by observations of HCW-patient interaction.. During a 10-week period, surveillance cultures were performed for 158 patients. Fifty-five patients (34.8%) were colonized with MSSA, and 9 (5.7%) were colonized with MRSA. Sixty-two patients were colonized before admission to the hospital (53 had MSSA, and 9 had MRSA). Two patients appeared to have acquired MSSA in the MICU, but, on the basis of genotyping analysis, we determined that this was not the result of cross-acquisition.. Surveillance cultures and genotyping of MRSA and MSSA isolates demonstrated the absence of cross-transmission among patients in the MICU, despite ongoing introduction of these pathogens. Reporting culture results and isolating colonized patients, as suggested by some guidelines, would have falsely suggested the success of such infection-control policies.

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Humans; Infection Control; Methicillin Resistance; Nose; Patient Isolation; Staphylococcal Infections; Staphylococcus aureus

The vitamin D endocrine system has been shown to influence the immune response and polymorphisms in the vitamin D receptor (VDR) gene have been associated with susceptibility to infectious diseases. We determined if the Cdx2, FokI and BsmI-ApaI-TaqI polymorphisms in the VDR gene were associated with nasal carriage of Staphylococcal aureus. We defined the S. aureus nasal carriage status (persistent, intermittent or non-carriage) for a group of more that 2000 elderly volunteers. The prevalence of persistent S. aureus nasal carriage was 18%, which was, however, not associated with any of the variant VDR genotypes. Our study into genetic determinants of S. aureus carriage patterns is the largest in the field, but still we found no association between VDR gene variation and S. aureus nasal carriage.

Topics: Aged; Carrier State; DNA; DNA Restriction Enzymes; Female; Genotype; Humans; Male; Middle Aged; Nose; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Receptors, Calcitriol; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus recovered from nasal carriers, producers and non-producers (43 isolates each) of classical pyrogenic toxin superantigens (PTSAgs), were screened for 17 additional PTSAg-genes by PCR. Percentages of 88.4 and 65.1 were positive for some new enterotoxin-gene, and 76.7 and 55.8 for enterotoxin-gene-clusters (egc-like), respectively. The 86 isolates belonged to 17 toxin-genotypes (all eta-, etb-, etd-, see- and sep-negative), and generated 40 SmaI-genomic profiles that in a dendrogram of similarity (S0.7) clustered into nine lineages and 11 non-clustered branches. Correlations between classical PTSAgs and SmaI-lineages were established and egc-like groupings appeared dispersed in six lineages.

Topics: Bacterial Toxins; Carrier State; Deoxyribonucleases, Type II Site-Specific; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Humans; Nose; Polymerase Chain Reaction; Restriction Mapping; Spain; Staphylococcal Infections; Staphylococcus aureus; Superantigens

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of infections outside of health care settings. We investigated an outbreak of abscesses due to MRSA among members of a professional football team and examined the transmission and microbiologic characteristics of the outbreak strain.. We conducted a retrospective cohort study and nasal-swab survey of 84 St. Louis Rams football players and staff members. S. aureus recovered from wound, nasal, and environmental cultures was analyzed by means of pulsed-field gel electrophoresis (PFGE) and typing for resistance and toxin genes. MRSA from the team was compared with other community isolates and hospital isolates.. During the 2003 football season, eight MRSA infections occurred among 5 of the 58 Rams players (9 percent); all of the infections developed at turf-abrasion sites. MRSA infection was significantly associated with the lineman or linebacker position and a higher body-mass index. No MRSA was found in nasal or environmental samples; however, methicillin-susceptible S. aureus was recovered from whirlpools and taping gel and from 35 of the 84 nasal swabs from players and staff members (42 percent). MRSA from a competing football team and from other community clusters and sporadic cases had PFGE patterns that were indistinguishable from those of the Rams' MRSA; all carried the gene for Panton-Valentine leukocidin and the gene complex for staphylococcal-cassette-chromosome mec type IVa resistance (clone USA300-0114).. We describe a highly conserved, community-associated MRSA clone that caused abscesses among professional football players and that was indistinguishable from isolates from various other regions of the United States.

Topics: Abscess; Adult; Clone Cells; Cohort Studies; Community-Acquired Infections; Disease Outbreaks; Electrophoresis, Gel, Pulsed-Field; Football; Gels; Humans; Hydrotherapy; Male; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Retrospective Studies; Risk Factors; Skin; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; United States

We investigated the impact of staphylococcal carriage among patients on continuous peritoneal dialysis (CPD) in a university hospital.. Patients were screened for Staphylococcus aureus carriage and categorized as persistent, intermittent, or non-S. aureus nasal carriers. Patients were subsequently recultured every 12 weeks for S. aureus and coagulase negative staphylococcal (CoNS) carriage, and followed-up for CPD-related infections and antibiotic resistance.. Fifty-two patients were included: 20 peristent, 10 intermittent, and 22 non-S. aureus carriers. Only persistent S. aureus carriage was significantly associated with an increased risk for all CPD-related infections [incidence rate ratio (IRR) 3.52 (95% CI: 2.56-4.85)], exit site infections [IRR 5.59 (95% CI: 3.50-8.92)], and peritonitis [IRR 2.19 (95% CI: 1.39-3.45)], as well as increased antibiotic use [IRR 3.43 (95% CI: 2.50-4.72)], including vancomycin [IRR 2.15 (95%: 2.13-2.16)]. No vancomycin-resistant S. aureus strains were detected. However, eight (2%) out of 407 CoNS strains isolated were vancomycin intermediately susceptible. In all five patients (four persistent and one intermittent carriers) concerned, this was significantly related to a higher antibiotic (including vancomycin) usage [IRR 2.65 (95% CI: 1.82-3.84)].. Persistent-but not intermittent-S. aureus nasal carriage is the major determinant of CPD-related infections, and is associated with a significantly higher consumption of antibiotics, including vancomycin. The highly diverse population of CoNS appears to be the prime reservoir of staphylococcal vancomycin resistance. Accurate determination of the S. aureus nasal carriage state of CPD patients is essential to better target intervention strategies to prevent CPD-related infections.

Topics: Adult; Aged; Carrier State; Drug Resistance, Bacterial; Female; Follow-Up Studies; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis; Staphylococcal Infections; Staphylococcus aureus; Vancomycin Resistance

We sought to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among emergency department (ED) patients with skin and soft tissue infections, identify demographic and clinical variables associated with MRSA, and characterize MRSA by antimicrobial susceptibility and genotype.. This was a prospective observational study involving a convenience sample of patients who presented with skin and soft tissue infections to a single urban public hospital ED in California. Nares and infection site cultures were obtained. A health and lifestyle questionnaire was administered, and predictor variables independently associated with MRSA were determined by multivariate logistic regression. All S aureus isolates underwent antibiotic susceptibility testing. Eighty-five MRSA isolates underwent genotyping by pulsed field gel electrophoresis, staphylococcal chromosomal cassette mec (SCC mec ) typing, and testing for Panton-Valentine leukocidin genes.. Of 137 subjects, 18% were homeless, 28% injected illicit drugs, 63% presented with a deep or superficial abscess, and 26% required admission for the infection. MRSA was present in 51% of infection site cultures. Of 119 S aureus isolates (from infection site and nares), 89 (75%) were MRSA. Antimicrobial susceptibility among MRSA isolates was trimethoprim/sulfamethoxazole 100%, clindamycin 94%, tetracycline 86%, and levofloxacin 57%. Among predictor variables independently associated with MRSA infection, the strongest was infection type being furuncle (odds ratio 28.6). Seventy-six percent of MRSA cases fit the clinical definition of community associated. Ninety-nine percent of MRSA isolates possessed the SCC mec IV allele (typical of community-associated MRSA), 94.1% possessed Panton-Valentine leukocidin genes, and 87.1% belonged to a single clonal group (ST8:S).. In this urban ED population, MRSA is a major pathogen in skin and soft tissue infections. Although studies from other practice settings are needed, MRSA should be considered when empiric antibiotic therapy is selected for such infections.

Topics: Adolescent; Adult; California; Carrier State; Community-Acquired Infections; Emergency Service, Hospital; Female; Furunculosis; Genotype; Humans; Logistic Models; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Odds Ratio; Prevalence; Prospective Studies; Soft Tissue Infections; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Urban Health

Nasal carriage is a major risk factor for Staphylococcus aureus infection, especially for methicillin-resistant strains (MRSA). Using a mouse model of nasal carriage, we have compared several S. aureus strains and demonstrated increased colonization levels by MRSA in cystic fibrosis transmembrane conductance regulator-deficient mice and Toll-like receptor 2 (TLR2)-deficient mice but not TLR4-deficient mice.

Topics: Animals; Carrier State; Colony Count, Microbial; Female; Humans; Methicillin Resistance; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred CFTR; Mice, Knockout; Nose; Receptors, Cell Surface; Staphylococcal Infections; Staphylococcus aureus; Toll-Like Receptor 2; Toll-Like Receptor 4

The purpose of this study was to assess the prevalence of Staphylococcus aureus nasal carriage of dairy sheep in farms producing cheeses manufactured with raw ewe's milk. The study showed that 29% of ewes carried S. aureus in their nares. The genetic diversity of the 136 isolates recovered from the anterior nares of the ewes, from the ambient air of the milking parlour and from cheeses was investigated using pulsed-field gel electrophoresis (PFGE) of DNA SmaI digests. The genotyping results showed that 75 out of 106 isolates recovered from nasal carriage in dairy sheep belonged to a dominant pattern (previously named OV) and a genetically related pattern (named OV'). The same profile (OV or OV') was found in the ambient air and cheeses, suggesting a continuum between isolates within these different compartments.

Topics: Air Microbiology; Animals; Carrier State; Cheese; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; France; Genetic Variation; Genotype; Nose; Prevalence; Sheep; Sheep Diseases; Staphylococcal Infections; Staphylococcus aureus

Persons with acquired immune deficiency syndrome (AIDS) who use drugs appear to be at increased risk for colonization and infection with Staphylococcus aureus. Little is known about the nature of and risk factors responsible for this association. This study is among the first to prospectively follow carriage and infection in this uniquely high-risk population.. We prospectively followed the cases of 75 patients with AIDS in a residential drug treatment facility and screened for S. aureus nasal colonization and infection.. Thirty-seven baseline cultures (49%) were positive for S. aureus, and 81% of subjects were colonized at least once during the study. Thirteen subjects experienced 17 infections. Pulsed-field gel electrophoresis and sequence-based typing methods revealed that 244 (92%) of the isolates belonged to either clonal type A or B. Clonal type A was methicillin-susceptible. Clonal type B consisted of 3 main subtypes (B1, B2, and B3), all with the same allelic profile (ST8) and staphylococcal protein A gene (spa) type (7). Of note, subtype B1 was methicillin-susceptible (ST8 and spa type 7), lacking mecA, whereas the other B clones were methicillin-resistant. Both clones were resistant to trimethoprim-sulfamethoxazole. Clonal type B isolates were relatively resistant, suggesting prior exposure to the health care setting.. This study demonstrates a sustained high rate of S. aureus carriage and infection. It demonstrates the capacity of unique methicillin-resistant S. aureus clones with an established linkage to earlier outbreaks of methicillin-resistant S. aureus, as well as to human immunodeficiency virus--infected subjects, to persist in this residential setting. It also illustrates the apparent genetic instability or transmissibility of the staphylococcal chromosomal cassette mec type IV element.

Topics: Acquired Immunodeficiency Syndrome; Adult; Anti-Bacterial Agents; Carrier State; Drug Resistance, Bacterial; Female; Genotype; Humans; Male; Middle Aged; Molecular Epidemiology; Nose; Phenotype; Phylogeny; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Carrier State; Humans; Models, Biological; Models, Statistical; Nose; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus exhibits varying degrees of reduced vancomycin susceptibility, and strains with intermediate levels of resistance are thought to emerge by antibiotic selection of subpopulations in heterogeneously resistant precursor strains exposed to this antibiotic. We sought to determine the prevalence of and risk factors for carriage of potential heterogeneous vancomycin-intermediate S. aureus (hVISA).. We prospectively observed a cohort of 211 patients undergoing hemodialysis and performed quarterly surveillance cultures for up to 2 years. We screened for reduced vancomycin susceptibility using brain-heart infusion agar with 4 microg/mL vancomycin.. We identified 10 colonizing potential hVISA isolates recovered from 7 patients among both methicillin-susceptible and methicillin-resistant S. aureus strains. No confirmed hVISA isolates were identified; we can be 95% certain that the prevalence of confirmed hVISA carriage does not exceed 1.4%. When compared with noncolonized hemodialysis patients, neither vancomycin exposure, duration of hospitalization, nor any baseline clinical or demographic factor was found to predict colonization with potential hVISA on univariate analyses; increased number of months receiving hemodialysis was associated with potential hVISA colonization on multivariate analysis.. Despite numerous published reports of S. aureus with reduced vancomycin susceptibility, carriage of these isolates remains a rare phenomenon. Given the unclear clinical significance of potential hVISA, it is not clear whether clinical laboratories should identify such strains, or how they should do so.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Cohort Studies; Drug Resistance, Bacterial; Female; Humans; Male; Middle Aged; Nose; Prevalence; Prospective Studies; Renal Dialysis; Risk Factors; San Francisco; Staphylococcal Infections; Staphylococcus aureus; Vancomycin

We describe a comprehensive detection system for 18 kinds of classical and newly described staphylococcal superantigenic toxin genes using four sets of multiplex PCR. Superantigenic toxin genotyping of Staphylococcus aureus for 69 food poisoning isolates and 97 healthy human nasal swab isolates revealed 32 superantigenic toxin genotypes and showed that many S. aureus isolates harbored multiple toxin genes. Analysis of the relationship between toxin genotypes and toxin genes encoding profiles of mobile genetic elements suggests its possible role in determining superantigenic toxin genotypes in S. aureus as combinations of toxin gene-encoding mobile genetic elements.

Topics: Bacterial Typing Techniques; DNA Transposable Elements; Enterotoxins; Genotype; Humans; Nose; Polymerase Chain Reaction; Staphylococcal Food Poisoning; Staphylococcal Infections; Staphylococcus aureus; Superantigens

Until recently, infections with methicillin-resistant Staphylococcus aureus (MRSA) have mainly been associated with hospital outbreaks in Norway. However, increasingly cases are contracted outside hospitals. This paper reports the first two outbreaks of MRSA in two nursing homes in central Norway, affecting 23 residents and five staff members. Pulsed-field gel electrophoresis analysis showed that all strains from nursing home A were identical and that the strains from nursing home B were genotypically similar with one or two band differences. Multi-locus sequence typing (MLST) showed that the strains from the two nursing homes belong to clonal complex 45, with each strain being a single-locus variant of sequence type 45 (ST 45), a well-known European epidemic strain. No evident source of the two outbreaks was found, and there was no obvious connection between the two outbreaks. The latter is also supported by the minor differences observed by MLST, suggesting a connection at some time in the past. The outbreaks led to a heavier workload and economic strain on both nursing homes. The outbreak in nursing home A was brought to an end, whereas two residents remained colonized in nursing home B despite several eradication attempts. These outbreaks show the potential for MRSA spread in a nursing home. If the prevalence of MRSA in Norway continues to increase, nursing home staff and residents may have to be included in the groups to be screened for MRSA upon hospital admission.

Topics: Aged; Aged, 80 and over; Cross Infection; Disease Outbreaks; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genotype; Humans; Methicillin Resistance; Molecular Epidemiology; Norway; Nose; Nursing Homes; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Suppuration; Wounds and Injuries

Surveillance cultures performed at hospital admission have been recommended to identify patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) but require substantial resources. We determined the prevalence of and risk factors for MRSA colonization at the time of hospital admission among patients cared for at a public urban hospital.. Anterior nares cultures were obtained within 48 h after admission during a 1-month period. A case-control study and molecular typing studies were performed.. A total of 53 (7.3%) of 726 patients had a nares culture positive for MRSA, and 119 (16.4%) had a nares culture that was positive for methicillin-susceptible S. aureus. In multivariate analysis, risk factors for MRSA colonization included antibiotic use within 3 months before admission (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.2-5.0), hospitalization during the past 12 months (OR, 4.0; 95% CI, 2.0-8.2), diagnosis of skin or soft-tissue infection at admission (OR, 3.4; 95% CI, 1.5-7.9), and HIV infection. A total of 47 (89%) of 53 case patients colonized with MRSA had at least 1 of these independent risk factors, in contrast to 343 (51%) of 673 control patients (OR, 7.5; 95% CI, 3.2 -17.9). Molecular typing demonstrated that 16 (30%) of 53 MRSA nares isolates (2.2% of the 726 isolates) belonged to the USA300 community-associated MRSA (CA-MRSA) genotype.. The prevalence of MRSA colonization at the time of patient admission was high (>7%). Limiting surveillance cultures to patients with >or=1 of the identified risk factors may allow for targeted screening. The emergence of CA-MRSA colonization represents a new, unrecognized reservoir of MRSA within hospitals, potentially increasing the risk for horizontal transmission.

Topics: Adolescent; Adult; Case-Control Studies; Community-Acquired Infections; Cross Infection; Female; Hospitals; Humans; Male; Methicillin Resistance; Middle Aged; Multivariate Analysis; Nose; Odds Ratio; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Carrier State; Humans; Methicillin Resistance; Nose; Patient Isolation; Population Surveillance; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Carrier State; Humans; Intensive Care Units; Methicillin Resistance; Nose; Patient Isolation; Staphylococcal Infections; Staphylococcus aureus

Prior studies, including one from our institution performed in 2001, suggest that nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) occurs infrequently in the healthy pediatric population (0.2-2.2%). However, infections caused by community-associated MRSA have increased remarkably in recent years. As a result, we restudied the prevalence of MRSA nasal colonization in healthy children, comparing results from 2001 and 2004.. Nasal swabs were collected from 500 children presenting for health maintenance visits. Samples were cultured quantitatively, and MRSA isolates were confirmed by growth on selective media, coagulase testing and the presence of the mecA resistance gene. MRSA isolates were further analyzed for antibiotic susceptibilities, genetic relatedness by pulsed field gel electrophoresis and polymerase chain reaction for the detection of the gene encoding Panton-Valentine leukocidin.. There were 182 children (36.4%) colonized with S. aureus, and 46 (9.2%) colonized with MRSA. This is significantly higher than the MRSA colonization rate in 2001 (0.8%; P < 0.001). There were no significant associations between potential risk factors and MRSA colonization except for having a family member work in a hospital (odds ratio, 2.0; 95% confidence interval, 1.03-4.1). Pulsed field gel electrophoresis revealed heterogeneity of circulating strains, and the Panton-Valentine leukocidin gene locus was detected in 10 of 46 MRSA isolates (22%).. Nasal MRSA colonization in healthy children in Nashville has increased significantly in the past 3 years. As colonization typically precedes infection, this increase may be a major factor in the emergence of community-associated MRSA as a pathogen of healthy children.

Topics: Adolescent; Bacterial Toxins; Carrier State; Child; Child, Preschool; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Female; Humans; Infant; Leukocidins; Male; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA), regarded as a tenacious pathogen in the hospital, has recently become increasingly prevalent as a community pathogen. We evaluated the prevalence and characteristics of methicillin-resistant staphylococci in the Japanese community by testing nasal samples of 818 children of five day care centers and two kindergartens in three districts. We found that methicillin-resistant staphylococci are already prevalent among healthy children. Among 818 children, 35 children (4.3%) carried MRSA and 231 children (28.2%) carried methicillin-resistant coagulase-negative staphylococci (MRC-NS). The types of staphylococcal cassette chromosome mec (SCCmec) found among 44 MRSA isolates were as follows: type IIa, 11 isolates; type IIb, 19 isolates; and type IV, 14 isolates. The type IIb SCCmec element was a new SCCmec element found in this study. Eleven (25%) strains which belonged to clonal complex 5 (CC5) carried type IIa SCCmec, and they produced type 2 coagulase and toxic shock syndrome toxin 1. They were indistinguishable from health care-associated MRSA (H-MRSA) strains in Japan, represented by strain N315. On the other hand, 33 (75%) strains, most of which belonged to CC78 or CC91, carried small SCCmec elements, such as type IIb or type IV, and they produced type 1 or type 3 coagulase and exfoliative toxin. The data indicated that MRSA clones distinct from H-MRSA have disseminated in healthy children. The fact that MRC-NS strains were prevalent in the community suggested that they might serve as a reservoir for the SCCmec element carried by MRSA strains disseminated in the community.

Topics: Bacterial Proteins; Carrier State; Child Day Care Centers; Child, Preschool; Coagulase; Community-Acquired Infections; Humans; Japan; Methicillin Resistance; Molecular Sequence Data; Nose; Prevalence; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus

The relationship between nasal Staphylococcus aureus carriage and lower respiratory tract infections was studied in 16 critically ill patients. S. aureus strains from nasal and bronchial samples were characterized by pulsed-field gel electrophoresis. In all but one case, nasal and bronchial strains were genetically identical in the same patients.

Topics: Adult; Aged; Bronchitis; Carrier State; Critical Illness; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Male; Middle Aged; Nose; Pneumonia, Staphylococcal; Staphylococcal Infections; Staphylococcus aureus

Early identification of methicillin-resistant Staphylococcus aureus (MRSA) carriers is a major component of an MRSA control programme. The cost and laboratory workload could be markedly reduced by processing multiple swabs from one person in one culture broth (specimen pooling). We evaluated the sensitivity for MRSA detection and the growth rate of pooled swabs compared with individual processing. In total, 1254 swabs from 423 subjects (two to five swabs per subject) were submitted for detection of MRSA. Swabs were suspended in 2-mL volumes of sterile Todd-Hewitt Broth and divided into two 1-mL aliquots. One aliquot of the suspension was processed as a single specimen, and the other aliquot was mixed (pooled) with other suspensions in which swabs from the same patient were suspended. Forty-four (10%) pooled samples were positive for MRSA. Specimens from seven additional patients that were negative when pooled were positive when processed separately. There was no case where the pooled specimen was positive but the separate specimens were negative. The diagnostic sensitivity of pooled surveillance cultures compared with single cultures, when only subjects colonized by MRSA were considered, was 86% and the false-negative rate was 14%. Eighty percent of the pooled positive cultures were detected by the third day and all were detected by the fourth day. Fifty-four percent of the specimens processed separately were detected by the second day and all were detected by the fourth day. Pooling of specimens decreases the sensitivity of MRSA detection compared with processing each swab separately, particularly in swabs with a low number of colony-forming units. In all subjects whose pooled samples were negative but whose swabs examined separately were positive, the swabs examined separately were negative on primary plates and positive only after culturing in enrichment broth.

Topics: Axilla; Bacteriological Techniques; Culture Media; Groin; Health Personnel; Humans; Methicillin Resistance; Nose; Pharynx; Skin; Specimen Handling; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Animals, Domestic; Methicillin Resistance; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires; Zoonoses

To evaluate the relationship between Staphylococcus aureus nasal and tracheal colonization and infection in medical intensive care unit (MICU) patients. The primary outcome was the incidence of S. aureus infection in colonized versus non-colonized patients.. Prospective, observational cohort study. Patients admitted to the MICU during the study period were screened for S. aureus nasal and tracheal colonization by culture and a PCR assay twice weekly. Demographic, clinical, and microbiologic data were collected in the MICU and for 30 days after discharge. PFGE and antibiotic susceptibility testing were performed on all S. aureus nasal, tracheal, and clinical isolates.. Twenty-three percent of patients (47 of 208) were nasally colonized with S. aureus. Twenty-four percent of these patients developed S. aureus infections versus 2% of non-colonized patients (P < .01). Nine of 11 patients with both nasal colonization and infection were infected by their colonizing strain. Two of 47 nasally colonized patients developed an infection with a different strain of S. aureus. Fifty-three percent of intubated patients with nasal colonization (10 of 19) had tracheal colonization with S. aureus as opposed to 4.9% of intubated, non-colonized patients (3 of 61) (P < .01). Parenteral antibiotics were ineffective at clearing nasal colonization. PCR detected S. aureus colonization (nasal and tracheal) within 6.5 hours with a sensitivity of 83% and a specificity of 99%.. The incidence of S. aureus infection was significantly elevated in nasally colonized MICU patients. Techniques to rapidly detect colonization in this population may make targeted topical prevention strategies feasible.

Topics: Anti-Bacterial Agents; Cohort Studies; Cross Infection; Female; Humans; Incidence; Intensive Care Units; Male; Mass Screening; Methicillin Resistance; Middle Aged; New York City; Nose; Polymerase Chain Reaction; Prevalence; Prospective Studies; Risk Factors; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Trachea; Treatment Outcome

Topics: Anti-Bacterial Agents; Carrier State; Community-Acquired Infections; Cross Infection; Humans; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus; United States

We screened 14,008 adult nonsurgical patients for Staphylococcus aureus nasal carriage at hospital admission and assessed them for invasive S. aureus disease and in-hospital mortality. Multilocus sequence typing was performed on endogenous invasive strains and nasal strains of matched asymptomatic carriers to investigate whether virulent clones could be identified in nasal carriers. Clonal complex (CC) 45 was significantly underrepresented (odds ratio [OR], 0.16 [95% confidence interval {CI}, 0.04-0.59]) and CC30 was overrepresented (not statistically significant) among invasive strains (OR, 1.91 [95% CI, 0.91-4.0]). The distribution of CCs of invasive S. aureus strains in noncarriers did not differ from that in carriers. Those infected with S. aureus strains belonging to a CC had higher mortality than those infected with strains not belonging to a CC (P<.05), which indicates the coevolution of S. aureus virulence and spread in humans.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Proteins; Bacterial Typing Techniques; Carrier State; Case-Control Studies; Female; Genotype; Hospital Mortality; Humans; Male; Middle Aged; Nose; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Virulence

Topics: Anti-Bacterial Agents; Carrier State; Humans; Nose; Phenotype; Staphylococcal Infections; Staphylococcus aureus; Vancomycin Resistance

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as an important cause of staphylococcal infections, but there have been little data on whether CA-MRSA causes health care-associated infections.. A case-control study was performed to identify risk factors for prosthetic joint infections (PJI). Antibiograms of isolates associated with PJI were reviewed. Molecular typing of available MRSA isolates was done using pulsed field gel electrophoresis (PFGE). Nares cultures of health care workers who provided care to those orthopedic patients were obtained.. Over a 13-month period (January 2003-January 2004), 9.5% of patients with prosthetic hip (THA) or knee (TKA) joint surgery developed PJI (7 TKA and 2 THA). The mean time to development of PJI was 20 days. Five infections were caused by CA-MRSA and 3 by methicillin-susceptible S aureus; one was culture negative. All CA-MRSA isolates had identical antibiograms (resistant to beta-lactams and erythromycin; susceptible to clindamycin, trimethoprim-sulfamethoxazole, rifampin, gentamicin, levofloxacin, and vancomycin). Molecular typing of 2 available CA-MRSA isolates revealed that these were the USA300 clone; these isolates were PVL+ and carried SCCmec IV. CA-MRSA was not recovered from nares cultures from 31 health care workers. In multivariate analysis, TKA (OR, 8.1; 95% CI: 1.3-48.1) and surgery time >180 minutes (OR, 7.4; 95% CI: 1.4-39.6) were associated with PJI.. We have demonstrated that the CA-MRSA USA300 clone is no longer just a cause of community-acquired infections but has also emerged as a cause of health care-associated infections, causing PJI at our institution.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Case-Control Studies; Community-Acquired Infections; Cross Infection; Female; Health Personnel; Humans; Incidence; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Prosthesis-Related Infections; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Axilla; Carrier State; Cross Infection; Groin; Humans; Infection Control; Methicillin Resistance; Nose; Perineum; Pharynx; Staphylococcal Infections; Staphylococcus aureus

We executed a blanket-use program of intranasal application of mupirocin ointment to control the propagation of methicillin-resistant Staphylococcus aureus (MRSA) that occurred in a thoracic surgery ward of a university hospital. During an intervention of 14 weeks, all patients admitted to the ward for scheduled surgery received the ointment to their nares three times daily for 3 days before surgery, once on return to the ward, and three times weekly for the following 2 weeks. None of 84 patients was newly colonized with MRSA, and the daily rates of patients with MRSA in a recovery room in the ward significantly decreased in the period. We consider that the unselective application of mupirocin ointment is one of the effective measures to control MRSA propagation in a thoracic surgery unit.

Topics: Administration, Intranasal; Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Female; Hospital Units; Hospitals, University; Humans; Infant; Infant, Newborn; Infection Control; Japan; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus; Thoracic Surgery; Tokyo

To compare the prevalence of nasal and oral Staphylococcus aureus in patients with rheumatoid arthritis (RA) with the prevalence in controls with other rheumatic diseases, and to determine predictors of S. aureus carriage and the influence of treatment with anti-tumor necrosis factor-a (anti-TNF-alpha) agents.. Eighty-one patients with RA and 83 other control patients of 2 outpatient rheumatology clinics were cultured for nasal and oral carriage of S. aureus. Quantitative nasal cultures for S. aureus were performed from swabs of the anterior nares, the posterior pharynx, and the soft palate. Information on medications, medical conditions, and risk factors for S. aureus carriage was collected from all participants by a questionnaire and confirmed by chart review.. The S. aureus carriage rate (nasal and/or oral colonization) was 34.6% among RA patients and 32.5% among controls (p = 0.87). Being treated with an anti-TNF-alpha agent plus methotrexate (MTX) was the only independent predictor of S. aureus carriage (OR 3.24, 95% CI 1.16-9.05, p = 0.025). The S. aureus carriage rate among RA patients treated with an anti-TNF-alpha agent plus MTX was 60% (9/15) versus 23.1% (3/13) in RA patients treated with an anti-TNF-alpha agent only (p = 0.049). All S. aureus isolates were susceptible to oxacillin.. The S. aureus carriage rate among patients with RA was not higher than among controls. Treatment with anti-TNF-alpha agents was not associated with an increased S. aureus carriage rate. However, treatment with an anti-TNF-alpha agent plus MTX may predispose patients to S. aureus carriage.

Topics: Adalimumab; Adult; Aged; Anti-Bacterial Agents; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antirheumatic Agents; Arthritis, Rheumatoid; Etanercept; Female; Humans; Immunoglobulin G; Infliximab; Male; Methotrexate; Microbiological Techniques; Middle Aged; Mouth; Nose; Oxacillin; Prevalence; Receptors, Tumor Necrosis Factor; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Tumor Necrosis Factor-alpha

Topics: Adolescent; Adult; Bacterial Toxins; Bacterial Typing Techniques; Community-Acquired Infections; Disease Outbreaks; Electrophoresis, Gel, Pulsed-Field; Exotoxins; Furunculosis; Humans; Leukocidins; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Polymerase Chain Reaction; Skin; Soccer; Soft Tissue Infections; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

We determined the molecular characteristics of methicillin-resistant staphylococci from animals and staff at a small animal and equine hospital. Methicillin-resistant Staphylococcus aureus (MRSA) identical to human EMRSA-15 was found in dogs and hospital staff. In contrast, 5 distinct MRSA strains were isolated from horses but not from hospital staff.

Topics: Animals; Carrier State; Cats; Dogs; Horses; Hospitals, Animal; Humans; Methicillin Resistance; Nose; Perineum; Skin; Staphylococcal Infections; Staphylococcus aureus

We conducted a study among a group of 26 regional pig farmers to determine the methicillin-resistant Staphylococcus aureus prevalence rate and found it was >760 times greater than the rate of patients admitted to Dutch hospitals. While spa-type t108 is apparently a more widespread clone among pig farmers and their environment, we did find other spa-types.

Topics: Agriculture; Animals; Carrier State; Female; Humans; Male; Methicillin Resistance; Nose; Perineum; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Swine; Swine Diseases

Research has shown that athletes are carriers of Staphylococcus aureus during physical activity.. To estimate the mean total plate count of S aureus carried by footballers before and after training at an indoor venue.. Forty Malay and 20 Indian students volunteered to participate. There was also a control group consisting of 40 Malay and 20 Indian students who were not active. The experimental group were active footballers who had played at school or club level. The subjects were healthy and free of skin infection. The experiment was divided into three sessions, with 20 subjects present at each. At each session, the subjects trained for one hour. Swabs were taken from the skin, nose, and ear before and after training. For the control group, swabs were taken only once from the skin, nose, and ear. The swabs were subjected to biochemical tests and then streaked and cultured aerobically in Baird Parker agar plates for 24 hours at 37 degrees C. Black colonies with a clear zone were presumed to be S aureus, and the mean total plate count of the colonies was estimated. Gram staining, catalase, coagulase slide, coagulase tube, acetoin production, o-nitrophenyl beta-D-galactopyranoside (ONPG), and mannitol fermentation tests were used to confirm the colonies as S aureus. A haemolysin test was conducted with human blood to confirm haemolytic activity.. All subjects in the experimental group were carrying S aureus both before and after training. The estimated mean total counts of colonies from the skin, ear, and nose for the Malays before training were 33, 71, and 312 respectively. Counts after training were 21, 44, and 452 respectively. The results for the Indians were 72, 80, and 309 respectively before training and 55, 200, and 466 respectively after training. The positive results for Gram staining, catalase, coagulase slide, coagulase tube, acetoin production, ONPG, and mannitol fermentation tests were 100%, 96%, 95%, 95%, 93%, 93%, and 90% respectively. All subjects in the control group were also carrying S aureus.. All of the players were carriers of S aureus during training. The decrease in total count from the skin for both races may be due to lysozyme activity lysing the bacterial cells. Contamination of the environment with these bacteria may have increased the estimated total plate count in the nose. The experimental group face a higher risk of infection because of lower immunity during training and higher rate of injuries compared with the control group.

Topics: Adolescent; Carrier State; Disease Susceptibility; Ear; Humans; Male; Nose; Skin; Soccer; Staphylococcal Infections; Staphylococcus aureus

This study sought to determine the rate of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage among hospital staff and outpatients. Nasal swabs were obtained from 500 outpatients and 500 hospital staff. Hospital staff were 2.3-fold more likely to carry MRSA than were outpatients (6% vs 2.6%, P = .013).

Topics: Carrier State; Cross Infection; Disease Reservoirs; Humans; Methicillin Resistance; Nose; Outpatients; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus; Turkey

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Cross Infection; Humans; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Cross Infection; Double-Blind Method; Female; Genotype; Hospital Mortality; Humans; Length of Stay; Male; Middle Aged; Mupirocin; Nose; Ointments; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

In the present study, we report data on virulence determinants of Staphylococcus aureus from stable nasal carriers, emphasizing on the genes encoding fibronectin (fnbA, fnbB) and collagen (cna) adhesive molecules. Of the 44 S. aureus isolates included, 32 isolates (16 pairs) were cultured from the anterior nares of 16 healthy carriers, eight isolates (four pairs) were collected from the nose of four patients with recurrent skin infections and four isolates were obtained from the infection site of these patients. The period between the two nasal swabs taken was 3-5 days. The persistency of carriage could be demonstrated by the indistinguishable genotypic characteristics of the S. aureus isolates in each pair. This could be shown by determination of gene polymorphisms of coa gene and the X-region and IgG-binding region encoding segments of spa gene. In addition, the isolates within the pairs showed identical toxin patterns. This was determined by PCR amplification of the genes encoding staphylococcal enterotoxins (SEA to SEJ) and TSST-1. The genotypic properties also yielded an identity between persistent nasal carriage isolates and the corresponding skin infection isolates of the four patients. In addition, all S. aureus nasal and skin infection isolates were positive for gene fnbA, fnbB and cna could be found with a high frequency. Among the 44 isolates investigated, 16 isolates (36.7%) harbored gene fnbB and 21 isolates (47.7%) gene cna. The data in the present study showed a relatively wide distribution of the genes fnb and cna among the investigated isolates, indicating that the persistent carriage of strains harboring these virulence determinants may increase the risk for subsequent invasive infections in carriers.

Topics: Adhesins, Bacterial; Bacterial Adhesion; Bacterial Proteins; Bacterial Toxins; Carrier Proteins; Carrier State; Coagulase; DNA, Bacterial; Enterotoxins; Genes, Bacterial; Humans; Nose; Polymerase Chain Reaction; Polymorphism, Genetic; Staphylococcal Infections; Staphylococcal Protein A; Staphylococcus aureus; Superantigens; Virulence Factors

Nasal carriage of Staphylococcus aureus is considered a source of subsequent infection in health care settings. Utilization of real-time polymerase chain reaction (PCR) for detection of S. aureus has the potential to dramatically affect infection control practice by rapidly identifying S. aureus-colonized patients. We developed and validated the use of real-time PCR for detection of S. aureus colonization in two patient populations. Paired nasal swabs were collected from 299 neonates and from 151 adult patients at Evanston Hospital. One swab was used for culture and the other placed into a bacterial lysis solution containing achromopeptidase. The DNA liberated was used as the template for real-time PCR with primers for the femA gene. SYBR Green was used for amplicon detection. In the neonatal population the sensitivity, specificity, predictive value positive and predictive value negative for culture and PCR was 92% versus 96%, 100% versus 100%, 100% versus 100%, and 98% versus 99%, respectively. In the adults the results were 90% versus 100%, 100% versus 98%, 100% versus 96%, and 95% versus 100%, respectively. Real-time PCR was able to detect S. aureus in 2 hours compared to 1 to 4 days for culture and provided sensitivity equal to or greater than culture.

Topics: Adult; Bacterial Proteins; DNA Primers; Humans; Infant, Newborn; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA), known as a nosocomial pathogen, has been isolated from community-acquired infections since the 1980s. It has been reported that there are carriers of MRSA in the community although the rate of carriers is low and the most important risk factor of community-acquired carriage is hospitalization or referral to healthcare facilities. We attempted to investigate methicillin-resistant and methicillin-susceptible S. aureus colonization, respectively, in nasal and axillary swabs obtained from 500 patients without a history of hospitalization who were admitted to outpatient clinics and from 102 healthcare workers chosen as a control group. Of the patients, 9.4% had nasal S. aureus colonization without methicillin-resistant strains. Of the health care workers, 8.8% had S. aureus colonization without methicillin-resistant strains and only one worker had MRSA. The nasal carriage ratio of S. aureus in children was found to be 19.1% (22 of 115), and that in adults was 6.5% (25 of 385). The difference between the two age groups was determined as statistically significant (P = 0.006).

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Female; Humans; Infant; Male; Methicillin; Methicillin Resistance; Middle Aged; Nose; Outpatients; Staphylococcal Infections; Staphylococcus aureus; Turkey

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen for which the prevalence, risk factors, and natural history are incompletely understood.. In this prospective observational study, we evaluated 812 US Army soldiers to determine the prevalence of and risk factors for CA-MRSA colonization and the changes in colonization rate over time, as well as to determine the clinical significance of CA-MRSA colonization. Demographic data and swab samples from the nares for S. aureus cultures were obtained from participants at the start of their training and 8-10 weeks later. Over this time period, participants were observed prospectively to monitor for soft-tissue infections. S. aureus isolates were characterized by in vitro examination of antibiotic susceptibilities, mecA confirmation, pulsed-field gel electrophoresis, and Panton-Valentine leukocidin (PVL) gene testing.. At the initial sampling, 24 of the participants (3%) were colonized with CA-MRSA, 9 of whom (38%) developed soft-tissue infections during the study period. In contrast, 229 participants (28%) were colonized with methicillin-susceptible S. aureus (MSSA), 8 (3%) of whom developed clinical infections during the same period (relative risk, 10.7; 95% confidence interval, 4.6-25.2; P<.001). At follow-up culture, the CA-MRSA colonization rate dropped to 1.6% without eradication efforts. Previous antibiotic use was a risk factor for CA-MRSA colonization at the initial sampling (P=.03). PVL genes were detected in 66% of 45 recovered CA-MRSA isolates, including all 9 clinical isolates available for analysis. Of subjects hospitalized, 5 of 6 had PVL-positive CA-MRSA infections.. CA-MRSA colonization with PVL-positive strains was associated with a significant risk of soft-tissue infection, suggesting that CA-MRSA may be more virulent than MSSA. Previous antibiotic use may play a role in CA-MRSA colonization.

Topics: Abscess; Adolescent; Adult; Anti-Bacterial Agents; Carrier State; Cellulitis; Community-Acquired Infections; Female; Humans; Male; Methicillin Resistance; Military Personnel; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Virulence Factors

Because of their biofilm-forming capacity, invasive Staphylococcus epidermidis isolates, which cause the majority of nosocomial catheter-related bloodstream infections (BSIs), are thought to be selected at the time of catheter insertion from a population of less virulent commensal strains. This fact allows the prediction that invasive and contaminating strains can be differentiated via detection of virulence-associated genes. However, the hospital environment may pave the way for catheter-related infections by promoting a shift in the commensal bacterial population toward strains with enhanced virulence. The distribution of virulence-associated genes (icaADBC, aap, atlE, bhp, fbe, embp, mecA, IS256, and IS257), polysaccharide intercellular adhesin synthesis, and biofilm formation were investigated in S. epidermidis strains from independent episodes of catheter-related BSIs in individuals who have received bone marrow transplantation (BMT). The results were compared with those obtained for commensal S. epidermidis isolates from hospitalized patients after BMT and from healthy individuals, respectively. The clonal relationships of the strains were investigated by pulsed-field gel electrophoresis. icaADBC, mecA, and IS256 were significantly more prevalent in BSI isolates than in commensal isolates from healthy individuals. However, the prevalence of any of the genes in clonally independent, endogenous commensal strains from BMT patients did not differ from that in invasive BSI strains. icaADBC and methicillin resistance, factors important for the establishment of catheter-related infections, already ensure survival of the organisms in their physiological habitat in the hospital environment, resulting in a higher probability of contamination of indwelling medical devices with virulent S. epidermidis strains. The dynamics of S. epidermidis populations reveal that detection of icaADBC and mecA is not suitable for discriminating invasive from contaminating S. epidermidis strains.

Topics: Adolescent; Adult; Aged; Bacteremia; Bacterial Proteins; Bone Marrow Transplantation; Catheterization, Central Venous; Child; Child, Preschool; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Male; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus epidermidis; Virulence

Dialysis patients, often carriers of Staphylococcus aureus in their nares, are at high risk of S. aureus infections.. We examined whether RNAIII inhibiting peptide (RIP), which interferes with quorum sensing mechanisms, reduces adherence of S. aureus to host cells and to dialysis catheter polymers in vitro. Adherence was tested by spectroscopy using safranin staining, by confocal scanning laser microscopy and by atomic force microscopy.. RIP inhibited bacterial adherence to HaCat and HEp-2 cells and reduced adherence and biofilm formation not only on polystyrene, but also on both polyurethane- and silicone-made dialysis catheters, with a preponderant effect on silicone, to which bacteria were more adherent.. RIP opens a new perspective in anti-S. aureus prophylaxis, particularly in dialysis patients.

Topics: Bacterial Adhesion; Biofilms; Catheters, Indwelling; Cell Line, Tumor; Humans; In Vitro Techniques; Keratinocytes; Kidney Failure, Chronic; Nose; Oligopeptides; Renal Dialysis; Skin; Staphylococcal Infections; Staphylococcus aureus

Topics: Cross Infection; Habits; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Infections with Staphylococcus aureus are a significant problem in patients in liver transplant units. An association between prior nasal carriage with and subsequent infections has been documented previously in liver transplant recipients and patients with cirrhosis. However, the role of decolonization with mupirocin applied intranasally for the prevention of S. aureus infections in these patients has not been determined.. S. aureus nasal carriage was prospectively sought in 70 consecutive liver transplant candidates. Mupirocin two times per day for 5 days was administered to the carriers. Follow-up nasal cultures to document decolonization were performed 5 days after the final application of mupirocin. The primary endpoint was the development of S. aureus infections.. Thirty-one of 70 patients (44%) were found to be nasal carriers and 27 of 31 nasal carriers (87%) were successfully decolonized. However, 12 of 27 patients (37%) successfully decolonized became recolonized with S. aureus, and an additional nine patients who were initially noncarriers became newly colonized with S. aureus during the study period. Despite the use of mupirocin, 16 of 70 patients (23%) developed an infection with S. aureus. No isolate was found to be mupirocin resistant.. Elimination of S. aureus nasal carriage by mupirocin did not prevent S. aureus infections in patients in our liver transplant unit.

Topics: Adult; Aged; Anti-Bacterial Agents; Carrier State; Female; Humans; Liver Transplantation; Male; Methicillin Resistance; Middle Aged; Mupirocin; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

A total of 429 different Staphylococcus aureus isolates encompassing 219 blood isolates and 210 isolates taken from anterior nares were systematically searched by two multiplex PCR-DNA enzyme immunoassays (PCR-DEIA) for exfoliative toxin (ET) genes eta and etb, as well as for the classical members of the pyrogenic toxin superantigen (PTSAg) gene family comprising the staphylococcal enterotoxin (SE) genes sea-see and the toxic shock syndrome toxin 1 gene tst. In addition, a third PCR-DEIA was established to investigate the possession of four recently described SE genes, viz. seg-sej. The most frequent PTSAg/ET genes amplified were seg and sei, which were found strictly in combination in 55.0% of the S. aureus isolates tested. Other frequently detected toxin genes were tst (20.3%), sea (15.9%), and sec (11.2%). Only five isolates harbored ET genes. Regarding the origin of the S. aureus isolates, a significant difference (P = 0.037) was found for the possession of the sed/sej gene combination (10.5% of blood isolates versus 3.3% of nasal strains). Overall, about half of S. aureus isolates tested harbored genes of the classical members of the PTSAg family and ETs (50.8%), whereas 73.0% of S. aureus isolates were toxin gene positive if the recently described SE genes were included. This notable higher prevalence indicates that the possession of PTSAg genes in particular seems to be a habitual feature of S. aureus. Moreover, mainly due to the fixed combinations of seg plus sei, as well as sed plus sej, the possession of multiple PTSAg genes (62.9%) is more frequent than assumed so far.

Topics: Bacteremia; Bacterial Proteins; Blood; DNA, Bacterial; Enterotoxins; Exfoliatins; Humans; Immunoenzyme Techniques; Nose; Polymerase Chain Reaction; Staphylococcal Infections; Staphylococcus aureus; Superantigens

Reports of methicillin-resistant Staphylococcus aureus (MRSA) infection in neonatal intensive care units (NICU) and normal newborn nurseries in Japan were investigated, and various methods of preventing transmission were evaluated. In the late 1980s, MRSA which had spread in adult wards also invaded NICU. Very low birthweight or premature infants had become the targets of MRSA infection and this has now become a serious problem. Recent reports have revealed that 87% of major NICU in Japan have suffered from MRSA infections. However, we have found that preventive measures can greatly reduce the risk of a newborn being infected by a carrier, while also controlling the disease caused by MRSA infection. Recently, MRSA infections in normal newborn nurseries have also become a serious problem in pediatric departments. Methicillin-resistant Staphylococcus aureus which can colonize in the newborn baby just after birth, is passed on to the newborn by carrier medical staff. It was found to be of great importance that infant's mothers hold and nurse their babies immediately after birth, and start breast-feeding while still in the delivery room. Furthermore, the most appropriate and ideal newborn nursery is one where mother and child are roomed together and there is little intervention by the hospital. In neonatal care, it is of utmost importance to treat carriers of MRSA bacteria, and to inhibit the spread of the bacterium in babies by taking standard precautionary measures.

Topics: Breast Feeding; Cross Infection; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Infant, Very Low Birth Weight; Intensive Care Units, Neonatal; Intubation, Intratracheal; Japan; Methicillin Resistance; Nose; Pharynx; Skin; Staphylococcal Infections

During an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in the neonatal intensive care units at two hospitals, we assessed several sites for detection of MRSA colonization. Nasal cultures found 32 of 33 MRSA-colonized patients (97%). Rectal cultures detected 29% of 24 MRSA-colonized patients identified by paired rectal and nasal samples and axillary samples found 22% of 9 MRSA-colonized patients identified by axillary samples paired with nasal swabs. There were no positive umbilical samples.

Topics: Culture Media; Disease Outbreaks; Female; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Male; Methicillin Resistance; Nose; Population Surveillance; Rectum; Staphylococcal Infections; Staphylococcus aureus

To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among patients presenting for hospital admission and to identify risk factors for MRSA colonization.. Surveillance cultures were performed at the time of hospital admission to identify patients colonized with S. aureus. A case-control study was performed to identify risk factors for MRSA colonization.. A tertiary-care academic medical center.. Adults presenting for hospital admission (N = 974).. S. aureus was isolated from 205 (21%) of the patients for whom cultures were performed. Methicillin-sensitive S. aureus was isolated from 179 (18.4%) of the patients, and MRSA was isolated from 26 (2.7%) of the patients. All 26 MRSA-colonized patients had been admitted to a healthcare facility in the preceding year, had at least one chronic illness, or both. In multivariate analyses comparing MRSA-colonized patients with control-patients, admission to a nursing home (odds ratio [OR], 16.5; 95% confidence interval [CI95], 1.4 to 192.1; P = .025) or a hospitalization of 5 days or longer during the preceding year (OR, 3.91; CI95, 1.1 to 13.9; P = .035) were independent predictors of MRSA colonization.. Patients colonized with MRSA admitted to this hospital likely acquired the organism during previous encounters with healthcare facilities. There was no evidence that MRSA colonization occurs commonly among low-risk individuals in this community. These data suggest that evaluation of recent healthcare exposures is essential if true community acquisition of MRSA is to be confirmed.

Topics: Academic Medical Centers; Carrier State; Case-Control Studies; Georgia; Hospitalization; Humans; Methicillin Resistance; Nose; Population Surveillance; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

To define the extent of nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to a tertiary-care hospital.. A blinded, prospective surveillance culture study of patients admitted to the hospital to determine the transmission (acquisition) rate of MRSA. Risk factors associated with the likelihood of MRSA colonization on admission were investigated.. Tertiary-care military medical facility.. All patients admitted to the medicine, surgery, and pediatric wards, and to the medical, surgical, and pediatric intensive care units were eligible for inclusion.. Five hundred thirty-five admission and 374 discharge samples were collected during the study period. One hundred forty-one patients were colonized with methicillin-susceptible S. aureus (MSSA) and 20 patients (3.7%) were colonized with MRSA on admission. Of the 354 susceptible patients, 6 acquired MRSA during the study for a transmission rate of 1.7%. Patients colonized with MRSA on admission were more likely to be older than non-colonized or MSSA-colonized patients, to have received antibiotics within the past year, to have been hospitalized within the prior 3 years, or to have a known history of MRSA. Patients acquiring MRSA had an average hospital stay of 17.7 days compared with 5.3 days for those who did not acquire MRSA. Pulsed-field gel electrophoresis of the 6 MRSA isolates from patients who acquired MRSA revealed 4 distinct band patterns.. Most patients colonized with MRSA were identified on admission samples. Surveillance cultures of patients admitted may help to prevent MRSA transmission and infection.

Topics: Adult; Carrier State; Cross Infection; Female; Hawaii; Hospitalization; Hospitals, Military; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Population Surveillance; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

To assess the prevalence of and the clinical features associated with asymptomatic Staphylococcus aureus colonization in a healthy outpatient population, and to compare the characteristics of colonizing methicillin-resistant S. aureus (MRSA) strains with those of strains causing infection in our community and hospital.. Outpatient military clinics.. Specimens were obtained from the nares, pharynx, and axillae of 404 outpatients, and a questionnaire was administered to obtain demographic and risk factor information. MRSA strains were typed by pulsed-field gel electrophoresis (PFGE) and evaluated for antibiotic susceptibility. Antibiograms of study MRSA strains were compared with those of MRSA strains causing clinical illness during the same time period.. Methicillin-susceptible S. aureus (MSSA) colonization was present in 153 (38%) of the 404 asymptomatic outpatients, and MRSA colonization was present in 8 (2%). Detection of colonization was highest from the nares. No clinical risk factor was significantly associated with MRSA colonization; however, a tendency was noted for MRSA to be more common in men and in those who were older or who had been recently hospitalized. All colonizing MRSA strains had unique patterns on PFGE. In contrast to strains responsible for hospital infections, most colonizing isolates of MRSA were susceptible to oral antibiotics.. MRSA and MSSA colonization is common in our outpatient population. Colonization is best detected by nares cultures and most carriers of MRSA are without apparent predisposing risk factors for acquisition. Colonizing isolates of MRSA are heterogeneous and, unlike nosocomial isolates, often retain susceptibility to other non-beta-lactam antibiotics.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Cross Infection; Female; Hawaii; Hospitals, Military; Humans; Infant; Male; Methicillin Resistance; Middle Aged; Nose; Outpatient Clinics, Hospital; Prevalence; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcs aureus (MRSA) nasal carriage was assessed among healthcare workers caring for elderly patients in contact precautions in geriatric departments. Monthly incidence ranged from 0% to 3.3%. Carriage was observed only among nurses and nursing assistants. MRSA was thus infrequently acquired using precautions and carriage was usually transient.

Topics: Aged; Carrier State; Health Personnel; Hospital Departments; Humans; Incidence; Infection Control; Methicillin Resistance; Nose; Prevalence; Staphylococcal Infections; Staphylococcus aureus

We describe a case of toxic epidermal necrolysis after intranasal application of mupirocin in a 76-year-old woman. The drug was given for eradication of methicillin-resistant Staphylococcus aureus.

Topics: Administration, Intranasal; Aged; Anti-Bacterial Agents; Fatal Outcome; Female; Humans; Methicillin Resistance; Mupirocin; Nose; Staphylococcal Infections; Stevens-Johnson Syndrome

To investigate the rates of Staphylococcus aureus carriage on the hands and in the noses of healthcare workers (HCWs) and the relatedness of S. aureus isolates found in the two sites.. Point-prevalence study.. Department for Thoracic and Cardiovascular Surgery at the University Hospital of Uppsala, Uppsala, Sweden.. Samples were obtained from 133 individuals, 18 men and 115 women, using imprints of each hand on blood agar and a swab from the nose. S. aureus isolates were identified by standard methods and typed by pulsed-field gel electrophoresis.. S. aureus was found on the hands of 16.7% of the men and 9.6% of the women, and in the noses of 33.3% of the men and 17.4% of the women. The risk ratio for S. aureus carriage on the hands with nasal carriage was 7.4 (95% confidence interval, 2.7 to 20.2; P < .001). Among the 14 HCWs carrying S. aureus on their hands, strain likeness to the nasal isolate was documented for 7 (50%).. Half of the HCWs acquired S. aureus on the hands from patients or the environment and half did so by apparent self-inoculation from the nose. Regardless of the source of contamination, good compliance with hand hygiene is needed from all HCWs to protect patients from nosocomial infections. The moderate rate of S. aureus carriage on hands in this setting could be the result of the routine use of alcoholic hand antisepsis.

Topics: Adult; Anti-Infective Agents, Local; Cardiovascular Surgical Procedures; Carrier State; Female; Guideline Adherence; Hand; Hand Disinfection; Hospitals, University; Humans; Infection Control; Male; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus; Surgery Department, Hospital; Sweden; Thoracic Surgical Procedures; Workforce

The role of rectal carriage of Staphylococcus aureus as a risk factor for nosocomial S. aureus infections in critically ill patients has not been fully discerned.. Nasal and rectal swabs for S. aureus were obtained on admission and weekly thereafter until discharge or death from 204 consecutive patients admitted to the surgical intensive care unit and liver transplant unit. Overall, 49.5% (101 of 204) of the patients never harbored S. aureus, 21.6% (44 of 204) were nasal carriers only, 3.4% (7 of 204) were rectal carriers only, and 25.5% (52 of 204) were both nasal and rectal carriers. Infections due to S. aureus developed in 15.7% (32 of 204) of the patients; these included 3% (3 of 101) of the non-carriers, 18.2% (8 of 44) of the nasal carriers only, 0% (0 of 7) of the rectal carriers only, and 40.4% (21 of 52) of the patients who were both nasal and rectal carriers (P - .001). Patients with both rectal and nasal carriage were significantly more likely to develop S. aureus infection than were those with nasal carriage only (odds ratio, 3.9; 95% confidence interval, 1.18 to 7.85; P= .025). By pulsed-field gel electrophoresis, the infecting rectal and nasal isolates were clonally identical in 82% (14 of 17) of the patients with S. aureus infections.. Rectal carriage represents an underappreciated reservoir for S. aureus in patients in the intensive care unit and liver transplant recipients. Rectal plus nasal carriage may portend a greater risk for S. aureus infections in these patients than currently realized.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Critical Illness; Cross Infection; Female; Hospitals, Veterans; Humans; Infection Control; Intensive Care Units; Liver Transplantation; Male; Methicillin Resistance; Middle Aged; Nose; Pennsylvania; Prevalence; Rectum; Risk Factors; Serotyping; Staphylococcal Infections; Staphylococcus aureus

To evaluate the usefulness of an assay using two polymerase chain reaction-based genotyping methods in the practical surveillance of methicillin-resistant Staphylococcus aureus (MRSA).. Nosocomial infection and colonization were surveyed monthly in a university hospital in Japan for 20 months. Genotyping with mec-HVR is based on the size of the mec-associated hypervariable region amplified by polymerase chain reaction. Toxin genotyping uses a multiplex polymerase chain reaction method to amplify eight staphylococcal toxin genes.. Eight hundred nine MRSA isolates were classified into 49 genotypes. We observed differing prevalences of genotypes for different hospital wards, and could rapidly demonstrate the similarity of genotype for outbreak isolates. The incidence of genotype D: SEC/TSST1 was significantly higher in isolates causing nosocomial infections (49.5%; 48 of 97) than in nasal isolates (31.4%; 54 of 172) (P = .004), suggesting that this genotype may represent the nosocomial strains.. The combined use of these two genotyping methods resulted in improved discriminatory ability and should be further investigated.

Topics: Bacterial Toxins; Bacterial Typing Techniques; Carrier State; Complementarity Determining Regions; Cross Infection; Discriminant Analysis; Disease Outbreaks; DNA, Bacterial; Enterotoxins; Exfoliatins; Genotype; Hospitals, University; Humans; Incidence; Infection Control; Japan; Methicillin Resistance; Nose; Polymerase Chain Reaction; Population Surveillance; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Superantigens

Following an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in our acute rehabilitation unit in 1987, all patients except in-house transfers (because of their low prevalence of MRSA colonization) underwent MRSA screening cultures on admission.. To better characterize the current profile of patients with positive MRSA screening cultures at the time of admission to our acute rehabilitation unit, and to determine the relative yield of nares, perianal, and wound screening cultures in this population.. Prospective chart review with ongoing active surveillance for infections associated with the acute rehabilitation unit. The rate of MRSA isolation from one or more body sites increased significantly from 5% (1987-1988) to 12% (1999-2000) (P = .0009) for newly admitted patients and from 0% to 7% (P < .0001) for in-house transfers. A negative nares culture was highly predictive (98%) of a negative perianal culture. Prior history of MRSA infection or colonization and transfer from outside sources were independently associated with positive MRSA screening cultures.. The rate of MRSA isolation from screening cultures of newly admitted patients, including in-house transfers, has increased significantly during the past decade in our acute rehabilitation unit. When paired with nares cultures, perianal cultures were of limited value in this patient population.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Anal Canal; Carrier State; Cross Infection; Disease Outbreaks; Female; Hospital Units; Hospitals, Community; Hospitals, Teaching; Humans; Infection Control; Male; Mass Screening; Methicillin Resistance; Middle Aged; Missouri; Nose; Patient Admission; Population Surveillance; Predictive Value of Tests; Prevalence; Prospective Studies; Rehabilitation; Staphylococcal Infections; Staphylococcus aureus; Wound Infection

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Cross Infection; Drug Resistance, Bacterial; Humans; Mupirocin; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Mupirocin (Mup) has been used extensively to prevent Staphylococcus aureus (SAu) infections in patients undergoing peritoneal dialysis (PD). Resistance to Mup has been reported, but its relevance after long-term use of this drug in PD is unknown. Colonization by SAu was treated with topic Mup in our unit between September 1990 and December 2000. Sensitivity to Mup was tested in 437 strains of SAu isolated from 155 PD patients and 62 dialysis partners. Resistance to Mup was classified as low (minimal inhibitory concentration [MIC] > or = 8 microg/mL) or high (MIC > or = 512 microg/mL) degree. MIC90 was 0.125 microg/mL in 1990 to 1996 (5% low, 0% high-degree resistance), 64 microg/mL in 1997 to 1998 (6.6% low, 8.3% high-degree resistance), and 1,024 microg/mL in 1999 to 2000 (2.3% low, 12.4% high-degree resistance). Mup-resistant SAu were isolated from 25 patients and 13 partners a median of 15 months after starting PD. Resistance was associated frequently with repeated treatments of SAu recolonization, but was detected in 3 cases at the start of PD therapy. The accumulated incidence of SAu exit-site infection in the period 1997 to 2000 was 32.3% in patients colonized by Mup-resistant SAu as compared with 14.5% in those colonized by Mup-sensitive SAu (P = 0.03). Mup-resistant SAu have emerged in a significant proportion of our PD patients and dialysis partners. This emergence has resulted in a moderate, but significant, increase in the risk of SAu exit-site infection and raises concerns about the future of Mup as the therapy of choice for SAu colonization in patients undergoing chronic PD.

Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Humans; Microbial Sensitivity Tests; Mupirocin; Nose; Peritoneal Dialysis; Peritonitis; Staphylococcal Infections; Staphylococcus aureus

Topics: Administration, Intranasal; Anti-Bacterial Agents; Antibiotic Prophylaxis; Cross Infection; Drug Resistance, Bacterial; Humans; Mupirocin; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

It is unclear whether the levels of Staphylococcus aureus colonization of hospital personnel with patient exposure are increased or whether personnel become colonized with more antibiotic-resistant strains. Differences in nasal and hand carriage of S. aureus between medical and nonmedical hospital personnel were examined. No differences in nasal carriage between the two groups were found; however, there was a trend that suggested differences in the rates of hand carriage of S. aureus (18% of nonmedical personnel and 10% of medical personnel). Medical personnel were colonized with more antibiotic-resistant isolates than nonmedical personnel (mean, 2.8 versus 2.1 isolates [P < 0.03]), and the strain profiles indicated that they tended to be more clonal in origin, suggesting that exposure to hospital isolates alters the colonization profile.

Topics: Adult; Cross Infection; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Hand; Humans; Male; Medical Staff, Hospital; Methicillin Resistance; Middle Aged; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus

To evaluate the relationship of nasal or skin Staphylococcus carrier status with identical strains and the development of staphylococcal peritonitis, 59 consecutive peritonitis episodes in patients using a twin-bag system for continuous ambulatory peritoneal dialysis from a single dialysis center were prospectively studied. Dialysate samples and exit-site, nose, and nail swabs from patients and their dialysis partners were obtained on the same day for culture. When bacteria belonging to the same species of the Staphylococcus genus were isolated from dialysate and at least one extraperitoneal anatomic site, pulsed-field gel electrophoresis typing was performed. The bacterial strains isolated from catheter exit site, nose, or nails of each patient and his or her dialysis partner were classified as identical or different. Twenty-seven of the 59 peritonitis episodes (46%) were caused by staphylococci. Nineteen of these 27 patients carried the same Staphylococcus species causing the peritonitis episode at the exit site, nose, or nails, but only 17 patients (63%) carried an identical strain. Four of 5 dialysis partners carried the same Staphylococcus species causing the peritonitis episode at nose or nails, but the strain was identical for only 3 dialysis partners (60%). Four patients and 1 dialysis partner carried unrelated strains of the Staphylococcus species causing the peritonitis episode. The most frequently colonized site with strains identical to that causing the peritonitis episode was the catheter exit site, followed by nose and nails. This finding may be clinically relevant because eradication of Staphylococcus aureus colonizing the catheter exit site may be more important and have a greater likelihood of success than maneuvers directed to more distant locations.

Topics: Carrier State; Dialysis Solutions; Disease Transmission, Infectious; Hand; Humans; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Skin; Staphylococcal Infections; Staphylococcus

The consequences of infection with Staphylococcus aureus can be severe, so strategies for prevention are important. We examined S. aureus isolates from blood and from nasal specimens to determine whether the organisms in the bloodstream originated from the patient's own flora.. In a multicenter study, swabs for culture were obtained from the anterior nares of 219 patients with S. aureus bacteremia. A total of 723 isolates were collected and genotyped. In a second study, 1640 S. aureus isolates from nasal swabs were collected over a period of five years and then compared with isolates from the blood of patients who subsequently had S. aureus bacteremia.. In the multicenter study of S. aureus bacteremia, the blood isolates were identical to those from the anterior nares in 180 of 219 patients (82.2 percent). In the second study, 14 of 1278 patients who had nasal colonization with S. aureus subsequently had S. aureus bacteremia. In 12 of these 14 patients (86 percent), the isolates obtained from the nares were clonally identical to the isolates obtained from blood 1 day to 14 months later.. A substantial proportion of cases of S. aureus bacteremia appear to be of endogenous origin since they originate from colonies in the nasal mucosa. These results provide support for strategies to prevent systemic S. aureus infections by eliminating nasal carriage of S. aureus.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteremia; Bacterial Typing Techniques; Carrier State; Child; Child, Preschool; Cross Infection; Electrophoresis, Gel, Pulsed-Field; Female; Germany; Hospitals, Community; Hospitals, General; Humans; Infant; Male; Methicillin Resistance; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Bacteremia; Carrier State; Cross Infection; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Nasal augmentation rhinoplasty is a common cosmetic procedure. Alloplastic or synthetic materials are frequently used with Silastic, the most commonly used type worldwide. In the Orient, this common procedure has a low complication rate. However, infection and extrusion of the implant through the skin may occur and patients may be reluctant to report the augmentation procedure to the dermatologist. Therefore, the dermatologist needs to be highly suspicious and include this complication in the differential of ulcerated nasal tip nodules.

Topics: Anti-Bacterial Agents; Combined Modality Therapy; Device Removal; Follow-Up Studies; Humans; Male; Middle Aged; Nose; Prostheses and Implants; Prosthesis-Related Infections; Reoperation; Rhinoplasty; Skin Diseases, Bacterial; Skin Ulcer; Staphylococcal Infections; Staphylococcus aureus; Transplantation, Homologous

Staphylococcus aureus is a major cause of severe infection in humans and yet is carried without symptoms by a large proportion of the population. We used multilocus sequence typing to characterize isolates of S. aureus recovered from asymptomatic nasal carriage and from episodes of severe disease within a defined population. We identified a number of frequently carried genotypes that were disproportionately common as causes of disease, even taking into account their relative abundance among carriage isolates. The existence of these ecologically abundant hypervirulent clones suggests that factors promoting the ecological fitness of this important pathogen also increase its virulence.

Topics: Carrier State; Community-Acquired Infections; Cross Infection; Genes, Bacterial; Genetic Variation; Genotype; Humans; Nose; Point Mutation; Recombination, Genetic; Sequence Analysis, DNA; Staphylococcal Infections; Staphylococcus aureus; Virulence

Topics: Biological Evolution; Carrier State; Genes, Bacterial; Humans; Mutation; Nose; Recombination, Genetic; Selection, Genetic; Staphylococcal Infections; Staphylococcus aureus; Virulence

We investigated the role of viridans group streptococci in the prevention of colonization with methicillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units. During a 26-month period at a children's hospital, 207 (49.9%) of 415 newborns were colonized with MRSA by the time of discharge. Two groups of newborns with matching durations of hospitalization were compared with regard to the prevalence of future colonization with MRSA: group 1 (103 patients) did not acquire colonization with viridans group streptococci and group 2 (63 patients) did acquire colonization with viridans group streptococci at birth or by 1 to 2 weeks (age, < or =11 days). The rate of colonization among patients in group 2 (9.5%) was significantly lower than that among patients in group 1 (44.7%; P<.001). No significant difference in patient characteristics (e.g., birth weight, diseases) was observed. These results indicate that viridans group streptococci, as bacteria that formerly occupied the oral cavities in newborns, may inhibit later colonization with MRSA.

Topics: Antibiosis; Humans; Infant, Newborn; Intensive Care Units, Neonatal; Methicillin Resistance; Mouth; Nose; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Streptococcus

To investigate persistent carriage of methicillin-resistant Staphylococcus aureus (MRSA), we conducted a prospective 10-month study of MRSA carriage in previous carriers who were readmitted to our hospital. Four screening specimens, 2 from the skin and 2 from the nares, were obtained within 3 days after admission, in addition to diagnostic specimens requested by physicians. Of the 78 patients included in our study, 31 (40%) were persistent carriers of MRSA, with an estimated median time of 8.5 months to MRSA clearance. In the multivariate analysis, the only factor significantly associated with persistent carriage was the presence of a break in the skin at readmission (odds ratio, 4.34; P=.004); however, a trend was found for admission from a chronic-care institution (odds ratio, 3.65; P=.06). Our data confirm that prolonged carriage of MRSA can occur after hospital discharge, support routine screening for MRSA at readmission of previously MRSA-positive patients, and suggest that a particularly high index of suspicion for MRSA carriage should be maintained if these patients have a break in the skin.

Topics: Adult; Aged; Aged, 80 and over; Carrier State; Female; Hospitals, Urban; Humans; Male; Methicillin Resistance; Middle Aged; Nose; Patient Discharge; Prospective Studies; Risk Factors; Skin; Staphylococcal Infections; Staphylococcus aureus

Topics: Bacteremia; Carrier State; Humans; Methicillin Resistance; Nose; Skin; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus

Topics: Bacteriological Techniques; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Bacteremia; Cost-Benefit Analysis; Humans; Mass Screening; Nose; Staphylococcal Infections; Staphylococcus aureus

The coagulase-negative species Staphylococcus sciuri is widespread in nature and is associated with a variety of domestic and wild animals. However, the occurrence of S. sciuri in dogs has received little attention so far. In the present study, we established the prevalence of S. sciuri in a large population of healthy dogs, and characterized isolated strains. Samples from two mucous membrane sites (anterior nares and mouth), and two hair-coated sites (head and withers) were taken from 122 dogs and inoculated into STS agar, a novel selective medium that was introduced and tested in the study. In total, 116 isolates of S. sciuri were obtained from 488 specimens. S. sciuri was isolated from 56 out of 122 (46%) dogs. The occurrence of S. sciuri in the anterior nares and mouth were significantly higher than those in withers and head. No significant association of S. sciuri occurrence in dogs and factors such as sex, age, and living environment (indoor/outdoor) was found. Out of 56 dogs, which tested positive for S. sciuri, 30 (54%) would have it as a resident flora. Thus, we showed that S. sciuri was frequently present as a part of skin, nasal and oral flora in healthy dogs both as a resident and transient carriage.

Topics: Animals; Carrier State; Colony Count, Microbial; Culture Media; Dog Diseases; Dogs; Female; Male; Mouth; Nose; Prevalence; Sensitivity and Specificity; Skin; Staphylococcal Infections; Staphylococcus; Yugoslavia

A prevalence survey of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage was undertaken on a random sample of adults (aged over 16) resident in the community in Birmingham, UK during 1998. Microbiological samples were taken from the anterior nares at the subjects' general practice or in their home. Information about risk factors for the acquisition of MRSA was obtained via a self-completed questionnaire. A 58% response rate (280/483) was achieved. The prevalence of nasal MRSA colonization was 1.5% [4/274, 95% confidence interval (CI) 0.03-2.9%]. Twenty-three per cent (63/274) of subjects were nasal carriers of S. aureus. Six per cent (4/63) of S. aureus isolates were MRSA and 2 of the 4 MRSA carriers reported previous contact with health facilities. The prevalence of MRSA colonization in the general adult population in Birmingham appears to be low.

Topics: Adolescent; Adult; Age Distribution; Aged; Aged, 80 and over; Carrier State; Community-Acquired Infections; Drug Resistance, Microbial; England; Female; Humans; Male; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Nose; Population Surveillance; Prevalence; Risk Factors; Sampling Studies; Serotyping; Sex Distribution; Staphylococcal Infections; Staphylococcus aureus; Surveys and Questionnaires

Specimens from the nose and throat were collected from 28 long-term haemodialysed patients. Staphylococcus aureus strains were isolated from sixteen patients who been on haemodialysis for over 113 months. Cytokine levels, as well as full blood cell differential counts and cell surface antigens were determined in these patients. The serum concentration of TGF-beta was significantly higher in patients carrying Staphylococcus aureus. CD14 and HLA-DR molecule expression on monocytes, as well as NK cell percentage was significantly different in S. aureus carriers. Our preliminary results suggest that immune status imbalance in haemodialysed patients could be related to the high incidence of S. aureus nasal carriage and infections.

Topics: Adult; Carrier State; Cytokines; Female; Humans; Immunocompromised Host; Leukocyte Count; Lymphocytes; Male; Middle Aged; Nose; Pharynx; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Recent but scarce reports of methicillin-resistant Staphylococcus aureus strains (MRSA) among children without risk factors associated with its acquisition prompted us to investigate its presence in the community.. During the September and October months in 1997, nasal and pharyngeal swabs were obtained from 358 children aged less than five years who attended three day-care centers in the Marianao Area, La Habana City, Cuba. The isolated S. aureus strains were characterized for antimicrobial sensitivity using the Kirby-Bauer method. Methicillin resistance was confirmed by te Oxacillin Salt-Agar Screening-Plate method recommended by the National Committee for Clinical Laboratory Standards.. 18.7% of children were carriers of S. aureus in the upper respiratory tract; 2.2% of children carried MRSA strains. The highest resistance levels corresponded to erythromycin (50.74%) and tetracycline (29.9%). All tested strains were sensitive to ciprofloxacin.. Our results provide evidence on the recovery of MRSA strains among healthy children attending day-care centers and are suggestive of a rapid colonization and spread of these microorganisms in the community.

Topics: Child Care; Child Day Care Centers; Child, Preschool; Cuba; Female; Humans; Male; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Disease Outbreaks; France; Humans; Infectious Disease Transmission, Patient-to-Professional; Intensive Care Units; Nose; Staphylococcal Infections; Staphylococcus aureus; Vancomycin Resistance

We previously showed that children attending an inner city pediatric emergency department were sometimes asymptomatically colonized with clindamycin-susceptible community-acquired methicillin-resistant Staphylococcus aureus (MRSA) and borderline methicillin-resistant S. aureus (BRSA) as well. We wished to ascertain whether healthy children attending an outpatient clinic were colonized with these organisms. Therefore to estimate the prevalence of community-acquired MRSA and BRSA nasal colonization in a well child population, we cultured children attending an inner city pediatric outpatient clinic.. This was a prospective cross-sectional study conducted from January to August, 1999, at a primary care outpatient facility at the University of Chicago. The target population was 500 healthy children < or = 16 years of age who attended this facility to receive well child care.. One hundred twenty-two (24.4%) children were colonized with S. aureus. Three of the 122 (2.5%) S. aureus isolates were MRSA; they came from children who lacked predisposing risk factors and were susceptible to clindamycin, gentamicin, trimethoprim-sulfamethoxazole, rifampin and ciprofloxacin. Two (1.6%) additional S. aureus isolates were BRSA; both children had predisposing risk factors for MRSA colonization. The mecA gene was present in the 3 MRSA isolates and absent in both BRSA isolates.. These data document that a reservoir of asymptomatic MRSA colonization exists among healthy children who lack traditional risk factors for MRSA infections.

Topics: Adolescent; Ambulatory Care; Carrier State; Child; Child, Preschool; Community-Acquired Infections; Cross-Sectional Studies; Female; Humans; Infant; Infant, Newborn; Male; Methicillin; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Penicillins; Prevalence; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Contraindications; Humans; Liver Transplantation; Methicillin Resistance; Mupirocin; Nose; Risk; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Vancomycin

Weekly culture surveillance was conducted over a 2-year period to determine the incidence of methicillin-resistant Staphylococcus aureus nasal colonization among acquired immunodeficiency syndrome patients cared for in a day-care unit and in an infectious diseases unit. Analysis of genomic DNA profiles showed a predominant pattern in both units.

Topics: Acquired Immunodeficiency Syndrome; Brazil; Carrier State; Hospitals, University; Humans; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Methicillin-resistant Staphylococcus epidermidis (MRSE) is a common cause of deep sternal infections. The aim of the present investigation was to evaluate staff in an operating suite for thoracic and cardiovascular surgery as a possible source of MRSE and the possibility of reducing the amount of MRSE shed into the air by wearing tightly woven scrub suits. A second aim was to compare the results of dispersal obtained in a test chamber with those from an operating room. We studied carriage of MRSE in the nose and on different skin sites and made an experimental study of dispersal of MRSE during exercise in a test chamber and during operations, using two different types of scrub suits. Dispersal of MRSE [defined as > 1% of the total count of colony forming units (CFU) shed into the air] occurred in 25% of women and 43% of men. Nasal carriage was found among 28% in women and 33% in men. Among five skin-sampling sites, carriage of MRSE was most frequent on the cheek (50%) and in the axilla (24%) and least frequent in the perineum (5%). Dispersal of MRSE was however more strongly associated with carriage in the perineum (P = 0.097) than on the cheek (P = 0.5) and in the axilla (P = 0.21). With regard to shedding of bacteria into the air, there was a significant difference in favour of the tightly woven clothes regarding total counts of CFU both in the test chamber (P = 0.02) and the operating theatre (P = 0.002). Regarding MRSE, no such difference was found. We found there were too many dispersers of MRSE among operating department staff to exclude them from work. Although tightly woven scrub suits significantly reduced the amount of bacteria shed into the air, the amount of MRSE was not significantly reduced. Full-scale experiments in operating rooms are not needed when evaluating the protective capacity of different scrub suits as results from a test chamber give conclusive information.

Topics: Air Microbiology; Colony Count, Microbial; Female; Humans; Infectious Disease Transmission, Professional-to-Patient; Male; Methicillin Resistance; Nose; Operating Rooms; Protective Clothing; Skin; Staphylococcal Infections; Staphylococcus epidermidis; Sweden; Thoracic Surgical Procedures

Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection in infants has become a serious concern and a new means of preventing the transmission of MRSA in the community needs to be considered.. We performed nasal mupirocin treatment on 10 infants who were MRSA-positive either in the nose or the pharynx and evaluated the effect of mupirocin on the eradication of MRSA.. Eradication of MRSA from the nose was successful in two cases and eradication from the pharynx in six (66.6%) of nine cases. The number of treatments required to achieve eradication varied; within three courses for nose carriers and from one to seven courses for pharynx carriers. Eradication was unsuccessful even after five to seven treatments in three pharynx-limited carriers.. These data suggest that the effect of nasal mupirocin treatment on pharynx-colonized MRSA is limited and that repetitive treatment is necessary in some cases. However, in view of the possibility of preferential pharyngeal colonization of Staphylococcus aureus in infancy, nasal mupirocin treatment deserves further evaluation for eradication not only of nose- but also of pharynx-colonized MRSA.

Topics: Administration, Intranasal; Carrier State; Cross Infection; Female; Humans; Infant, Newborn; Male; Methicillin Resistance; Mupirocin; Nose; Pharyngeal Diseases; Pharynx; Staphylococcal Infections; Staphylococcus aureus

To assess the risk of infection of either subcutaneously implanted central venous access devices or percutaneous central venous catheters inserted via a subcutaneous tunnel in cancer patients with a positive staphylococcal nasal carriage.. Prospective study.. The study included 266 patients undergoing cancer chemotherapy.. A nasal swab was taken prior to insertion of the venous access device and the patients were followed over 30 days for the occurrence of a staphylococcal infection (hemoculture and device or site of insertion).. A nasal staphylococcal nasal carriage was found in 227 patients. Out of the 15 developing a device infection, a staphylococcal nasal colonization was existing in nine patients. Bacteriological screening a sensitivity of 60% and a specificity of 13%.. Bacteriological screening at the time of device insertion of a central venous access device is of no value for the detection of patients at risk of staphylococcal infection of the device.

Topics: Carrier State; Catheterization, Central Venous; Catheters, Indwelling; Equipment Contamination; Humans; Neoplasms; Nose; Prospective Studies; Risk Factors; Sensitivity and Specificity; Staphylococcal Infections

To determine the relative importance of different risk factors for the development of surgical-site infections (SSIs) in orthopedic surgery with prosthetic implants.. In a cohort of 272 patients, the following possible risk factors were studied: age, gender, method of hair removal, duration of operation, surgeon, underlying illness, and nasal carriage of Staphylococcus aureus. Infections were recorded following the Centers for Disease Control criteria. The relation between risk factors and SSI was tested in univariate and multiple logistic regression analysis.. Community hospital in Breda, The Netherlands.. 18 (6.6%) of 272 patients experienced SSI: 11 superficial and 7 deep SSI. These infections led in three cases to removal of the prosthesis and caused 286 extra days in hospital. The main causative pathogen was S aureus. In multiple logistic regression analysis, the following factors were independent risk factors for the development of SSI: high-level nasal carriage of S aureus (P=.04), male gender (P=.005), and surgeon 1 (P=.006). The only independent risk factor for SSI with S aureus was high-level nasal carriage of S aureus (P=.002).. High-level nasal carriage of S aureus was the most important and only significant independent risk factor for developing SSI with S aureus.

Topics: Analysis of Variance; Cohort Studies; Humans; Length of Stay; Logistic Models; Male; Netherlands; Nose; Orthopedic Procedures; Population Surveillance; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Topics: Anti-Bacterial Agents; Drug Resistance, Multiple; Humans; Methicillin Resistance; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

Due to the emergence of mupirocin-resistance in some epidemic strains of methicillin resistant Staphylococcus aureus (EMRSA) and the appearance of EMRSA with intermediate resistance to vancomycin, we evaluated the in-vitro activity of 5% povidone-iodine ('Betadine') cream as a possiblealternative to mupirocin for the elimination of nasal carriage of S. aureus. As judged by enrichment culture, povidone-iodine was bactericidal against three mupirocin-sensitive strains of S. aureus from nasal carriers, and against mupirocin-resistant and -sensitive strains of EMRSA types 3, 15 and 16, after incubation with povidone-iodine for 1.0 min at 32 degrees C. Mupirocin nasal ointment did not prevent growth after 180 min incubation. In a quantitative suspension test, 1:100 dilution of povidone-iodine cream completely eliminated an inoculum of 10(8)cfu/mL of all nine test organisms after incubation at 32 degrees C for 1.0 min, and 1:1000 dilution reduced cfu, by a factor of 10(5). After direct inoculation of the povidone-iodine cream to give 10(5)cfu/g, none of the test strains were recoverable after 30 s, giving a killing rate of approximately 10(4)cfu/s; for mupirocin nasal ointment, the maximum reduction of mupirocin-sensitive strains was ten fold after 3 h. Povidone-iodine activity was not detectable in sensitivity-testing agar, although 0.025% of povidone-iodine was detectable in a 15% nutrient strength tryptone soya agar. Using this minimal medium, the addition of nasal secretions (from any of 11 samples) reduced the activity of povidone-iodine by 80-90%, but mupirocin activity was unaffected. One millilitre of nasal secretions inactivated the equivalent of approximately 22.5 mg of povidone-iodine. These results suggest that povidone-iodine cream may have a role in the prevention of colonization and infection caused by MRSA, including mupirocin-resistant strains.

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Biological Availability; Carrier State; Drug Resistance, Microbial; Humans; Microbial Sensitivity Tests; Mupirocin; Nasal Mucosa; Nose; Povidone-Iodine; Staphylococcal Infections; Staphylococcus aureus

Contrasting data are reported in the literature on the percent positivity rates (13.5%-100%) of exfoliative toxin (ET) production by S. aureus strains isolated from impetigo patients in Japan and in France. In the present study, by means of a recently available latex-test, toxin-A (ETA) or toxin-B (ETB) production was found in 67.6% of the 34 S. aureus strains isolated from 19 lesional (63.2%) and 15 non-lesional (nose or pharynx, 73.3%) areas of patients with impetigo (with no significant difference between the lesional and non-lesional isolates). ETA + ETB were produced by 44.1% of the strains, while 32.4% were non-producers. In contrast, the percent positivity rate observed in 40 [20 lesional and 20 non-lesional (nose or pharynx)] strains isolated in patients with atopic dermatitis was 15.0% (p < 0.001 both for the lesional and non-lesional strains versus impetigo, with no significant difference between lesional and non lesional strains). Finally, 26 strains from other types of specimens (abscesses, hemocultures, urine, central venous catheters, bronchoalveolar lavages) showed an 11.5% production rate of ETA or ETB (p < 0.001 versus impetigo strains, no significance versus atopic dermatitis). These data point to a significant association between exfoliative toxin production and S. aureus strains isolated in impetigo, both in lesional areas and in nasal/pharyngeal reservoirs. An attempt to correlate SmaI pulsed-field gel electrophoresis (PFGE) restriction patterns and exfoliative toxin production showed no significant association in either group.

Topics: Adolescent; Adult; Aged; Bacterial Typing Techniques; Child; Child, Preschool; Deoxyribonucleases, Type II Site-Specific; Dermatitis, Atopic; Electrophoresis, Gel, Pulsed-Field; Exfoliatins; Female; Humans; Impetigo; Infant; Male; Middle Aged; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

PFGE has been extensively used to obtain a reliable intra-species differentiation, although this technique has not been completely standardized. In this study, PFGE was applied to analyze in detail the patterns of 19 lesional S. aureus strains isolated from patients with impetigo, compared with 15 non-lesional strains isolated from nasal or pharyngeal swabs of the same patients. The strain DNA was extracted and processed as previously reported, using the strictest protocol to limit the variations between different analytical sets. To obtain maximum sensitivity and comparability, the electrophoresis patterns were analyzed by an automated and computerized reader (GelDoc1000). The DNA fragments (range 12-15 bands) obtained for each individual strain were then divided into 39 zones including from 1 to 4 bands for a total of at least 91 possible different gel positions. The positivity for each zone (and/or the positivity for the individual bands contained) was associated with the lesional/non-lesional origin and with the face localization of the strains.

Topics: DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Humans; Impetigo; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

A group of patients (n=86) suffering from superficial abscesses was recruited in the Khartoum Teaching Hospital, Sudan. Detailed clinical and socio-economic data were collected. It appeared that 83% of all patients were younger than 40. Labourers were most prevalent (28%), followed by students (23%) and housewives (16%). The head and neck were most often affected (22%), with hands being second (19%). In 92% of all pus cultures a microbial agents was identified, the large majority being Staphylococcus aureus (69%). Among patients, 47% were nasal carriers of S. aureus, similar to the carriage rate measured among controls, suggesting that nasal carriage is no risk factor for abscess development. Multivariate logistic regression analysis revealed that a history of abscess, recent traditional medical treatment, poor hygiene and low socio-economic status were significantly and independently associated with the occurrence of superficial abscesses.

Topics: Abscess; Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; DNA Fingerprinting; Female; Genotype; Humans; Hygiene; Infant; Male; Medicine, African Traditional; Middle Aged; Nose; Risk Factors; Skin Diseases, Bacterial; Socioeconomic Factors; Staphylococcal Infections; Staphylococcus aureus; Sudan

Staphylococcus aureus is frequently isolated from patients with infections related to continuous ambulatory peritoneal dialysis (CAPD). In many cases, the organism is also isolated simultaneously from the anterior nares. To clarify the transmission trail of S. aureus, we used DNA analysis to identify clonotypes of clinical strains. The nares and exit sites of 32 CAPD patients were swabbed, and PD fluid samples were taken for pathogen culture. Genome DNA of S. aureus was digested with restriction enzyme Sma I for pulsed-field gel electrophoresis. We also asked the patients how they usually performed the PD procedure. S. aureus was isolated from 4 patients, including 3 who hosted two strains isolated separately from different sites. The DNA patterns of the strains isolated from these latter 3 patients were identical. However, the clonotypes from all 4 patients were different. Most of the patients did not wash their hands and wear masks while exchanging PD bags and caring for their exit sites. After the patients were disinfected and re-educated in proper procedures, S. aureus was not detected in any of them. These data suggest that no outbreak occurred in our hospital and that the vectors of endogenous infection were the patients themselves, probably their hands. A bacteriological study presents an efficient opportunity to re-educate patients in PD procedure.

Topics: Adult; Aged; Catheters, Indwelling; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus nasal carriage (SANC) is a risk factor for development of S. aureus dialysis-related infections. Reported here are results of a SANC surveillance and treatment program employed by our dialysis unit over a two-year period. Surveillance nasal cultures were performed at 3-month intervals in 129 peritoneal dialysis patients. Those with SANC applied mupirocin ointment intranasally 3 times daily for 5 consecutive days for 3 consecutive months. Treatment was repeated only when subsequent cultures showed SANC. Infection and catheter loss rates were compared to 63 historical controls, and between SANC and non SANC patients of the study group. Patients who were initially non carriers showed increasing probability for acquiring SANC throughout the study period. Following treatment, the probability for recurrence of SANC was 26%, 41%, 58%, and 62% at 1, 3, 6, and 12 months. The rates of S. aureus exit-site or tunnel infection (p = 0.36), peritonitis (p = 0.0002), and catheter loss (p = 0.01) were lower in the study group as compared to controls. Despite treatment, SANC patients demonstrated a twofold increase in exit-site/tunnel infection rate (p = 0.03) and a threefold increase in catheter loss rate (p = 0.1) as compared to non SANC patients. The high rate of SANC recurrence and the long interval between surveillance cultures may explain the failure of the current protocol to completely eliminate the risk for S. aureus infections. The results support a change in the treatment plan to that of continuing the monthly mupirocin regimen indefinitely once SANC has been identified.

Topics: Anti-Bacterial Agents; Antibiotic Prophylaxis; Carrier State; Catheters, Indwelling; Female; Humans; Male; Middle Aged; Mupirocin; Nose; Peritoneal Dialysis; Peritonitis; Prospective Studies; Recurrence; Staphylococcal Infections; Staphylococcus aureus

Nasal carriage of Staphylococcus aureus is a risk factor for catheter-related infections with S. aureus in patients on chronic peritoneal dialysis (CPD). In children, S. aureus may transmitted to the catheter either from the patients' nares, or from the nares of caregiving carriers. As part of a prospective trial on the efficacy of mupirocin prophylaxis in children on CPD and their caregivers, we evaluated the prevalence of S. aureus carriage in 92 families of pediatric CPD patients. Patients and their caregivers (usually both parents) were screened by three nasal cultures obtained within four weeks. In 62% of the families, neither the patients nor any caregiver carried S. aureus. In 23%, the patient or at least one caregiver (sometimes both) was identified as a carrier. In 15%, at least one caregiver, but not the patient, was colonized with S. aureus. During further follow-up by once-monthly nasal cultures, 5 of the 57 initially negative patients developed S. aureus colonization, and in two families, at least one caregiver turned positive. Including these "occasional" carriers, the cumulative likelihood of one or several family members carrying S. aureus gradually increased to a plateau of about 55% after 6 observation months. Susceptibility rates of cultured S. aureus were 100% for vancomycin, 99% for aminoglycosides, 95% for piperacillin/tazobactam, 94% for cephalosporins, and 15% for ampicillin. In two patients and two caregivers (four different families), methicillin-resistant S. aureus was found. Three isolates from three different families were resistant to mupirocin. We conclude that S. aureus colonization is common in families of children on CPD. While 85% of carrier families are detected by 3 sequential nose cultures in patient and caregivers, up to 9 cultures may be required in "occasional" carriers.

Topics: Adolescent; Caregivers; Carrier State; Child; Child, Preschool; Family Health; Humans; Infant; Microbial Sensitivity Tests; Nose; Peritoneal Dialysis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Abscess; Amoxicillin; Child; Hematoma; Humans; Male; Nasal Septum; Nose; Nose Diseases; Penicillins; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus is a common cause of serious infection in patients infected with HIV.. To evaluate risk factors for and quantitative effect of S. aureus infection in HIV-infected patients, with special attention to nasal carriage.. Prospective, multihospital cohort study.. Three tertiary care Veterans Affairs Medical Centers.. 231 ambulatory HIV-infected patients.. Thirty-four percent of patients were nasal carriers of S. aureus. Of these patients, 38% were persistent carriers and 62% were intermittent carriers. Twenty-one episodes of infection occurred in 13 patients: Ten were bacteremias (including 2 cases of endocarditis), 1 was pneumonia, and 10 were cutaneous or subcutaneous infections. Seventeen (85%) of these episodes occurred in patients with CD4 counts less than 100 cells/mm3. Recurrent infections occurred in 3 of 7 patients who survived an initial S. aureus infection. The mortality rate was higher among patients with S. aureus infection than among those without infection (P = 0.03). Factors significantly associated with S. aureus infection were nasal carriage, presence of a vascular catheter, low CD4 count, and neutropenia. Molecular strain typing indicated that for 6 of 7 infected patients, the strain of S. aureus isolated from the infected sites was the same as that previously cultured from the nares.. Nasal carriage is an important risk factor for S. aureus infection in HIV-infected patients. Controlled studies are indicated to determine whether eradication of nasal carriage in a selected subset of patients (for example, those with a low CD4 cell count) might prevent invasive S. aureus infection in patients with HIV infection.

Topics: Acquired Immunodeficiency Syndrome; AIDS-Related Opportunistic Infections; Analysis of Variance; CD4 Lymphocyte Count; Humans; Neutropenia; Nose; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Child; Fractures, Closed; Humans; Male; Manipulation, Orthopedic; Nose; Postoperative Complications; Shock, Septic; Staphylococcal Infections

The recent evolution in the epidemiology of methicillin-resistant asymptomatic Staphylococcus aureus (MRSA) infections in children, whereby children without traditional risk factors for MRSA have been hospitalized in increasing numbers, prompted us to establish whether a parallel increase in "asymptomatic" MRSA colonization had occurred.. We cultured the nares and perineum of 500 children attending our Pediatric Emergency Department.. One hundred thirty-two (26.4%) of these children were colonized with S. aureus. Eleven (8.3%) of the S. aureus isolates were MRSA; 4 (36.4%) of the 11 subjects colonized with MRSA had no risk factors. Seven (5.3%) of the 132 S. aureus isolates were borderline methicillin-resistant S. aureus (BRSA); 5 (71.4%) of the 7 subjects colonized with BRSA had no MRSA risk factors.. These findings indicate that MRSA and BRSA isolates are circulating in the community and that MRSA isolates are no longer confined to children with frequent contact with a health care environment.

Topics: Adolescent; Carrier State; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Methicillin Resistance; Microbial Sensitivity Tests; Nose; Oxacillin; Penicillins; Perineum; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Rabbits of 19 rabbitries were examined for the presence of Staphylococcus aureus in nine different body sites. Seven rabbitries experienced epidemically spreading signs of staphylococcosis while the other 12 rabbitries did not. S. aureus was isolated in all seven flocks that suffered from chronic problems of staphylococcosis and in 11 of the 12 clinically healthy flocks. The mean percentage of infected animals in these two groups was 90 and 43.3%, respectively. S. aureus was isolated from all body sites examined, but the ear and the perineum were often more intensely colonized. The number of animals colonized with S. aureus and the mean number of positive body sites in S. aureus positive rabbits were significantly higher in rabbitries with chronic staphylococcosis. This indicates that colonization capacity of S. aureus plays a role in epidemically spreading disease in rabbits. S. aureus isolates belonged to five different biotypes and 23 different phage types. Several different types simultaneously circulated in contaminated rabbitries and even simultaneously infected individual rabbits. Strains that belonged to the biotype-phage type combination mixed CV-C, 3A/3C/55/71 only occurred in rabbitries chronically dealing with signs of staphylococcosis. This may indicate a relationship between phenotypic strain properties and virulence of S. aureus.

Topics: Animals; Bacteriophage Typing; Ear; Female; Forelimb; Male; Nipples; Nose; Perineum; Rabbits; Skin; Staphylococcal Infections; Staphylococcus aureus; Vagina

Staphylococcus aureus bacteremia (SAB) acquired in hospitals continues to be a frequent and serious complication to hospitalization, and no previous case-control studies dealing with risk factors of this severe disease are available.. Based on a 1-year prospective analysis, the data from all patients with hospital-acquired SAB admitted to 4 hospitals in Copenhagen County, Denmark, from May 1, 1994, through April 30, 1995, were evaluated. Eighty-five patients with hospital-acquired SAB were matched to 85 control patients with a similar primary diagnosis at admission (matched controls). Of these, 62 patients with hospital-acquired SAB were compared with 118 other patients with a similar time of admission, who were randomly selected with no clinical evidence of SAB (unmatched controls).. The incidence of hospital-acquired SAB was 0.71 per 1000 hospital admissions. The presence of a central venous catheter (odds ratio, 6.9; 95% confidence interval [CI], 2.8-17.0), anemia (odds ratio, 3.3; 95% CI, 1.4-7.6), and hyponatremia (odds ratio, 3.3; 95% CI, 1.5-7.0) was significantly associated with hospital-acquired SAB in a conditional and a usual logistic regression analysis. Nasal carriage was not an independent risk factor, but nasal carriers among patients in surgery (odds ratio, 4.0; 95% CI, 1.3-13.0) had a significantly higher risk for hospital-acquired SAB compared with matched and unmatched controls. The presence of hospital-acquired SAB increased the mortality rate 2.4-fold (95% CI, 1.1-5.2).. The presence of a central venous catheter is an important risk factor, and hyponatremia and anemia are associated with the development of hospital-acquired SAB. Furthermore, hospital-acquired SAB in itself increases mortality.

Topics: Adolescent; Adrenal Cortex Hormones; Adult; Age Factors; Aged; Aged, 80 and over; Anemia; Anti-Bacterial Agents; Bacteremia; Case-Control Studies; Catheterization, Central Venous; Child; Child, Preschool; Cross Infection; Denmark; Female; Hospitals, Community; Humans; Hyponatremia; Immunocompromised Host; Infant; Infusions, Intravenous; Male; Middle Aged; Nose; Odds Ratio; Prospective Studies; Regression Analysis; Renal Dialysis; Risk Factors; Sex Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Procedures, Operative; Survival Analysis; Transfusion Reaction

A 6-month longitudinal study was conducted on 30 dairy cows in early lactation and their human handlers on six farms across Trinidad. Weekly samples of bulk milk, composite milk and anterior nares and hand swabs from human handlers were collected and cultured for Staphylococcus aureus on Baird-Parker agar (BPA). The susceptibility of S. aureus strains to bacteriophages and the relatedness of strains isolated over the study period were determined. Sixty-three (51.2%) of 123 strains of S. aureus from bulk milk were typable compared with 111 (57.3%) of 194 and 82 (61.7%) of 133 strains isolated from composite milk and human handlers, respectively. The differences were not statistically significant (P > 0.05; chi 2). Bovine phage 42D lysed 3.3% (4 of 123), 16.5% (32 of 194) and 12.0% (16 of 133) of S. aureus strains isolated from bulk milk, composite milk and human handlers, respectively. The differences were statistically significant (P < 0.001; chi 2). Amongst bulk milk isolates of S. aureus, 35 (31.8%) of 110 exhibited relatedness in 11 groups based on their phage patterns and groups. The mean maximum interval between the first and last detection of related S. aureus strains in a group was 11.5 +/- 7.3 weeks. Amongst composite milk strains of S. aureus, 23 (46.0%) of 50, 25 (62.5%) of 40 and 22 (53.7%) of 41 exhibited relatedness on farms IB 2, IB 27 and IC 23, respectively, but the differences were not statistically significant (P > 0.05; chi 2). On farm IB 2, five groups of related strains of S. aureus were detected with a mean maximum interval of detection of 18.2 +/- 8.5 weeks compared to farm IB 27 where five groups of related strains were also observed but with an interval of 13.8 +/- 8.2 weeks. On farm IC 23, a total of seven groups of related S. aureus strains were detected with a mean interval of 8.0 +/- 5.5 weeks. For human strains of S. aureus from farm IB 2, nine (56.3%) of 16 strains isolated from anterior nares exhibited relatedness in three groups with a mean maximum interval of 13.3 +/- 4.7 weeks compared to four (25.0%) of 16 hand swab isolates which exhibited relatedness in two groups with mean interval of detection of 11.0 +/- 1.4 weeks. The differences were not statistically significant (P > 0.05; chi 2). On farm IB 27, for anterior nares isolates, eight (72.7%) of 11 exhibited relatedness in two groups with a mean maximum interval of detection of 20.5 +/- 2.1 weeks compared to hand swab isolates, with six (50.0%) of 12 showing relatedn

Topics: Animals; Bacteriophage Typing; Cattle; Cattle Diseases; Female; Hand; Humans; Lactation; Longitudinal Studies; Milk; Nose; Staphylococcal Infections; Staphylococcus aureus; Trinidad and Tobago

The aim of the study was to elucidate the relationship between the cytokine response to staphylococcal enterotoxin A (SEA) at birth and subsequent staphylococcal colonization in the first months of life. In a cohort of 45 newborns, cord blood lymphocytes were stimulated with SEA (10 ng/ml) in vitro, re-stimulated with PMA (phorbol myristate acetate) and ionomycin at day 3 and assessed for CD45RO expression and cytokine generation by flow cytometry. The infants were classified into three groups according to nasal staphylococcal colonization and enterotoxin generation at 3 months: There were 16 infants with either no colonization or non-enterotoxin-producing staphylococci, 16 infants with enterotoxins B, C, D and E, and 13 infants colonized with SEA-producing staphylococci. At birth, the group without subsequent colonization displayed a significantly higher frequency of CD45RO-positive interferon-gamma-producing cells (1.7%; range 0.0-9.3%) in comparison to the SEA-positive group (0.1%; range 0.0-0.4%) and also to the group positive for other enterotoxins (0.50%; range 0.0-2.5%). Comparable but less pronounced results were found for interleukin-5 but not for interleukins 2 and 4. At 6 months, no differences in cytokine generation were detected between the three groups. The results provide evidence that a non-specific immunologic immaturity at birth is a risk factor for early bacterial colonization. Furthermore, it is remarkable that this immaturity is similar to that seen in infants destined to be atopic with respect to disequilibrium of interferon-gamma to interleukin-4 generation. Thus the link between early staphylococcal colonization and subsequent atopy requires further investigation.

Topics: Age Factors; Enterotoxins; Female; Fetal Blood; Humans; In Vitro Techniques; Infant; Infant, Newborn; Interferon-gamma; Interleukin-4; Interleukin-5; Leukocyte Common Antigens; Lymphocyte Activation; Male; Nose; Staphylococcal Infections; Staphylococcus aureus; T-Lymphocyte Subsets

Ecological niches of Staphylococcus aureus are the anterior nares. Carriage of Staphylococcus aureus in the nose appears to play a key role in the epidemiology and pathogenesis of infection. Numerous studier have shown that elimination of nasal carriage using Mupirocin also eliminated hand carriage and the spread of infections in hospitals. Lipovitellin-Salt-Mannitol Agar was used for screening, isolation and presumptive identification of Staphylococcus aureus from nasal carriers. From November; 97 to August'98, 724 nasal swabs were cultured and 18.23% of health care workers were found to be nasal carriers of Staphylococcus aureus. Of these 12.15% were carriers of MRSA. The carrier rate was highest in December' 97 (32.07%). All MRSA carriers were treated with local application of Mupirocin for three days. A study of the antibiogram of the clinical isolates during the corresponding period showed 100% susceptibility of MRSA to Vancomycin. Susceptibility of MRSA to Clindamycin, Netilmycin, Rifampicin & Ofloxacin was 86.6%, 69.5%, 66% & 64.7% respectively.

Topics: Bacteriological Techniques; Cardiac Care Facilities; Carrier State; Culture Media; Egg Proteins; Egg Proteins, Dietary; Health Personnel; Humans; Mannitol; Methicillin Resistance; Nose; Staphylococcal Infections; Staphylococcus aureus

Within a 1-year period, six surgical-site infections (SSI) caused by Staphylococcus schleiferi were observed in the department of cardiac surgery of Ignatius Hospital, Breda, The Netherlands. Since outbreaks caused by this species of coagulase-negative staphylococci have not been described before, an extensive environmental survey and a case control study were performed in combination with molecular typing of the causative microorganism in order to identify potential sources of infection. Variability, as detected by four different genotyping methods (random amplification of polymorphic DNA [RAPD], conventional and PCR-mediated ribotyping, and pulsed-field gel electrophoresis [PFGE] of DNA macro restriction fragments), appeared to be limited both among the clinical isolates and among several control strains obtained from various unrelated sources. Among unrelated strains, RAPD and PCR-mediated ribotyping identified two types only, whereas seven different types were identified in a relatively concordant manner by conventional ribotyping and PFGE. The latter two procedures proved to be the most useful tools for tracking the epidemiology of S. schleiferi. Four of the outbreak-related strains were identical by both methods, and two isolates showed limited differences. In the search for a potential source of S. schleiferi infection, two slightly different PFGE types were encountered on several occasions in the nose of a single surgeon. These strains were, however, clearly different from the outbreak type. In contrast, S. schleiferi cultures remained negative for two persons identified on the basis of case control analysis. It was demonstrated that SSI caused by S. schleiferi had a clinical impact for patients comparable to that of a wound infection caused by Staphylococcus aureus. This report describes the first well-documented outbreak of S. schleiferi infection. A source of the outbreak was not detected.

Topics: Aged; Bacterial Typing Techniques; Case-Control Studies; Disease Outbreaks; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Male; Middle Aged; Molecular Epidemiology; Nose; Polymerase Chain Reaction; Random Amplified Polymorphic DNA Technique; rRNA Operon; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections after middle ear surgery has recently increased at our hospital. Most of these infections were thought to be hospital-acquired when medical personnel in contact with an MRSA-infected patient may have inadvertently transmitted the pathogen to other patients. To prevent further transmission it is essential that such sources of MRSA infection and transmission routes be selected out and eradicated. Therefore, it is necessary to determine whether the strains of MRSA isolated from infected patients are identical to those obtained from medical personnel in order to prove a reciprocal transmission of organisms between medical personnel and patients. Surveillance bacterial cultures from the anterior nares and hands of medical personnel working in the Department of Otolaryngology, Korea University Guro Hospital, were performed at two different time points: 6 December 1994 and 17 June 1996. Ribotyping with Southern blot technique was used to compare 12 MRSA strains from medical carriers with 60 strains identified from the otorrhea of MRSA-infected patients undergoing middle ear surgery. As results, six different MRSA strains were identified (types I, II, III, IV, V and VI) from ribotyping with EcoR1. One distinct subtype, type I strain, was the most frequently identified strain in both medical carriers and patients. Results also showed that 6 MRSA isolates from 10 medical carriers and 20 from 30 patients contained type I ribotype at first culture. Two medical carriers' isolates and 13 isolates from 30 patients shared the same type I strain at the second surveillance culture. In all, 41 out of 72 MRSA strains (56.9%) shared an identical ribotype pattern. Postoperative MRSA infection rates after treatment of medical carriers and the application of rigorous preventive procedures decreased from 11.9 to 5.7% after first culture and 9.0 to 7.7% following second cultures. These findings confirm that MRSA transmission can occur between medical personnel and patients and that effective preventive measures can reduce the postoperative infection rate.

Topics: Blotting, Southern; Cross Infection; Ear, Middle; Follow-Up Studies; Hand; Humans; Incidence; Infection Control; Korea; Methicillin Resistance; Molecular Epidemiology; Nose; Otitis Media; RNA, Bacterial; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Seventy-six patients with oroantral communications after tooth extraction and chronic maxillary sinusitis were treated as follows: bacterial cultures were taken in all of them and maxillary sinuses were irrigated with an antibiotic from the cephalosporin group. Then, in 36 patients, drainage using the Caldwell Luc procedure was performed, including a naso-antral window. In all patients operations were completed by closing oroantral communications with flaps of the mucosa of the alveolar process close to the fistula. Antibiotics according to antibiogram were administered to all patients at least 10 days after surgery. Retrospective comparison between the results obtained in the first group and those in the second group 1, 3 and 6 months after operation was based on objective findings (condition of the oroantral communication, maxillary sinusitis), side effects (pain, numbness of the operated area, headache) and control radiographs (clear maxillary sinus or with mucosal thickening). The study suggests that transnasal drainage is not required in maxillary sinus surgery and in the closure of oroantral communications. Equally good results are achieved by treating with antibiotics and without drainage of the maxillary sinus into the nose.

Topics: Cephalosporins; Chronic Disease; Drainage; Follow-Up Studies; Headache; Humans; Maxillary Sinus; Maxillary Sinusitis; Mouth Mucosa; Nose; Oroantral Fistula; Pain, Postoperative; Radiography; Recurrence; Retrospective Studies; Sensation Disorders; Staphylococcal Infections; Streptococcal Infections; Surgical Flaps; Therapeutic Irrigation; Tooth Extraction

An anonymized point-prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage was conducted amongst a stratified random sample of nursing home residents in Birmingham, UK, during 1994. Microbiological sampling from noses, fingers and the environment was undertaken. Information about potential risk factors for the acquisition of MRSA was gathered. MRSA was isolated from cultures of the nose or fingers of 33 of the 191 residents who took part in the study (17%) but only 1 of the 33 positive residents had a clinical infection. Although just 10 of the 87 environmental samples were MRSA positive, there was some environmental contamination in most homes. Risk factors for MRSA carriage were hospital admission within the last year (relative prevalence 2.09, 95% CI 1.13-3.88; P < 0.05) and surgical procedures within the last year (relative prevalence 4.02, 95% CI 2.18-7.43; P = 0.002). Phage-typing of the strains revealed similarities with those circulating in Birmingham hospitals. These findings suggest that the prevalence of MRSA in nursing homes in Birmingham was high, and that the strains may have originated in hospitals.

Topics: Bacteriophage Typing; Carrier State; Cross Infection; Data Collection; Environmental Microbiology; Female; Fingers; General Surgery; Humans; Male; Methicillin Resistance; Nose; Nursing Homes; Patient Admission; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; United Kingdom

Infectious complications associated with electroconvulsive therapy (ECT) are extremely unusual. When five of nine patients undergoing ECT at one facility on June 20, 1996 developed Staphylococcus aureus bloodstream infection (BSI), an investigation was initiated. A retrospective cohort study, a procedure review, and observational and microbiologic studies were performed. A case was defined as any patient who had ECT at Facility A from June 1, 1995 through June 20, 1996 and developed S. aureus BSI <30 days after ECT. The post-ECT S. aureus BSI rate was significantly greater on the epidemic day than the pre-epidemic period, (i.e., June 1, 1995 through June 19, 1996) (5 of 9 vs 0 of 54 patients, P < 0.001). All patients during the study period received propofol before ECT. Case patients were more likely than noncase patients to have higher maximum temperature after ECT (median 103.9 degrees F vs 100.0 degrees F, P < 0.03) and a greater time from preparation of intravenous medications to infusion (median 2.1 vs 1.1 h, P = 0.01). All case-patient S. aureus isolates were indistinguishable by pulsed field gel electrophoresis. Our investigation suggests that the ECT-associated S. aureus BSIs were associated with infection control breaks, which possibly led to the extrinsic contamination of propofol. Prevention of propofol-associated infectious complications requires aseptic preparation and use immediately before infusion.

Topics: Aged; Aged, 80 and over; Anesthetics, Intravenous; Bacteremia; Cohort Studies; Drug Contamination; Electroconvulsive Therapy; Electrophoresis, Gel, Pulsed-Field; Female; Fever; Hand; Humans; Infection Control; Male; Middle Aged; Nose; Peer Review, Health Care; Propofol; Retrospective Studies; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Topics: Adolescent; Endocarditis, Bacterial; Female; Humans; Nose; Staphylococcal Infections

In vitro collagen binding of 216 Staphylococcus aureus isolates from patients with various diagnoses was studied. Polymerase chain reaction was used to examine these isolates regarding the existence of the corresponding cna gene. Distribution of capsular polysaccharide (CP) types was examined. Fifty-six (57%) of 99 S. aureus isolates from patients with endocarditis or bacteremic bone or joint infection were cna-positive compared with 65 (56%) of 117 isolates from bacteremic patients without signs of bone or joint infection (P = .99). There was a good correlation between in vitro collagen binding and presence of the cna gene. These data suggest that collagen binding is not a prerequisite for the development of endocarditis, osteomyelitis, or septic arthritis. There was no significant difference in the distribution of CP types among various patient groups, although there was a strong association between CP type 8 and the existence of the cna gene.

Topics: Antibodies, Bacterial; Antigens, Bacterial; Bacteremia; Bone Diseases, Infectious; Carrier Proteins; Carrier State; Collagen; Endocarditis, Bacterial; Gene Expression; Genes, Bacterial; Humans; Joint Diseases; Nose; Polymerase Chain Reaction; Polysaccharides, Bacterial; Staphylococcal Infections; Staphylococcus aureus; Wound Infection

The frequency of Staphylococcus aureus (SA) nasal carriage and the impact of antibiotic therapy remain undefined in children receiving long-term peritoneal dialysis (PD). We obtained a nasal culture for SA every 4-12 weeks in 21 children (mean age 7.03 +/- 5.8 years) receiving PD from January 1992 to August 1996 (total of 35.3 patient-years). In each case, SA nasal carriage (NSA+) was treated with intranasal mupirocin for 7 days. NSA+ was detected in 13 patients (61.9%) who received dialysis for 28.9 patient-years. Eight (61.5%) of 13 patients became NSA+ during the initial 3 months of dialysis. Seven (53.8%) of the NSA+ patients had 11 exit-site infections (ESI) and one episode of peritonitis (0.42 total infections/patient-year) due to SA. The 8 patients without SA nasal carriage (NSA-) received dialysis for 6.4 patient-years. None of the NSA-patients had an ESI or peritonitis with SA. Finally, the incidence of non-SA infections in the NSA+ and NSA- groups was not different (0.62 vs 0.31 total infections/patient-year, p > 0.05). In conclusion, there appears to be an association between SA nasal carriage and SA ESI in children on PD. The risk of SA peritonitis in NSA+ patients treated with mupirocin may be minimal. The risk of SA nasal carriage may increase with time on dialysis.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Carrier State; Catheters, Indwelling; Child; Female; Humans; Male; Mupirocin; Nose; Peritoneal Dialysis; Peritonitis; Staphylococcal Infections; Staphylococcus aureus

The susceptibility of S. aureus strains isolated from milk and human handlers in dairy farms in Trinidad to bacteriophages was determined. Of the 110 strains isolated from bulk milk, 73 (66.4%) were typable either at routine test dilution (RTD) or 100-RDT compared to 108 (72.5%) of 149 strains from composite milk sensitive but the difference was not statistically significant (P > or = 0.05; chi 2). Strains of S. aureus from human handlers had significantly (P < or = 0.05; chi 2) lower sensitivity, with only 90 (59.6%) of 151 strains typable. Phages in various groups were predominantly more active on both milk isolates, 54.1% (98 of 181) and human strains, 73.3% (66 of 90). Phage 42D alone lysed 22 (12.2%) but with other phages typed 90 (49.7%) of 181 typable strains from milk compared to a lytic activity of only 1.1% (1 of 90) alone and 35 (38.9%) with other phages for strains isolated from human handlers. The differences were however not statistically significant (P > or = 0.05; chi 2). Relatedness of S. aureus strains isolated from bulk milk, composite milk and human handlers on each farm was demonstrated in 21 (46.7%) of 45 dairy farms using the phage patterns detected. Similarly, the relatedness of S. aureus strains isolated from the anterior nares and hands of each human milker was detected on 10 (35.7%) of 28 dairy farms studied. It was concluded that S. aureus strains from human milkers contaminated both composite and bulk milk on the farms studied while bovine strains of S. aureus were also acquired by humans during milking.

Topics: Animals; Bacteriophage Typing; Cattle; Cattle Diseases; Female; Food Microbiology; Hand; Humans; Milk; Nose; Staphylococcal Infections; Staphylococcus aureus; Trinidad and Tobago

Toxic shock syndrome (TSS) is an uncommon, severe, multisystem illness that may follow any surgical procedure. It usually occurs in the immediate postoperative period and is manifested by the sudden onset of a high fever and a variety of other signs and symptoms. The reported incidence of TSS after nasal surgery is 16 cases per 100,000 patients. We report five unusual cases of delayed TSS that occurred after functional endonasal sinus surgery in which no packing was used. Toxic shock syndrome developed in three children and two adults 5 days to 5 weeks postoperatively. All patients were treated successfully with no sequelae. The pathophysiologic features, clinical manifestations, and treatment of TSS are described in detail.

Topics: Adult; Child; Diagnosis, Differential; Endoscopy; Female; Humans; Incidence; Male; Nose; Paranasal Sinus Diseases; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus

To compare the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, the patterns of MRSA acquisition, and the risk for subsequent MRSA infection between a hospital-based, Department of Veterans Affairs (VA) nursing home care unit (NHCU) and community-based nursing homes.. In this prospective study, 148 residents of three community nursing homes and 55 residents of a VA NHCU had their anterior nares swabbed; repeat cultures were obtained from hospitalized patients and/or individuals colonized with MRSA. Subjects were followed up prospectively for 1 year to note hospitalizations and the development of MRSA infections.. The prevalence of MRSA colonization was significantly higher in the VA NHCU than in the community nursing homes (mean +/- SD 30.3% +/- 11% versus 9.9% +/- 4%). The rate of MRSA nares colonization was similar in the two settings. Acquisition of MRSA took place in both the long-term care facilities and hospitals, with 23.8% of incident cases occurring during a hospitalization. Only 3 of the 27 individuals colonized at baseline developed an MRSA infection. A trend toward an increased rate of infection was seen in colonized individuals residing in the community nursing homes versus those in the VA NHCU (relative risk 4.67; 95% Cl 0.55 to 39.9). Forty-seven percent of the 55 subjects hospitalized were colonized at some point during the study. In contrast to residents of the VA NHCU, MRSA colonization in the community facilities was a marker for high mortality.. Outcomes from colonization may be different in the VA NHCU population and the community nursing home population.

Topics: Aged; Cohort Studies; Community-Acquired Infections; Cross Infection; Female; Follow-Up Studies; Hospitalization; Hospitals, Veterans; Humans; Incidence; Long-Term Care; Male; Methicillin Resistance; Nose; Nursing Homes; Prevalence; Prognosis; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Survival Rate

Nasal carriage of Staphylococcus aureus is common among health care workers, but outbreaks caused by such carriers are relatively uncommon. We previously reported outbreaks of S. aureus skin infections that affected newborn infants and were attributed to an S. aureus nasal carrier who had had an associated upper respiratory tract infection (UR) during the outbreak period.. To investigate the contribution of a nasal methicillin-resistant S. aureus (MRSA) carrier (physician 4) who contracted a URI to an outbreak of MRSA infections that involved 8 of 43 patients in a surgical intensive care unit during a 3-week period.. An epidemiologic study of an outbreak of MRSA infections and a quantitative investigation of airborne dispersal of S. aureus associated with an experimentally induced rhinoviral infection.. A university hospital.. 43 patients in a surgical intensive care unit and 1 physician.. Molecular typing was done, and risk factors for MRSA colonization were analyzed. Agar settle plates and volumeric air cultures were used to evaluate the airborne dispersal of S. aureus by physician 4 before and after a rhinoviral infection and with or without a surgical mask.. A search for nasal carriers of MRSA identified a single physician (physician 4); molecular typing showed that the MRSA strain from physician 4 and those from the patients were identical. Multivariate logistic regression analysis identified exposure to physician 4 and duration of ventilation as independent risk factors for colonization with MRSA (P < or = 0.008). Air cultures showed that physician 4 dispersed little S. aureus in the absence of a URI. After experimental induction of a rhinovirus URI, physician 4's airborne dispersal of S. aureus without a surgical mask increased 40- fold; dispersal was significantly reduced when physician 4 wore a mask (P < or = 0.015).. Physician 4 became a "cloud adult," analogous to the "cloud babies" described by Eichenwald and coworkers who shed S. aureus into the air in association with viral URIs. Airborne dispersal of S. aureus in association with a URI may be an important mechanism of transmission of S. aureus.

Topics: Adult; Air Microbiology; Carrier State; Common Cold; Cross Infection; Drug Resistance, Microbial; Humans; Infant, Newborn; Male; Methicillin; Nose; Rhinovirus; Risk Factors; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus

This study was performed to determine the clinical and economic consequences of alternative strategies of preventing Staphylococcus aureus infection in chronic hemodialysis patients by use of intranasal mupirocin calcium to clear nasal carriage of S aureus. Decision analysis evaluated clinical outcomes and cost-effectiveness of three likely management strategies to address S aureus nasal carriage and prevent subsequent infection in chronic ambulatory hemodialysis patients: (1) screen for S aureus nasal carriage every 3 months and treat those with a positive test result with mupirocin calcium; (2) treat all patients weekly with mupirocin calcium; or (3) no prevention strategy, treat infection only. Rates of nasal carriage of S aureus, S aureus infection rates, proportion of infections attributable to nasal carriage, efficacy of mupirocin, natural history of infection, and patient management strategies were derived from the published literature and supplemented by a panel of experts. Actual payments for medical services were obtained from Medicare parts A and B. Incremental cost-effectiveness was calculated from the perspective of Medicare and subjected to sensitivity analyses. Assuming that 75% of S aureus infections are attributable to nasal carriage in hemodialysis patients, eliminating nasal carriage of S aureus with mupirocin calcium (with or without screening) markedly reduces the number of infections (45% to 55%) and also reduces health care expenditures relative to treating infections when they occur. Annual savings to Medicare are $784,000 to $1,117,000 per 1,000 hemodialysis patients, depending on the prevention strategy. Preventing S aureus infection by eradicating nasal carriage in chronic hemodialysis patients reduces morbidity while simultaneously reducing medical care costs. The decision to eliminate nasal carriage on a regular basis or use a screening test to guide antibiotic therapy is dependent on the tradeoff between improved short-term clinical and cost benefits and the potential for bacterial resistance that may arise from widespread use of mupirocin calcium.

Topics: Administration, Intranasal; Ambulatory Care; Anti-Bacterial Agents; Chemoprevention; Clinical Protocols; Cohort Studies; Cost Savings; Cost-Benefit Analysis; Decision Support Techniques; Decision Trees; Drug Costs; Drug Resistance, Microbial; Follow-Up Studies; Health Expenditures; Humans; Medicare Part A; Medicare Part B; Mupirocin; Nose; Renal Dialysis; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome; United States

To determine the relevance of nasal carriage of Staphylococcus aureus, either methicillin-sensitive (MSSA) or methicillin-resistant (MRSA), as a risk factor for the development of nosocomial S aureus bacteremia during an MRSA outbreak.. In this prospective cohort study, 488 patients admitted to an intensive care unit (ICU) during a 1-year period were screened with nasal swabs within 48 hours of admission and weekly thereafter in order to identify nasal S aureus carriage. Nasal staphylococcal carriers were observed until development of S aureus bacteremia, ICU discharge, or death.. One hundred forty-seven (30.1%) of 488 patients were nasal S aureus carriers; 84 patients (17.2%) harbored methicillin-sensitive S aureus; and 63 patients (12.9%) methicillin-resistant S aureus. Nosocomial S aureus bacteremia was diagnosed in 38 (7.7%) of 488 patients. Rates of bacteremia were 24 (38%) of the MRSA carriers, eight (9.5%) of the MSSA carriers, and six (1.7%) of noncarriers. After adjusting for other predictors of bacteremia by means of a Cox proportional hazard regression model, the relative risk for S aureus bacteremia was 3.9 (95% confidence interval, 1.6-9.8; P = 0.002) for MRSA carriers compared with MSSA carriers.. Among ICU patients, nasal carriers of S aureus are at higher risk for S aureus bacteremia than are noncarriers; in the setting of an MRSA outbreak, colonization by methicillin-resistant strains represents a greater risk than does colonization by MSSA and strongly predicts the occurrence of MRSA bacteremia.

Topics: Adult; Aged; Bacteremia; Carrier State; Cohort Studies; Confidence Intervals; Cross Infection; Female; Humans; Intensive Care Units; Male; Methicillin; Methicillin Resistance; Middle Aged; Nose; Proportional Hazards Models; Prospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

A cluster of six pediatric cases of deep-seated Staphylococcus aureus infection after heart operations prompted us to perform molecular typing of the S. aureus isolates by pulsed-field gel electrophoresis. This revealed the presence of genotypically distinct isolates in four of the six patients. Isolates of two patients were genotypically identical. All patients carried S. aureus in the anterior nares. In each patient, the banding pattern of deoxyribonucleic acid in these isolates was indistinguishable from that in strains isolated from blood or wound cultures. Molecular typing with pulsed-field gel electrophoresis ruled out nosocomial transmission of S. aureus between four patients; at the same time, it provided evidence for an association between nasal colonization and postoperative wound infection. Epidemiologic investigation of potential links between two patients with identical isolates did not provide any evidence for nosocomial transmission of S. aureus between these patients. Because nasal colonization with S. aureus may be a risk factor for surgical wound infection in pediatric patients undergoing heart operations, preoperative decolonization appears to be warranted.

Topics: Anti-Bacterial Agents; Bacteremia; Bacterial Typing Techniques; Child; Child, Preschool; Cross Infection; DNA Probes; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Genotype; Heart Defects, Congenital; Humans; Infant; Male; Nose; Preoperative Care; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Sternum; Surgical Wound Infection

A three-month prospective surveillance study was undertaken in four dialysis centres to establish the prevalence of Staphylococcus aureus carriage in a Danish population of patients on haemodialysis (HD) or on continuous ambulatory peritoneal dialysis (CAPD). General data such as sex, age, diagnosis, number of months in dialysis, hospital and ward were registered on a precoded form. Standardized nose and four skin swabs (axillae, groins, perineum) were performed on the first day of the survey. After one and two months, nose swabs were collected. Infections were registered and cultures were sent for phage-typing together with the S. aureus strains isolated from the swabs; 59.5% of HD patients and 51.2% of CAPD patients carried S. aureus. Permanent carriage was most frequent (P < 0.00009), primarily in the nose (44.0 and 34.9%, respectively in HD and CAPD). Skin carriage alone was rare (2.4 and 4.7%). Approximately one third (36.6 and 40.7%) of infections were caused by S. aureus. Although diabetics were not significantly more frequent carriers (60.5%) than non-diabetics (55.0%), the incidence of infection was much higher (26.3% vs. 10.3%, P = 0.004). In CAPD, peritonitis and tunnel/exit-site infections predominated (81.4%), often caused by S. aureus (34.8%). More than two thirds of the infections in HD patients were related to intravascular catheterization. The most serious infection was septicaemia, in all cases due to S. aureus. S aureus infections occurred significantly more frequently among carriers (P = 0.005), and more than half the patients were infected by the same or possibly the same strain as they carried in the nose or on skin. Different regimens for the elimination of S. aureus carriage in dialysis patients are discussed. A policy for risk assessment of patients should be developed, and the elimination of S. aureus carriage before dialysis should be encouraged. Controlled trials comparing the cost-effectiveness of recommended regimens to eliminate carriage in HD/CAPD patients are needed. Nose swabs are reliable indicators of carriage in dialysis patients.

Topics: Carrier State; Denmark; Female; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Prevalence; Prospective Studies; Renal Dialysis; Skin; Staphylococcal Infections; Staphylococcus aureus

Two patients are presented with Wegener's granulomatosis (WG) and lower respiratory tract infections with Staphyloccus aureus (SA). It is posulated that there is a relationship between the infection and the induction or relapse of the disease. We suggest that bronchoalveolar lavages should be performed in cases of suspected WG to identify SA-infections. The co-existence of WG and SA support the reported beneficial effects of sulfamethoxazole/trimethoprim, but needs further evaluation in patients with and without SA-infection of the airways.

Topics: Anti-Bacterial Agents; Bronchoalveolar Lavage Fluid; Colony Count, Microbial; Female; Granulomatosis with Polyangiitis; Humans; Middle Aged; Nose; Recurrence; Respiratory Tract Infections; Sputum; Staphylococcal Infections; Staphylococcus aureus; Trimethoprim, Sulfamethoxazole Drug Combination

Topics: Carrier State; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Female; Humans; Joint Diseases; Knee Joint; Knee Prosthesis; Middle Aged; Nose; Respiratory Therapy; Rhinitis, Allergic, Perennial; Staphylococcal Infections; Staphylococcus aureus; Steroids

To cure the long-term carriage of methicillin-resistant Staphylococcus aureus (MRSA), eradication treatment was given to 10 patients wearing complete dentures. In addition to multiple body sites, MRSA was cultured from the dentures of six patients. The contaminated dentures were rebased and sterilized with heat in order to prevent recolonization. The patients did not use their dentures during the decolonization therapy. Subsequently, MRSA was eradicated from three of these patients but three others remained MRSA-positive despite at least two courses of combined systemic and topical eradication treatment. These particular patients had persistent stomatitis and their dentures were a poor fit, in poor condition and repeatedly grew MRSA. Eradication treatment was successful in the remaining four patients whose dentures were MRSA-negative. These results confirm that dentures may function as foreign bodies and sustain persistent nasopharyngeal. MRSA colonization. Therefore, we suggest that whenever eradication of MRSA is deemed necessary in cases of nasal, oral or pharyngeal carriage, heat treatment of the dentures should be included. Further comparative studies with larger patient populations are needed to evaluate the contribution of dentures to the long-term carriage of MRSA, as well as to assess the value of denture sterilization during the eradication course.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Biofilms; Carrier State; Denture, Complete; Female; Follow-Up Studies; Humans; Methicillin Resistance; Middle Aged; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus; Sterilization; Stomatitis, Denture

Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

Topics: DNA Fingerprinting; Ecological Systems, Closed; Electrophoresis, Gel, Pulsed-Field; Feces; Female; Humans; Male; Nose; Pharynx; Polymorphism, Restriction Fragment Length; Space Flight; Staphylococcal Infections; Staphylococcus aureus; Urine

Topics: Humans; Male; Middle Aged; Nasal Septum; Nose; Shock, Septic; Silicones; Sleep Apnea Syndromes; Splints; Staphylococcal Infections; Surgical Wound Infection

Topics: Cross Infection; Disease Reservoirs; Fingers; Humans; Methicillin Resistance; Nose; Nursing Homes; Patient Admission; Residence Characteristics; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Surgical Procedures, Operative

Topics: Abscess; Adolescent; Anti-Bacterial Agents; Clindamycin; Hematoma; Humans; Male; Nasal Septum; Nose; Nose Diseases; Staphylococcal Infections

Staphylococcus aureus is the most frequently (42%) isolated micro-organism during bacteraemic episodes in haemodialysis patients. Nasal carriage of S. aureus is of major importance in determining the risk of subsequent infections. Indeed, nasal carriage of S. aureus is highly prevalent in uraemic patients from the onset of maintenance dialysis therapy. The strains isolated simultaneously from the nares and the hands are usually the same. Likewise, infecting S. aureus strains and those isolated from nasal surveillance cultures obtained in the same patient are usually similar. S. aureus infections in haemodialysis patients are thus mostly to be considered as auto-infections. The nares are therefore an elective site for the prevention of S. aureus infections in haemodialysis patients. This has been demonstrated with oral rifampin, and more recently with nasal mupirocin, which is highly effective. Long-term application of nasal mupirocin (e.g. once per week) is cost-effective and is only rarely associated with the emergence of mupirocin-resistance in S. aureus.

Topics: Anti-Bacterial Agents; Humans; Mupirocin; Nose; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

Surveillance of 101 hemodialysis patients for Staphylococcus aureus positive nasal cultures was performed by monthly nasal swabs over a 27-month period. All positive cultures were treated with a prophylactic antibiotic regimen. Forty-seven (46.5%) patients had one or more positive cultures. The surveillance period was longer in the S. aureus nasal carriers (p = 0.004). The frequency of positive cultures correlated with the duration of surveillance (p = 0.029). The incidence of S. aureus bacteremia was greater in patients with two or more positive cultures (p = 0.030). This study suggests that continuous surveillance for S. aureus nasal colonization is essential to properly identify all patients at risk of developing S. aureus bacteremias.

Topics: Anti-Bacterial Agents; Bacteremia; Cohort Studies; Drug Therapy, Combination; Female; Hemodialysis Units, Hospital; Humans; Incidence; Kidney Failure, Chronic; Male; Middle Aged; Nose; Retrospective Studies; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Time Factors

Reported cases of toxic shock syndrome (TSS) following nasal surgery or functional endonasal sinus surgery (FESS) are uncommon. Classic TSS is a serious multisystem disorder resulting from Staphylococcus aureus phage I toxic shock syndrome toxin 1 (TSST-1), and it is characterized by fever, rash, hypotension, mucosal hyperemia, vomiting, diarrhea, and laboratory evidence of multisystem organ dysfunction. TSS cases following nasal surgery have been associated with nasal packing, mucosal barrier violation, prior S aureus phage I colonization, as well as low antitoxin antibody levels. Of the 1700 FESS procedures performed at our institution, 3 cases were complicated by classic TSS, with 2 additional patients having a postsurgical course compromised by a milder degree of TSS. Diagnostic criteria, clinical presentation, management, and etiology are discussed, and the possibility of a continuum from mild-to-classic TSS is addressed.

Topics: Adolescent; Adult; Child; Female; Humans; Male; Maxillary Sinus; Mucocele; Nasal Polyps; Nasal Septum; Nose; Paranasal Sinus Diseases; Postoperative Complications; Shock, Septic; Sinusitis; Sphenoid Sinus; Staphylococcal Infections; Tampons, Surgical

Topics: Autoimmunity; Carrier State; Granulomatosis with Polyangiitis; Humans; Nose; Recurrence; Staphylococcal Infections

To examine possible risk factors for relapse, including chronic nasal carriage of Staphylococcus aureus and serial antineutrophil cytoplasmic antibody (ANCA) determinations in patients with Wegener granulomatosis.. Observational cohort study.. Outpatient clinic at a university-affiliated hospital.. Consecutive patients (n = 71) with biopsy-proven Wegener granulomatosis who were seen during follow-up at the outpatient clinic from January 1988 to July 1991. Fourteen patients were ineligible or dropped out; 57 patients were analyzed.. Serial ANCA determinations and swab cultures of both anterior nares for S. aureus taken at each visit every 4 to 6 weeks. Occurrence of infections and relapses of Wegener granulomatosis were identified according to strict, predefined criteria.. Thirty-six of the 57 patients (63%; 95% CI, 49% to 76%) were found to be chronic nasal carriers of S. aureus (> or = 75% of nasal cultures positive for S. aureus). Proportional-hazards regression analysis identified chronic nasal carriage of S. aureus (adjusted relative risk, 7.16; CI, 1.63 to 31.50), creatinine clearance above 60 mL.min-1 (adjusted relative risk, 2.94; CI, 1.27 to 6.67), and a history of previous relapses of Wegener granulomatosis (adjusted relative risk, 1.33; CI, 0.98 to 1.78) as independent risk factors for relapse. Twenty-two of 33 patients persistently or intermittently positive for ANCA had a relapse as opposed to only 1 of 21 persistently negative patients. Relapses of Wegener granulomatosis were not related to diagnosed infections.. Chronic nasal carriage of S. aureus identifies a subgroup of patients with Wegener granulomatosis who are more prone to relapses of the disease, suggesting a role for S. aureus in its pathophysiology and a possible clue for treatment.

Topics: Adult; Aged; Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Biomarkers; Carrier State; Chronic Disease; Cohort Studies; Female; Granulomatosis with Polyangiitis; Humans; Male; Middle Aged; Nose; Proportional Hazards Models; Recurrence; Risk Factors; Staphylococcal Infections

A serial prospective survey of nasal colonization of hospital personnel by methicillin-resistant coagulase-negative staphylococci (MRCNS) was conducted at a Veterans Affairs medical center on three occasions over a 16-month period. The epidemiological typing systems used to assess relatedness included antimicrobial susceptibility profiles; biotyping; phage typing; plasmid profiles; restriction fragment length polymorphism (RFLP) analysis with ribosomal RNA; and plasmid hybridization with a 1.68-MD plasmid as the DNA probe. Forty-three percent of all personnel and 62% of all nurses were colonized with MRCNS. Nurses on the wards (72%) and in the intensive care unit (73%) were significantly more likely to be colonized with MRCNS than nurses who had less contact with patients or those who worked in the operating room. The molecular epidemiological typing systems indicated some degree of relatedness among the strains. Specifically, riboprobe analysis revealed a Dice coefficient of > 90%. However, each typing system detected dissimilarity among strains. Further studies are needed to determine the role that such human reservoirs of MRCNS serve in horizontal transmission to and subsequent infection of hospitalized patients.

Topics: Bacteriophage Typing; Coagulase; Cross Infection; Hospitals, Veterans; Humans; Methicillin Resistance; Nose; Personnel, Hospital; Plasmids; Polymorphism, Restriction Fragment Length; Prospective Studies; Staphylococcal Infections; Staphylococcus

A single point study was conducted to determine which surface sites best represent the density and composition of the coagulase-negative staphylococcal (CNS) colonizing flora in premature neonates. Five different surface sites of six randomly selected neonates hospitalized in a neonatal intensive care unit (NICU) for a month were examined. The individual strains and their clonal organization within CNS species were identified using restriction endonuclease fingerprinting of whole chromosomal DNA and ribosomal RNA genes. Cultures of the scalp, umbilicus, foot, nose and rectum were collected and quantitatively processed. Ten colonies were typed per surface culture. The most dense CNS colonization was noted on the umbilicus (mean 1.2 x 10(4) c.f.u. cm-2), foot (mean 1.6 x 10(3) c.f.u. cm-2) and nose (mean 1.7 x 10(3) c.f.u. cm-2) of NICU neonates. Scalp and rectum were scarcely colonized. Of all the CNS surface isolates, S. epidermidis accounted for 77.7% (219/282) and S. haemolyticus, S. warneri and S. capitis accounted for 20.6% (58/282), 1.4% (4/282) and 0.4% (1/282), respectively. Colonization of each surface site comprised a maximum of five different strains representing four CNS species. Overall, five clones of S. epidermidis, two of S. haemolyticus, one of S. warneri and one of S. capitis were noted among the 282 isolates. The most predominant were two clones of S. epidermidis and one of S. haemolyticus; they accounted for 94% (265/282). Cultures from the foot and scalp represented the most heterogeneous CNS colonization of the five sites examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Bacteremia; Coagulase; Cross Infection; DNA Fingerprinting; DNA, Bacterial; Drug Resistance, Microbial; Foot; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Mucous Membrane; Nose; Rectum; Scalp; Skin; Staphylococcal Infections; Staphylococcus; Umbilicus

This study was carried out on 100 nasal swabs collected from medical personnel (nurses and doctors) and patients inside hospital environment and also from 50 individuals outside hospital. The swabs were inoculated on different culture media for isolation of /staphylococci which were further identified as S. aureus either by classic bacteriologic methods or by one of rapid screening test of S. aureus. The isolated strains were tested for antibiotic sensitivity to some of B-Lactam antibiotics and to other antibiotics. The results showed that significantly higher percentage of coagulase + ve Staph. were isolated from newborn nursery (90%), operating theatre (71.4%) and hemodialysis unit (60%) than those isolated from intensive care unit, cancer chemotherapy, surgery, chest, internal medicine departments (25%, 26.6%, 31.2%, 33.3%, 50%) respectively. It also showed significant difference in isolation rate between persons at the hospital (patients, doctors and nurses) 44% and controls (normal population) 26%. Most isolates of coagulase + ve Staph. were resistant to penicillin G (93.2%), Streptomycin (77.3%), tetracycline (61.4%) and sensitive to cefamandole (95.4%). All coagulase+ve Staph. isolates were resistant to sulphonamide and methicillin and all sensitive to vancomycin.

Topics: Carrier State; Drug Resistance, Microbial; Egypt; Hospital Units; Humans; Incidence; Inpatients; Microbial Sensitivity Tests; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus

This study compared the sensitivity of nasal culture alone versus multiple-site cultures and single versus duplicate sampling for the detection of methicillin-resistant Staphylococcus aureus (MRSA)-colonized individuals in a nursing-home population. Repeat culture of 68 specimens collected from 35 colonized subjects yielded identical results for 57 specimens, (84%), and 89% of the colonized residents (31 of 35) were identified by the first culture of multiple sites. A single nares culture detected 27 (77%) of 35 (first screen) and 29 (83%) of 35 (second screen) residents colonized with MRSA at any site. The most cost-effective screening would consist of a nasal culture only or combined with a gastrostomy tube site, if applicable. To identify all colonized individuals, however, it would be necessary to culture more than one specimen from multiple sites on each resident.

Topics: Aged; Disease Outbreaks; Humans; Methicillin Resistance; Nasal Mucosa; Nose; Nursing Homes; Reproducibility of Results; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus aureus; Wounds and Injuries

The incidence of S. aureus bacteraemia in a haemodialysis unit was studied over 2 years (167.75 patient-years of follow-up) during which nasal calcium mupirocin was used to eradicate nasal S. aureus carriage; this incidence was compared to that previously observed in the same unit before the use of nasal mupirocin (185.8 patient-years). Nasal mupirocin led to eradication of nasal S. aureus carriage in 96.3% of surveillance cultures and to a fourfold reduction in the incidence of S. aureus bacteraemia per patient-year, from 0.097 before mupirocin to 0.024 with mupirocin use (P = 0.008). Once or thrice weekly maintenance regimens of mupirocin were equally efficacious. The incidence of bacteraemia caused by other micro-organisms was not significantly affected. One single mupirocin-resistant isolate was identified in a nasal surveillance culture. Eradication of S. aureus from the nares did not lead to overgrowth by other micro-organisms. Chemoprophylaxis with nasal mupirocin in haemodialysis patients is cost-effective.

Topics: Administration, Intranasal; Adult; Aged; Bacteremia; Carrier State; Cost-Benefit Analysis; Humans; Middle Aged; Mupirocin; Nose; Ointments; Renal Dialysis; Staphylococcal Infections; Staphylococcus aureus

The value of pernasal swabs and direct adenoid swabs in chronic adenoid and adenotonsillar disease was assessed in 175 patients. Prior to adenoidectomy (53 patients) or adenotonsillectomy (122 patients), pernasal and direct adenoid swabs were taken. Adenoid currettings and tonsil tissue were cultured. Haemophilus influenzae was the bacterium most frequently isolated from adenoid currettings and from the centre (core) of the resected tonsil. There was a close relationship between the bacteriology of the pernasal swab and the adenoid tissue and tonsil core in 72 and 71% of patients, respectively. There was an identical profile of pathogens in 52 and 49%, respectively. We suggest that in children with adenoiditis or adenotonsillitis and hypertrophy of the adenoid, a pernasal swab should be used in preference to a throat swab in selecting appropriate antimicrobial therapy. Penicillin and ampicillin are not appropriate blind therapy in chronic adenoid and adenotonsillar infections because of the prevalence of beta-lactamase-producing aerobes (40%) in adenoid and tonsil core in these conditions.

Topics: Adenoidectomy; Adenoids; Adolescent; Ampicillin; Bacteriological Techniques; beta-Lactamases; Child; Child, Preschool; Chronic Disease; Contraindications; Culture Techniques; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Hypertrophy; Male; Nose; Palatine Tonsil; Penicillins; Pharynx; Pneumococcal Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Tonsillectomy; Tonsillitis

Microbial food contamination is at present less frequent than in the past. Nevertheless, Staphylococcus aureus food poisoning is still among the most frequent ones in Italy. The authors screened nasal swabs of 112 person working in five communal feeding services in Rome province; of these, 53 were found to be positive. This percentage (48.3%) does not differ substantially from those found by other researchers in various Italian cites.

Topics: Carrier State; Food Microbiology; Food Services; Foodborne Diseases; Humans; Nose; Pharynx; Prevalence; Rome; Staphylococcal Infections; Staphylococcus aureus; Urban Population

Topics: Catheterization, Peripheral; Catheters, Indwelling; Humans; Nose; Phlebitis; Staphylococcal Infections; Staphylococcus aureus

Intravenous (IV) therapy-associated phlebitis is common, but its causes are ill defined. Some cases may be related to bacterial colonization of the skin surrounding the IV catheter, especially by Staphylococcus aureus. This prospective study examined the association of phlebitis with anterior nares S aureus carriage, as well as with other potential risk factors.. Selected demographic and clinical data and a nares culture were collected from patients on designated wards by us and from the IV therapy team at the time of initial IV catheter placement. Patients were followed up for signs and symptoms of phlebitis for the duration of the initial catheter's use and for up to two additional IV placements. Potential risk factors were compared for patients who developed phlebitis and those who did not by the Cox multivariate proportional hazards model.. During 10 weeks, 273 men with a total of 416 catheter placements had fully evaluable data. Phlebitis occurred during 13.7% of the catheter placements. Nasal cultures yielded S aureus from 14.3% of the patients, but none of the IV team nurses. Surprisingly, S aureus nasal colonization was related (at borderline statistical significance) to a reduction in phlebitis risk. Location of the patient on a surgical ward, the presence of infection at any site, and a larger-gauge catheter were each significant independent risk factors for phlebitis. The highest risk of phlebitis appeared to have been within 12 to 24 hours of catheter placement.. The primary finding of this study was that nasal colonization with S aureus did not increase the risk of developing IV catheter-associated phlebitis. Our rate of IV catheter-associated phlebitis was similar to that in other studies, but the factors predisposing to phlebitis differed somewhat from those in previous studies.

Topics: Catheterization, Peripheral; Catheters, Indwelling; Causality; Humans; Male; Middle Aged; Multivariate Analysis; Nose; Phlebitis; Prospective Studies; Regression Analysis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus; Time Factors

The nasal carriage rate of Staphylococcus aureus among maternal-infant pairs was 18% compared with 39% among hospital staff in Ile-Ife, Nigeria during a 12-week survey. Of the newborns, 46% tested positive compared with 26% of their mothers. The S. aureus phage types recovered were predominantly of the group III type (38%); however, 28% of the strains isolated were non-typable. All the S. aureus strains were resistant to penicillin, 84% to tetracycline, and 35 and 24% were resistant to streptomycin and chloramphenicol, respectively. Altogether 19% of the strains tested were resistant to methicillin.

Topics: Adolescent; Adult; Bacteriophage Typing; Carrier State; Drug Resistance, Microbial; Female; Hospital Units; Humans; Infant, Newborn; Mothers; Nigeria; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus

The value of pernasal retropharyngeal swabs in chronic adenoid and tonsillar disease was assessed in a prospective study involving 52 patients. Prior to adenoidectomy (34 patients) or adenotonsillectomy (17 patients), pernasal and tonsillar swabs were taken and the culture compared to the bacteriology profile obtained in the adenoid and tonsil tissue following surgery. The pernasal swab correctly identified 76% of pathogens isolated in the adenoid tissue. In addition, pernasal swabs forecast the presence of pathogens in 64% of core tonsil specimens, compared to an accuracy of 38% when superficial tonsil swabs were compared to the microbes in the deep tonsil. H. influenzae was the predominant organism isolated in all cultures. Our results clearly demonstrate that pernasal swabs give a representative picture of the adenoid bacterial content. Pernasal swabs are also superior to superficial tonsil swabs in indicating the deep tonsillar organisms.

Topics: Adenoidectomy; Adenoids; Bacteria; Bacterial Infections; Bacteriological Techniques; Child; Child, Preschool; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Lymphatic Diseases; Male; Nose; Palatine Tonsil; Prospective Studies; Staphylococcal Infections; Tonsillectomy

To determine the natural history of colonization by methicillin-resistant Staphylococcus aureus (MRSA) among patients in a long-term care facility. We specifically sought to determine if MRSA colonization was predictive of subsequent infection.. Cohort study.. Long-term Veterans Affairs Medical Center.. A total of 197 patients residing on two units were followed with regular surveillance cultures of the anterior nares.. The development of staphylococcal infection.. Thirty-two patients were persistent carriers of MRSA and 44 were persistent carriers of methicillin-susceptible strains (MSSA). Twenty-five percent of MRSA carriers had an episode of staphylococcal infection compared with 4% of MSSA carriers and 4.5% of non-carriers (P less than 0.01; relative risk 3.8; 95% CI, 2.0 to 6.4). The rate of development of infection among MRSA carriers was 15% for every 100 days of carriage. Using logistic regression analysis, persistent MRSA carriage was the most significant predictor of infection (P less than 0.001; odds ratio, 3.7). Seventy-three percent of all MRSA infections occurred among MRSA carriers. Isolates of MRSA from 7 patients were typed. Colonizing and infecting strains had the same phage type in all 7 patients and the same pattern of plasmid EcoRI restriction endonuclease fragments in 5 patients.. Colonization of the anterior nares by MRSA predicts the development of staphylococcal infection in long-term care patients; most infections arise from endogenously carried strains. Colonization by MRSA indicates a significantly greater risk for infection than does colonization by MSSA. The results offer a theoretic rationale for reduction in MRSA infections by interventions aimed at eliminating the carrier state.

Topics: Aged; Aged, 80 and over; Bacteriophage Typing; Carrier State; Cross Infection; Humans; Methicillin Resistance; Middle Aged; Nose; Nursing Homes; Plasmids; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus

Of 166 strains of Staphylococcus aureus isolated from hospital patients and staff in Ile-Ife, Nigeria, 32% were non-typable (NT). The strains were isolated from skin lesions, eye infections, wounds and nasal flora. Isolates from skin lesions or eye and wound infections were more likely to produce protease (95% and 78% respectively) than nasal isolates (11%). Nearly all (99%) of the strains isolated were resistant to penicillin and 78% were resistant to tetracycline. Streptomycin resistance occurred in 25% of isolates; 19% were resistant to chloramphenicol and 9% to methicillin.

Topics: Anti-Bacterial Agents; Bacteriophage Typing; Carrier State; Conjunctivitis, Bacterial; Deoxyribonucleases; Drug Resistance, Microbial; Humans; Metalloendopeptidases; Nigeria; Nose; Ribonucleases; Staphylococcal Infections; Staphylococcal Skin Infections; Staphylococcus aureus; Wound Infection

Toxic shock syndrome has been associated with rhinologic surgery and medical devices, and it has been linked to a circulating exotoxin of a toxogenic strain of Staphylococcus aureus. One hundred forty patients with rhinosinusitis were studied. Nasal cultures were obtained. The microbiological characteristics are described. The carrier rate for Staphylococcus aureus was 35%. Thirty percent of patients selected for surgery were Staphylococcus aureus carriers. Toxin-capable isolates were identified in 40% of those tested. Users of cocaine, topical decongestants, and steroid sprays had a statistically higher rate of Staphylococcus aureus carriage compared to nonusers. It is hoped that by identifying the population at risk and defining the factors associated with the development of toxic shock syndrome, a cogent policy of prevention can be established.

Topics: Adolescent; Adult; Aged; Bacterial Toxins; Carrier State; Child; Child, Preschool; Female; Humans; Male; Middle Aged; Nose; Prospective Studies; Rhinitis; Risk Factors; Shock, Septic; Sinusitis; Staphylococcal Infections; Staphylococcus aureus

Cultures of nasal or presternal swabs form part of the routine preoperative screening of patients on the cardiac surgical ward. During a trial of antibiotic prophylaxis in 314 patients, preoperative isolates of Staphylococcus aureus and coagulase-negative staphylococci were compared with strains associated with postoperative sternal wound breakdown (24 patients) and prosthetic valve endocarditis (3 patients). Morphology, antibiotic sensitivity pattern, plasmid analysis and phage typing were used to differentiate strains. In only three cases of wound infection and one of prosthetic valve endocarditis were pathogenic staphylococci not distinguishable from preoperative isolates. The collection of superficial swabs for this purpose before cardiac surgery is therefore unlikely to be cost effective.

Topics: Cardiac Surgical Procedures; Endocarditis, Bacterial; Humans; Nose; Postoperative Complications; Premedication; Preoperative Care; Skin; Staphylococcal Infections; Staphylococcus; Sternum; Surgical Wound Infection

An outbreak of nosocomial staphylococcal infections occurred over a six months period in an intensive care unit. This outbreak was caused by a single phage type of oxacillin resistant Staphylococcus aureus (SA) which infected ten patients. Six patients had bacteremia with infected catheter, two with urinary tract infection and two patients had a pneumonia. The median SAPS was 13. Four patients died. An epidemiologic study was performed to know SA nasal carriage prevalence of patients and hospital staff. There were seven isolates of SA from 83 hospital staff and three from 20 patients, all with the same phage type 77. Hospital staff and patients colonisation with a same SA strain is a potential reservoir for epidemic nosocomial infections. Prophylactic measures are hygienic measures like handwashing, but perhaps also patients and staff selective decontamination with topical antimicrobial substances.

Topics: Cross Infection; Disease Outbreaks; Disease Reservoirs; France; Hand Disinfection; Humans; Intensive Care Units; Nose; Nursing Staff, Hospital; Staphylococcal Infections; Staphylococcus aureus

Recent reports have emphasized an increase in both infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) in institutionalized older patients. We studied whether or not local treatment with mupirocin ointment could eliminate nasal colonization with S aureus. A total of 102 patients in a Veterans Administration nursing home were screened for S aureus nasal colonization. Thirty-nine patients (38.2%) were colonized, 18 with methicillin-sensitive Saureus (MSSA) and 21 with MRSA. Almost half of all colonized patients were in the most dependent functional category and there was a significant association of MRSA colonization, but not MSSA colonization, with poor functional status. Colonized patients were treated with mupirocin ointment applied to the anterior nares twice daily for seven days. After treatment, MSSA persisted in only two patients and MRSA in only one patient; thus, nasal colonization was eliminated in 91.4% of colonized patients. At one month and two months follow-up, 11 patients became transiently recolonized and three became persistently recolonized with S aureus. Mupirocin was well tolerated with no side effects noted. Mupirocin ointment may be useful in controlling nasal colonization with S aureus in the nursing home setting.

Topics: Activities of Daily Living; Administration, Topical; Aged; Anti-Bacterial Agents; Carrier State; Drug Resistance, Microbial; Fatty Acids; Homes for the Aged; Humans; Mupirocin; Nose; Nursing Homes; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

Topics: Administration, Topical; Anti-Bacterial Agents; Fatty Acids; Humans; Mupirocin; Nose; Ointments; Staphylococcal Infections

We studied 140 consecutive patients beginning continuous ambulatory peritoneal dialysis (CAPD) at one of seven hospitals to assess the relation of the nasal carriage of Staphylococcus aureus to subsequent catheter-exit-site infection or peritonitis. Shortly before the implantation of the catheters, the patients' anterior nares were cultured for the presence of S. aureus. Antibiotics were not prescribed for the S. aureus carriers, but all the patients were monitored for signs of catheter infection (median follow-up, 10.4 months). At the initiation of CAPD, 63 patients (45 percent) carried S. aureus in the nares. Nasal carriage was more frequent among the 30 patients with diabetes (77 percent) than among the 110 without the disease (36 percent). The carriers of S. aureus had a significantly higher rate of exit-site infection than the noncarriers (0.40 vs. 0.10 episode per year; P = 0.012). Of these episodes, 24 of 34 were caused by S. aureus. The rates of peritonitis of all bacterial types did not differ significantly between the groups, but all 11 episodes of peritonitis caused by S. aureus occurred among the carriers. In 85 percent of the patients with clinical S. aureus infections, the strain from the nares and the strain causing the infection were similar in phage type and antibiotic profile. We conclude that in patients beginning ambulatory peritoneal dialysis, the nasal carriage of S. aureus is associated with an increased risk of catheter-exit-site infection and that the performance of nasal cultures before the implantation of the catheter can identify patients at high risk of subsequent morbidity.

Topics: Adult; Bacteriophage Typing; Carrier State; Catheterization; Female; Humans; Male; Middle Aged; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Risk Factors; Staphylococcal Infections; Staphylococcus aureus

From the period of October 1987 to January 1988, 9 samples were taken from 16 workers in company canteens situated in the Sienna area. The study of enterotoxin staphylococci strains was carried out of the pharynx, nose, skin of the face and the hands. The investigation required the use of the Staphylo-Zyme P.B.I. kit and RPLA Oxoid set. The most frequently found enterotoxins were A and D, either alone or together.

Topics: Carrier State; Face; Hand; Humans; Italy; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus

Methicillin resistant Staph Aureus (MRSA) were studied in a 300 bedded Central Government Hospital Rawalpindi, in which 291 staff members were screened by nasal swabbing. Of 125 cases carrying staph aureus 5 (1.78%) were methicillin resistant. They were treated with Bacitracin ointment to be applied to interior nares four times a day for one week. Hexachlorophane baths daily, chlorhexidine shampoo once daily for a week, and were taken off duty from wards for one day.

Topics: Carrier State; Cross Infection; Humans; Methicillin; Nose; Pakistan; Penicillin Resistance; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus

2% mupirocin ointment applied intra-nasally for 5 days was assessed for elimination of nasal carriage of Staphylococcus aureus in 31 staff members in a children's hospital. Three volunteers failed to complete the trial because of side effects, i.e. buccal reddening and swelling, and unpleasant taste. During treatment staphylococcal nasal carriage was not found in any case; of the 24 post-treatment nasal swabs taken 4 days after treatment 22 were still negative. Re-colonization with S. aureus of different phage types occurred in the remaining two cases.

Topics: Administration, Intranasal; Anti-Bacterial Agents; Carrier State; Child; Cross Infection; Fatty Acids; Female; Hospitalization; Humans; Male; Mupirocin; Nose; Staphylococcal Infections; Staphylococcus aureus

Coagulase-negative staphylococci (CNS) were cultured from the anterior nares of surgeons, theatre and ward staff, and from patients before and 2 weeks after a total hip replacement. The CNS found in ward staff were more resistant to antibiotics than those in surgeons and theatre staff. Methicillin resistance of CNS in patients increased from 4 to 31% following surgery. Gentamicin-resistant CNS were only found postoperatively, in 20% of patients, in most of whom gentamicin-loaded acrylic bone cement was used.

Topics: Anti-Bacterial Agents; Coagulase; Cross Infection; Drug Resistance, Microbial; Humans; Joint Prosthesis; Nose; Orthopedics; Personnel, Hospital; Postoperative Complications; Staphylococcal Infections; Staphylococcus; Surgery Department, Hospital

Topics: Carrier State; Drug Resistance, Microbial; Fusidic Acid; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Coagulase-negative staphylococci, part of the normal skin flora, frequently colonize bioprosthetic devices and are the most common cause of peritonitis in patients undergoing peritoneal dialysis. Using the API STAPH-IDENT system (Analytab Products, Plainview, New York) and plasmid pattern analysis, we investigated the importance of chronic carriage of coagulase-negative staphylococci in the development of peritonitis due to these organisms. During a nine-month period, 182 surveillance cultures of pericatheter skin and anterior nares from 30 patients yielded 102 strains of coagulase-negative staphylococci. Twelve of these patients had 20 episodes of peritonitis due to these organisms. Staphylococcus epidermidis accounted for 75% of surveillance and 79% of peritonitis-associated strains. By plasmid pattern analysis of 47 surveillance and 16 peritonitis-associated strains, only three patients carried identical coagulase-negative staphylococci on two or more occasions, and only three patients developed peritonitis due to organisms cultured previously from body surface sites.

Topics: Coagulase; Humans; Nose; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Skin; Staphylococcal Infections; Staphylococcus; Staphylococcus epidermidis

Topics: Carrier State; Drug Resistance, Microbial; Humans; Nose; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus; Students, Medical

Nine cases of severe hypotension or death compatible with toxic shock syndrome (TSS) as a complication of influenza and influenzalike illness were identified in Minnesota with onsets between Jan 2, 1986, and Feb 23, 1986, in which five of the patients died. During this time, an influenza outbreak was occurring in the state. Cultures of respiratory secretions were performed in eight patients; Staphylococcus aureus was isolated from all of them. Seven S aureus isolates were available for determination of exotoxin production; five isolates produced toxic shock syndrome toxin-1, one produced enterotoxin B, and one produced both. Acute influenza B infection was confirmed in three of four patients for whom throat cultures or acute and convalescent serum samples were available. Two patients fulfilled the Centers for Disease Control-confirmed case definition for TSS. Four additional patients fulfilled the CDC criteria for a probable case of TSS, and TSS was a likely diagnosis in the remaining three patients. The initial presentation was suggestive of nonsuppurative tracheitis or viral pneumonia in eight patients. In the remaining patient, the initial clinical presentation was compatible with staphylococcal pneumonia. This report demonstrates that TSS can occur as a complication of influenza and influenzalike illness.

Topics: Adolescent; Adult; Carrier State; Child; Child, Preschool; Disease Outbreaks; Female; Humans; Influenza, Human; Male; Minnesota; Nose; Pharynx; Prospective Studies; Retrospective Studies; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus

This paper reports the results of a prospective study of antibiotic prophylaxis in 543 patients undergoing open-heart surgery. All patients were given per-operatively either methicillin, 1 g four times a day, or cephalothin, 1 g four times a day. There was no significant difference in the frequency of postoperative infections between the two groups. It was established that per-operative antibiotic prophylaxis selected resistant coagulase-negative staphylococci (CNS) in the nasal flora of cardiac surgery patients, that this change occurred to the same degree whether methicillin or cephalothin was used, that cephalothin favoured colonization with antibiotic resistant species other than CNS. It was found that the staff of the intensive care unit formed a reservoir of multi-resistant CNS.

Topics: Anti-Bacterial Agents; Cardiac Surgical Procedures; Cephalothin; Enterobacteriaceae; Enterococcus faecalis; Female; Humans; Intensive Care Units; Male; Methicillin; Nose; Personnel, Hospital; Premedication; Prospective Studies; Sepsis; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection

The prevalence of nasal colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA) among patients and staff was studied in a section of a Paediatric Surgical Unit in Lisbon between February and July 1985. Nasal colonization was demonstrated in 41% of burned patients, 5% of non-burned patients and 35% of the nurses. Infection by MRSA occurred in 30% of the burns. The isolates had identical serological patterns, slight differences on phage typing and were resistant to methicillin, cephalosporins, tetracycline, erythromycin and aminoglycosides. A chloramphenicol resistance plasmid of 3 Md was present in those isolates which were chloramphenicol resistant and a small plasmid of 1.7 Md which coded for constitutive erythromycin resistance was present in many isolates. Gentamicin, tetracycline and inducible erythromycin resistance were chromosomal. Several reasons for the apparent low virulence of the isolates are discussed. Attempts to control the outbreak by the discharge of colonized or infected patients, improvement of nursing practices and treatment with temporary removal from work of the colonized nurses did not eliminate the organism from the unit.

Topics: Burns; Cross Infection; Humans; Methicillin; Nose; Penicillin Resistance; Plasmids; Portugal; Staphylococcal Infections; Staphylococcus aureus

The acquisition of hospital strains of Staphylococcus aureus by new house officers was studied in an 800-bed referral hospital over a 1-year period. S. aureus isolates, including three strains with characteristic phage patterns that had previously been documented to cause disease in patients and colonize hospital personnel, were recovered from the anterior nares of 35 of 54 newly arrived house officers. There was a significant correlation (r = 0.7475; P less than 0.02) between colonization with the dominant hospital strain (S) and exposure to the hospital environment over 12 months. No hospital-wide increase in infections owing to the S strain was seen during this period, which suggests that house staff acquired this strain from reservoirs within the hospital. The finding of colonization with virulent endemic S. aureus strains in house officers working on every ward of the hospital suggests that new strategies for control of S. aureus nosocomial infections must be considered and evaluated.

Topics: Bacteriophage Typing; Cross Infection; Humans; Internship and Residency; Nose; Staphylococcal Infections; Staphylococcus aureus; Virulence

The carriage of Staphylococcus aureus was studied in a group of 28 men living in a totally isolated environment for a year. Initially, nasal, axillary and perineal swabs were taken at weekly intervals, but from week 24 throat swabs were taken from known nasal carriers. Several attempts were made during the study to eradicate S. aureus. Eight subjects consistently carried their own phage type throughout the study, despite the application of antibacterial agents. In three subjects strains were isolated late in the study of a phage type which had either not been isolated before in this study, or had not been found for a prolonged period. Nine of the 12 nasal carriers also yielded S. aureus from the throat. It is apparent that following attempted eradication, S. aureus may seem to disappear, only to reappear some time later; 'eradication' in this case would be an erroneous appellation.

Topics: Antarctic Regions; Anti-Bacterial Agents; Bacteriophage Typing; Carrier State; Humans; Male; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus

Toxic shock syndrome (TSS) occurs most often in menstruating women who use tampons. It also occurs following surgical procedures. The occurrence of three cases after nasal surgery prompted us to determine the incidence of this complication and to evaluate possible risk factors. Our cases showed that onset of TSS after surgery is rapid. Early symptoms include nausea, vomiting, diarrhea, erythroderma, and hypotension. The wound does not appear grossly infected. Incidence of TSS after nasal surgery during 1980 through 1983 was 16.5 per 100,000, higher than the incidence in women of menstrual age. Splints were used more frequently in patients who developed TSS than in patients who did not. Nasal packing was used in all patients with TSS and in 98% of all patients. Topical or systemic antibiotics did not have a demonstrable protective effect.

Topics: Adult; Female; Humans; Male; Nasal Septum; Nose; Occlusive Dressings; Postoperative Complications; Rhinoplasty; Shock, Septic; Splints; Staphylococcal Infections; Surveys and Questionnaires; Turbinates; Utah

The first description in Portugal of the spread of a methicillin-gentamicin resistant Staphylococcus aureus (MGRSA) epidemic strain in a hospital unit is reported. Ten in-patients, out of a selected group of 200, were colonized by the epidemic strain. The strain was also isolated from one burn and from the nose of three nurses. Possible reasons for the apparent reduced communicability and low virulence of the multi-resistant strain are presented.

Topics: Cross Infection; Gentamicins; Humans; Methicillin; Nose; Penicillin Resistance; Portugal; Staphylococcal Infections; Staphylococcus aureus

In 1,494 pregnant women (on weeks 32-36) staphylococcal carriership was studied. One-third of the women under investigation were found to be carriers, their bacterial discharge increasing in spring and summer. The isolated strains proved to be polyresistant to antibiotics and belonged to epidemic strains. About a half of Staphylococcus aureus strains could not be identified with the use of the international set of phages.

Topics: Bacteriophage Typing; Carrier State; Female; Humans; Nose; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Trimester, Third; Russia; Seasons; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis; Urban Population

The nasal carrier-rate of Staphylococcus aureus in 548 Nigerians aged 9-32 years and attending various educational establishments was 56.4%. This rate decreased with increasing age. A significantly greater proportion of females (65.0%) than males (46.5%) were carriers, but the excess in females was apparent only in subjects aged greater than 20 years. Mucoid strains of S. aureus, which gave a negative slide-coagulase reaction, were found in 21.5% of carriers aged 10-15 years, but were absent from members of other age-groups. A considerable proportion of all the strains tested were resistant to commonly used antibiotics.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Carrier State; Child; Family Characteristics; Female; Humans; Male; Nigeria; Nose; Penicillin G; Penicillin Resistance; Staphylococcal Infections; Staphylococcus aureus

Topics: Adult; Carrier State; Cocaine; Humans; Male; Nose; Sepsis; Staphylococcal Infections; Substance-Related Disorders

Topics: Anti-Bacterial Agents; Bacteriophage Typing; Carrier State; Female; Hospital Departments; Humans; Male; Microbial Sensitivity Tests; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Surgery Department, Hospital

A gentamicin-resistant isolate of Staphylococcus aureus producing staphylococcal enterotoxin F (SEF) was isolated from a burn unit nurse during three episodes of toxic-shock syndrome (TSS). The nurse's reciprocal titer of antibodies to SEF was less than or equal to 5 during the three episodes, and when the titer rose to 1,000 no further relapses occurred despite continued colonization. The unusual antibiotic susceptibility pattern of the organism enabled demonstration of its spread. During four months, 12 (41%) of 29 burn unit patients, three other burn unit nurses, and a household contact of the nurse with TSS became colonized. None, including two patients whose initial reciprocal titers were less than or equal to 5, developed TSS. This experience illustrates significant cross-transmission of a TSS-associated strain and a temporal association of antibodies to SEF with cessation of recurrences of TSS. Additional factors must explain why other individuals lacking antibodies to SEF did not develop TSS.

Topics: Adult; Antibodies, Bacterial; Bacterial Toxins; Burn Units; Burns; Drug Resistance, Microbial; Enterotoxins; Female; Gentamicins; Humans; Male; Nose; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus; Superantigens

The immune status of 60 S. aureus carriers and 60 donors without carrier state was studied with respect to the interrelations of their antistaphylococcal immunity characteristics and natural resistance factors with the levels of different parameters. In contrast to the donors without carrier state, new interrelations between specific and nonspecific humoral immunity factors were shown to appear in S. aureus carriers, their blood sera having the elevated levels of bactericidal activity and the increased titers of staphylococcal antibodies. The phagocytic activity of the blood in the carriers proved to be below the normal level. The S. aureus carriers were found to have disturbances in the interrelations of their phagocytic activity and specific humoral immunity. The immune status of the carriers as characterized by the interrelations of its parameters is compared with the immune status of normal persons.

Topics: Adolescent; Adult; Antibodies, Bacterial; Antibody Formation; Blood Bactericidal Activity; Carrier State; Humans; Immunity, Cellular; Immunity, Innate; Muramidase; Nose; Pharynx; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Carrier State; Fatty Acids; Gentamicins; Humans; Methicillin; Mupirocin; Nose; Penicillin Resistance; Staphylococcal Infections; Staphylococcus aureus

During a 6-month period at Walter Reed Army Hospital the monthly attack rate of Staphylococcus aureus bacteremia increased to 3.8 +/- 0.5 (mean +/- SEM) from 2.5 +/- 0.2 cases per 1,000 dispositions for the previous 48 months (P less than 0.05). A predominant phage pattern, designated S, was found in 12 (39%) of 31 bacteremic isolates typed and another strain, delta, was associated with four catheter-related infections. Two other strains also accounted for infections. Patients with isolates of the S phage pattern had a higher mortality (59%) than patients with non-S isolates (37%). Thirty-eight per cent of S. aureus carriers among hospital personnel harbored S or delta strains. Limitation of intravascular devices, strict handwashing, and the use of gloves were associated with a significant decrease in the incidence of S. aureus bacteremia to 1.9 +/- 0.5/1,000 dispositions over the next 6 months (P less than 0.05). S and delta strains were reduced to 20% of these isolates despite their persistence in 32% of staphylococcal carriers upon reculture of personnel. We conclude that S. aureus persists as an important pathogen in the hospitals, and that phage typing S. aureus isolates remains an important tool in hospital epidemiology. The presence of multiple S. aureus strains causing this outbreak and the extent of their dissemination among patients and personnel reported here emphasizes the need to reevaluate strategies of nosocomial staphylococcal control.

Topics: Clothing; Cross Infection; Epidemiologic Methods; Female; Hand Disinfection; Humans; Male; Middle Aged; Nose; Personnel, Hospital; Sepsis; Staphylococcal Infections; Staphylococcus Phages; Statistics as Topic

Of 200 patients, 6.5% were skin carriers of Staphylococcus aureus and 3.5% became skin carriers after admission. Development of skin carrier state was associated with a long preoperative hospital stay. A second study of 275 cases showed that skin carriers of S. aureus had a significantly higher subsequent staph wound infection rate than non-carriers, but nose and/or throat carriers of S. aureus did not. Peroperative wound contamination was a significant factor in the subsequent development of wound infection. In clean surgery the infection rate was 5.9%. Both wound contamination and infection was due to gram positive organisms, usually S. aureus. When the gastrointestinal or biliary tract had been opened, the infection rate was 28%, the usual contaminating and infecting organisms were enteric and only occasionally S. aureus. There is a need for improved methods of minimizing peroperative wound contamination.

Topics: Bacteriological Techniques; Carrier State; Cross Infection; Humans; Middle Aged; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Augmentation rhinoplasty has become a popular plastic operation in Asia. In Korea most surgeons prefer using silicone rubber prosthesis instead of autogenous material. The authors have used the standard shaped silicone prosthesis, boat-shaped and also L-shaped prostheses. The standard shape prosthesis has less extrusion and fixation problems. In over 1,500 cases, there were 357 complications (20.8%). All the complications were due to the silicone prosthesis acting as a foreign body or failure in design of implant or unskillful operative technique. In order to minimise complications, care should be taken to use the proper size of prosthesis, the correct shape of implant and to ensure that there is adequate undermining and meticulous closure technique. To minimise the overlying skin tension at the tip and on the dorsum of the nose, the cutting of the depressor septi nasi muscle and transverse part of the nasalis muscle are recommended. In this review, we report the types and incidence of complications by analysing the cases seen during the past 10 years in our Unit and offer a few solutions to overcome these complications.

Topics: Asian People; Cerebrospinal Fluid Rhinorrhea; Enterobacteriaceae Infections; Epistaxis; Erythema; Humans; Korea; Nose; Postoperative Complications; Prostheses and Implants; Rhinoplasty; Serratia marcescens; Silicone Elastomers; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Time Factors

Topics: Adult; Carrier State; Humans; Nose; Pharynx; Staphylococcal Infections; Students, Dental

Nasal carriage of antibiotic-resistant Staphylococcus aureus is often used as an index of cross-infection in hospitals. In this paper, a deterministic model of the epidemiology of Staphylococcal nasal carriage was derived employing the concepts of epidemic theory. This theoretical model was tested against experimental data gathered from a large survey. When the association between nasal carriage of tetracycline-resistant Staphylococci and length of stay in hospital derived from the survey was compared with theoretical figures derived from the model, the validity of the model in a real situation was confirmed.

Topics: Carrier State; Cross Infection; England; Female; Humans; Length of Stay; Male; Middle Aged; Models, Theoretical; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Administration, Topical; Carrier State; Fusidic Acid; Humans; Nose; Staphylococcal Infections; Staphylococcus aureus

Infection with strains of methicillin-resistant Staphylococcus aureus occurred in 40 patients at time of admission to a large urban hospital from March to December 1980. Community-acquired methicillin-resistant S. aureus infections occurred in 24 drug abusers and 16 nonabusers. Patients with infections had a longer mean hospitalization and previously had received antimicrobial therapy more frequently than control subjects. Drug abusers with infections had been treated with cephalosporins more often than control subjects (P less than 0.05). Phage typing of 32 isolates showed that 21 were linked by a common phage type (29/52/80/95). Transmission of methicillin-resistant S. aureus from community-acquired cases occurred in the hospital. By January 1981, methicillin-resistant S. aureus accounted for 30.6% of nosocomial S. aureus infections at Henry Ford Hospital. Methicillin-resistant S. aureus infection may arise in the community as well as in the hospital and has the potential to disseminate in both settings.

Topics: Adult; Cross Infection; Disease Outbreaks; Humans; Male; Methicillin; Nose; Staphylococcal Infections; Staphylococcus aureus; Substance-Related Disorders

A patient is described with an orbital fistula complicating frontal sinusitis and osteomyelitis of the frontal bone. The fistula was excised, but a fortnight later an acute exacerbation occurred. From the discharging pus a Staphylococcus aureus was cultured and from mucosa obtained during surgery a microaerophilic Streptococcus. These findings led to the diagnosis: synergistic bacterial inflammation of the frontal sinus, with osteomyelitis and orbital cellulitis.

Topics: Adult; Fistula; Fractures, Bone; Frontal Sinus; Humans; Male; Nose; Orbital Diseases; Osteomyelitis; Radiography; Sinusitis; Skin Diseases; Staphylococcal Infections; Streptococcal Infections

Topics: Adult; Female; Humans; Nose; Postoperative Complications; Rhinoplasty; Shock, Septic; Staphylococcal Infections; Syndrome

Topics: Aged; Carrier State; Cross Infection; Hand Disinfection; Hospital Bed Capacity; Hospitals, Teaching; Humans; Infant, Newborn; Medical Staff, Hospital; Methicillin; Nose; Patient Admission; Patient Isolation; Penicillin Resistance; Staphylococcal Infections; Staphylococcus aureus

Thirty patients undergoing long-term home-based peritoneal dialysis were monitored for 13 months for carriage of Staphylococcus aureus in the nares and for the development of infectious complications. The patients could be divided into three groups with regard to S aureus carriage: chronic, intermittent, and noncarriers. Twenty-five episodes of peritonitis and 20 episodes of catheter exit-site infections occurred during 268 patient-months of observation. Staphylococcus aureus accounted for eight episodes of peritonitis and 12 episodes of exit-site infection. Chronic and intermittent carriers of S aureus were found to be at higher risk of development of infection than noncarriers.

Topics: Adult; Aged; Carrier State; Catheterization; Female; Hemodialysis, Home; Humans; Kidney Failure, Chronic; Male; Middle Aged; Nose; Peritoneal Dialysis; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Prospective Studies; Risk; Staphylococcal Infections; Staphylococcus aureus

Nasal swabs taken from 324 subjects in a Nigerian hospital were examined for the presence of coagulase positive staphylococci. The subjects used in this study included the patients, staff and "auxiliaries" aged from one day to 70 years. The results obtained show that approximately 50% of all the subjects were nasal carriers of Staphylococcus aureus and that age, occupation and length of the subjects' stay in hospital had a significant effect on this figure. It was also found that there is no significant difference between the prevalence of nasal carriage of S. aureus amongst the hospital staff and the patients.

Topics: Adolescent; Adult; Age Factors; Aged; Carrier State; Child; Child, Preschool; Coagulase; Cross Infection; Female; Humans; Infant; Infant, Newborn; Male; Middle Aged; Nigeria; Nose; Sex Factors; Staphylococcal Infections; Staphylococcus aureus

Staphylococcal sepsis is a leading cause of morbidity and mortality among chronic hemodialysis (HD) patients. We studied nasal and cutaneous flora of HD patients and personnel and their patterns of staphylococcal carriage. HD patients had significantly increased cutaneous total bacterial colony counts (p less than 0.01) as well as both nasal (p less than 0.0001) and cutaneous (p less than 0.0001) carriage of Staphylococcus aureus compared to personnel. Cutaneous staphylococcal carriage could be significantly correlated with nasal carriage (p less than 0.01). Cutaneous streptococcal species and gram-negative bacilli were not different between patients and personnel. Staphylococcal phage typing of nasal isolates from staphylococcal carriers revealed a mean of 90% of isolates from each subject belonging to a predominant phage type. Predominant nasal staphylococcal phage types corresponded with respective predominant cutaneous phage types in 93% of HD patients carriers. These studies substantiate autoinoculation of S. aureus from the nasal vestibule to the skin overlying the vascular access site.

Topics: Adolescent; Adult; Carrier State; Female; Hemodialysis Units, Hospital; Humans; Male; Middle Aged; Nose; Personnel, Hospital; Renal Dialysis; Skin; Staphylococcal Infections; Staphylococcus aureus

The nasal carriage rate of Staphylococcus aureus was significantly higher in hospitalized persons (children, adult females and staff) - 53.8%, - than in similar persons at a local clinic - 29.8% (P less than 0.001) - in Ile-Ife, Nigeria. However, unlike studies carried out elsewhere, a higher proportion of S. aureus strains obtained from persons at the clinic were resistant to commonly used antimicrobial agents than were strains isolated in the hospital. This has been attributed to the ease at which these drugs can be obtained by the general population and used unsupervised and indiscriminately. Methicillin was the most effective antimicrobial agent against pathologic staphylococci (2.2% resistance), followed by erythromycin (16.5% resistance), co-trimaxozole (28.0% resistance), chloramphenicol (76.9% resistance), tetracycline (78.6% resistance) and penicillin and ampicillin (97.8% resistance). The widespread resistance of S. aureus to penicillin and ampicillin (and other antimicrobial agents) is of clinical significance in the treatment of post-operative infections, since carriers are reportedly more prone to such infections than are non-carriers.

Topics: Adult; Ambulatory Care Facilities; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Cross Infection; Drug Resistance, Microbial; Female; Humans; Infant; Medical Staff, Hospital; Microbial Sensitivity Tests; Nigeria; Nose; Staphylococcal Infections; Staphylococcus aureus

Topics: Anti-Bacterial Agents; Humans; Nigeria; Nose; Operating Rooms; Personnel, Hospital; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection

Nasal septal abscesses are uncommon. Sixteen cases from the Massachusetts Eye and Ear Infirmary were reviewed retrospectively and are presented. The diagnosis, bacteriology, and pathophysiology are discussed. Immediate therapy is indicated to avoid cosmetic deformity or intracranial infection. Treatment is based on diagnostic needle aspiration, antibiotic coverage and surgical drainage.

Topics: Abscess; Adolescent; Adult; Anti-Bacterial Agents; Child; Child, Preschool; Drainage; Female; Humans; Male; Nasal Septum; Nose; Nose Diseases; Staphylococcal Infections

Aerobic and anaerobic bacterial flora and yeast flora of the nasal vestibule were studied quantitatively in eight persons who were persistent, transient or non-carriers of Staphylococcus aureus. The nasal flora of all the subjects consisted of lipophilic and non-lipophilic aerobic diphtheroids, propionibacteria and different staphylococcal species. Other micro-organisms, such as Pityrosporum and Candida, micrococci, streptococci and coliforms were found only occasionally. The presence of S. aureus was related to diminished numbers of other staphylococcal strains and of propionibacteria.

Topics: Adult; Carrier State; Humans; Nose; Propionibacterium; Skin; Staphylococcal Infections; Staphylococcus aureus

Ten S. aureus strains were each introduced into the nostrils of each of 10 dogs. The dogs retained the strains of S. aureus for the period of the experiment (eight weeks). Five of them with human strain of S. aureus, and the two control dogs acquired S. aureus of canine origin during the period, but no human strain was detected in the nostrils of those into which canine strains were introduced. One of the dogs (dog 4) died during the period of the experiment and both human and canine S. aureus were isolated from its nostrils after the animal had been frozen for about 18 hours. One attendant acquired both canine and human S. aureus during the course of the experiment while one attendant working in he veterinary clinic but had no direct contact with the experimental dogs acquired human S. aureus during the third week of the experiment. It was concluded that contaminated environment jointly being shared by man and animals is the common source of cross contamination by the various biotypes of S. aureus.

Topics: Animals; Disease Reservoirs; Dogs; Drug Resistance, Microbial; Humans; Mercuric Chloride; Mercury; Nose; Occupational Diseases; Staphylococcal Infections; Staphylococcus aureus

Topics: Adolescent; Adult; Aged; Enterobacteriaceae Infections; Escherichia coli; Female; Humans; Male; Middle Aged; Nose; Paranasal Sinuses; Proteus; Sinusitis; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus pyogenes

Over a one-year period 19.5 per cent of 237 patients carried Staphylococcus aureus in their nares preoperatively. This rate was not influenced by the length of hospital stay. The patient nasal carrier state had no correlation with the incidence of postoperative infection. There was no outbreak of S. aureus infection during this period. It is well known that a long preoperative stay greatly increases the risk of infectious complications. This increase in infectious complications was not linked to nasal S. aureus colonization in this study. S. aureus was responsible for 19 per cent of postoperative infections in a 12-month period. S. aureus still occupies a significant place in nosocomial infection rates.

Topics: Carrier State; Cross Infection; Humans; Length of Stay; Nose; Postoperative Complications; Staphylococcal Infections; Staphylococcus aureus

The incidence of Staphylococcus aureus in the nose, throat and superficial wound infections of 99 office staff, 129 psychiatry staff and 115 surgical staff was studied over a 4-week period with the purpose of assessing the potential risk to hospital personnel of staphylococcal infection. Incidence rates, both average and cumulative, were essentially similar in the three groups but certain differences in the ecology of the staphylococcal phage groups were observed. Surgical staff appeared to have a more labile pattern of carriage. As in other Scandinavian studies throat carriage rates were high. Staphylococcal carriage seems largely to depend on individual characteristics rather than environmental factors.

Topics: Adult; Carrier State; Cross Infection; Humans; Microbial Sensitivity Tests; Nose; Occupational Diseases; Personnel, Hospital; Pharynx; Risk; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Sweden; Wound Infection

A comparison was made between the results of phage and lysogenic typing of S. aureus strains isolated during several outbreaks of staphylococcal infection and S. aureus cultures isolated from the same carriers at different periods. The study of the groups of strains having the same origin showed that the differences in the number of reactions were more pronounced in lysogenic typing than in phage typing. For this reason lysogenic typing can be recommended only for the identification of those strains which cannot be identified with the use of the phages of the International Basic Set. The results of the experiments with induced phages proliferating in a restriction-defective strain indicated that restriction and modification were mainly responsible for the specificity of lytic reactions.

Topics: Animals; Bacteriophage Typing; Bronchi; Carrier State; Chickens; Feces; Female; Food Microbiology; Humans; Infant, Newborn; Infant, Newborn, Diseases; Lysogeny; Mastitis; Nose; Poultry Diseases; Pregnancy; Staphylococcal Food Poisoning; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Synovitis

A prospective study of 2983 operations in general and orthopaedic surgery during 3 years performed in four operating theatres in a modern operating suite was carried out in order to evaluate the importance of airborne infection. Weekly nose-and-throat samples were taken from the surgical staff and pre-operative samples were taken from the nose, throat, skin and perineum of the patients. The air contamination was followed by using settle plates, which showed low mean counts of total bacteria of between 9 and 15 c.f.u./m(2)/min, with mean counts of Staph. aureus of between 0.03 and 0.06 c.f.u./m(2)/min. No correlation was found between the total number of bacteria and the incidence of post-operative infections or between the amount of Staph. aureus in the air and post-operative Staph. aureus infections. It was concluded that further increases in ventilation could, at best, only marginally affect the incidence of post-operative infection.The post-operative wound-infection rate was 9.0%. In various types of surgery, the infection rates varied from 5.3% in clean operations to 47.6% in dirty surgery. About one third of the infections were classified as moderate or severe.Adverse patient factors, such as immunodeficiency, steroid treatment, intensive care, etc., increased the rate to 15.0%; in ;normal' patients it was 3.8%.Among the bacteria isolated, gram-negative bacilli (31% of wounds), often together with other bacteria, and Staph. aureus (28%) predominated, but in 25% no specimens were taken.Of 76 post-operative Staph. aureus infections, 32 were caused by the patients' own strains, and of the remaining 44 infections, 22, or 8% of all infections, could be traced to strains present in the air and/or the respiratory tracts of staff during the operation.The length of pre-operative hospital stay had no influence on the carrier rate of Staph. aureus in patients. The incidence of post-operative wound infection was significantly higher in patients carrying Staph. aureus and was even higher if these bacteria were found on the skin.Patients with wound infections stayed, on an average, 15 days longer than patients without infections. In serious infections the increase in duration of stay was > 20 days. Although infections were commoner in older patients, the average additional hospital stay of infected patients did not increase with age. If the post-operative infections studied in a concurrent retrospective study are taken into account more than 12 000 bed-days were d

Topics: Air Microbiology; Bacteriological Techniques; Carrier State; Humans; Length of Stay; Nose; Operating Rooms; Perineum; Personnel, Hospital; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Sweden

Topics: Bacitracin; Cross Infection; Disease Reservoirs; Drug Combinations; Gentian Violet; Hexachlorophene; Humans; Infant Care; Infant, Newborn; Infant, Newborn, Diseases; Missouri; Mothers; Nose; Nurseries, Hospital; Nursing Staff, Hospital; Proflavine; Quaternary Ammonium Compounds; Staphylococcal Infections; Staphylococcus aureus; Umbilical Cord

Nasal swabs were obtained from 408 patients seen in a family practice office in an attempt to identify Staphylococcus aureus carriers. Isolated strains were tested for sensitivity to 11 antibiotics. Study participants were interviewed to obtain the following data: age, history of recent hospitalization and/or recent antibiotic use, number of household members, and occupation, if employed in a health-care facility. S aureus was isolated from 109 nasal swabs. This represents a 26.7 percent carrier rate. Only 25.7 percent of the isolates were sensitive to penicillin G and ampicillin. No statistically significant association was found between the patient variables and either the carrier rate or the sensitivity of the S aureus isolates to penicillin. The sensitivity testing demonstrated that 94.5 percent of the isolates were sensitive to tetracycline and erythromycin. Ninety-nine to 100 percent of the isolates were sensitive to all other antibiotics tested. The authors conclude that penicillin G should not be used in the treatment of S aureus infections. Erythromycin, due to demonstrated sensitivity and reasonable cost, is recommended for mild to moderate infections.

Topics: Adolescent; Adult; Aged; Ampicillin; Anti-Bacterial Agents; Carrier State; Child; Child, Preschool; Erythromycin; Humans; Infant; Middle Aged; Nose; Penicillin G; Penicillin Resistance; Staphylococcal Infections; Staphylococcus aureus; Tetracycline

Topics: Humans; Nose; Operating Rooms; Staphylococcal Infections; Staphylococcus aureus

The incidence of Staphylococcus aureus recovered from cultures of anterior nares was determined for personnel and patients of an obstetric and a neonatal unit. Among the hospital personnel, 10.2% harbored S. aureus. On admission to the hospital, 4% of the obstetric patients were identified as carriers of S. aureus and only 1.3% of the patients acquired the microorganism during hospitalization. The neonates of these mothers with S. aureus were not colonized during hospitalization. Subsequent bacteriophage typing indicated that microbial isolates were primarily in the Group 1 and Group 3 classifications of S. aureus.

Topics: Carrier State; Cross Infection; Female; Humans; Infant, Newborn; Nose; Nurseries, Hospital; Obstetrics and Gynecology Department, Hospital; Personnel, Hospital; Pregnancy; Staphylococcal Infections; Staphylococcus aureus

An epidemic of postoperative wound infections caused by Staphylococcus aureus in 15 patients during a four-month period in 1974 is reported. An unusual staphylococcal antibiogram served as a marker for the multiresistant strain of hospital-acquired infections and raised suspicion of a common source for the infections. The spread of infection began shortly after isolation was discontinued in the index case. An epidemiologic investigation showed that 14 patients were on the same ward, and one patient from another ward had opportunity for contact with the index case. The epidemic was controlled by prompt isolation of all infected patients, adherence to strict isolation techniques, aseptic technique for dressing changes and by treatment of nasal carriers among ward personnel with appropriate antibiotics.

Topics: Anti-Bacterial Agents; California; Carrier State; Cross Infection; Disease Outbreaks; Humans; Nose; Personnel, Hospital; Population Surveillance; Staphylococcal Infections; Staphylococcus aureus; Surgical Wound Infection; Vascular Surgical Procedures

The correlation between Staphylococcus aureus colonization and infection among newborns was studied during a four-year period. Of the 9,423 newborns cultured, 24% were colonized at the time of discharge and in 2% of these an infection developed, whereas only 0.2% of the noncolonized newborns experienced a staphylococcal infection. The weekly colonization rates ranged from 0% to 62%, and outbreaks of infections (two or more concurrent) occurred periodically when the colonization rates ranged from 11% to 57%. Colonization rates per se did not serve as an indicator of an actual or potential outbreak of infection. Instead, the occurrence of two or more concurrent cases of staphylococcal infection or presumptive evidence of an outbreak seems to be a more reliable indicator than colonization monitoring.

Topics: Cross Infection; Disease Outbreaks; Humans; Infant, Newborn; Infant, Newborn, Diseases; Michigan; Nose; Nurseries, Hospital; Population Surveillance; Staphylococcal Infections; Staphylococcus aureus; Umbilicus

We studied the carriage rate of Staphylococcus aureus in patients receiving long-term hemodialysis and also noted the incidence of shunt infections, bacteremia, and septicemia in colonized patients. Thirty-one of 50 patients (62%) carried S aureus in the nose, throat, or on the skin, of whom 20 patients developed shunt infections; nine infections resulted in episodes of bacteremia. Patients with chronic renal failure not undergoing hemodialysis had a 21% carriage rate. Thus, there is a high carriage rate of S aureus in asymptomatic patients receiving hemodialysis that is probably related to an increased incidence of shunt infections and bacteremia.

Topics: Adult; Aged; Carrier State; Female; Humans; Male; Middle Aged; Nose; Pharynx; Renal Dialysis; Sepsis; Skin; Staphylococcal Infections; Staphylococcus aureus

78 Staphylococci isolated from mouth, throat, nose, ear passages and skin lesions were typed with 22 basic phage types. 68 of 78 staphylococci were typed. 45 of these (66%) could be typed with RTD, and 23 (33.8%) with 1000 X RTD. When phage grouping is considered, 14 out of 68 strains were from Group III and 12 out of 52 strains isolated from nose were from Group I phage.

Topics: Bacteriophage Typing; Ear; Humans; Mouth; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages

A herd of cattle with a history of increased prevalence of clinical and nonclinical mastitis was investigated. Bacteriologic analysis of milk samples indicated approximately 50% of the herd was producing milk containing coagulase-positive staphylococci. Of these staphylococcal isolates, 55% had characteristics consistent with those of human strains of staphylococci, based on hemolysin production and phage patterns. Human beings in contact with the herd were nasal carriers of these staphylococci, which produced a granulartype coagulase reaction in bovine plasma, rather than the usually expected clot-type reaction. In the herd, the staphylococci caused mainly nonclinical mastitis, which was largely unresponsive to antibiotic therapy.

Topics: Animals; Bacteriophage Typing; Carrier State; Cattle; Coagulase; Deoxyribonucleases; Female; Hemolysin Proteins; Humans; Mastitis, Bovine; Milk; Nose; Staphylococcal Infections; Staphylococcus aureus

Samples from blowhole and pharynx of 1 dolphin ill with a respiratory tract infection and 31 healthy dolphins at 2 oceanariums were examined by bacteriologic cultural technique. During the same period, nasal and volar forearm skin samples were collected from 32 healthy personnel and from a furuncle on the forearm of 1 attendant. Coagulase-positive staphylococci were isolated from 8 dolphins (including the ill dolphin) and from 14 persons. Antibiotic sensitivity patterns (8 drugs were tested) differed markedly for the staphylococcal isolates recovered from dolphins, as compared with those from persons. Staphylocci from the dolphins were totally or partially sensitive to every antibiotic, whereas almost all of the isolates from persons were resistant to penicillin and ampicillin, as well as to certain other antibiotics. Staphylococcus bacteriophage typing revealed that only 1 isolate from a dolphin could be typed (type D11). Six of the isolates from persons were typable, but no isolate was sensitive to only type D11. It was concluded that, although Staphylococcus aureus could be isolated commonly from captive dolphins, there was no evidence of cross infection between the dolphins and the oceanarium personnel.

Topics: Animals; Anti-Bacterial Agents; Dolphins; Drug Resistance, Microbial; Humans; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus Phages; Zoonoses

Topics: Catheterization; Duodenum; Enteral Nutrition; Enterocolitis, Pseudomembranous; Humans; Infant Food; Infant, Newborn; Infant, Newborn, Diseases; Nose; Prospective Studies; Staphylococcal Infections; Staphylococcus aureus; Stomach

Neonatal staphylococcal disease occurred in the nurseries of a university hospital three weeks after discontinuation of routine, daily, whole-body bathing of newborns with hexachlorophene. Of 16 infants who had clinical manifestations within a two-week period, 11 cases were confirmed bacteriologically. Shortly after onset of the outbreak, daily clinical and microbiologic surveillance and control measures on all infants and personnel were inaugurated. Clinical surveillance after the outbreak did not yield any new case. Average incidence of cultures positive for coagulase-positive Staphylococcus aureus was highest (13% per week) during the first three weeks of microbiologic surveillance (when hexachlorophene was not used). This is lower than that reported in most previous studies. These findings indicate the importance of scrupulous hand washing before and after handling each infant and of enforcement of other basic nursery techniques.

Topics: Baths; Conjunctiva; Conjunctivitis; Cross Infection; Female; Fingers; Hexachlorophene; Humans; Infant Care; Infant, Newborn; Infant, Newborn, Diseases; Male; Nose; Nurseries, Hospital; Nursing Staff, Hospital; Pneumonia; Soaps; Staphylococcal Infections; Staphylococcus Phages; Time Factors; Umbilicus

Studies in a newly built hospital furnished with complete air conditioning where most of the patients are nursed in 6-bed rooms showed that the transfer of air from one patient room to another was very small, especially when there was substantial flow of air in a consistent direction between the patient rooms and the corridor, and that the direct transfer of airborne particles was even less. There was, however, no evidence of any reduction in the rates of nasal acquisition of Staphylococcus aureus compared with those to be found in naturally ventilated hospitals. The numbers of Staph. aureus found in the air of a given room that appeared to have originated from patient carriers in other rooms were many times greater than could be accounted for by direct airborne transfer. Although there was evidence that many carriers were not detected, detailed study showed that this excess transfer to the air of other rooms was genuine. It seems probable on the basis of investigations in this hospital and elsewhere that this excess transfer occurs indirectly, through dispersal from the clothing of the nursing and medical staff into the air of another room of strains with which their outer clothes have become contaminated while dealing with patients. Reduction in direct airborne transfer of micro-organisms from one room to another, whether by ventilation or other means, can only be of clinical advantage if transfer by other routes is, or can be made, less than that by the direct airborne route.

Topics: Adult; Aged; Air Conditioning; Air Microbiology; Carrier State; Cross Infection; Environmental Exposure; Female; Humans; Length of Stay; London; Male; Middle Aged; Nose; Staphylococcal Infections; Staphylococcus aureus

The hands of 50 nurses and 50 controls were tested for coagulase-positive staphylococcus. Twenty-eight percent of both groups were carriers. The mean staphylococcal count on the palm of the hand was 13.7 per 16 cm-2 in nurses as compared to 442.7 per 16 cm-2 in the control group. The number of persistent carriers was the same for each group, but 25 percent of all cultures from nurses were positive for Staphylococcus aureus as compared to 14.2 percent of the cultures from the control group. It was concluded that there was no direct correlation between high staphylococcal counts and persistence of carriage. The skin as a site of carriage of Staphylococcus aureus was found to be of greater importance in nurses than in control subjects.

Topics: Anti-Bacterial Agents; Bacteriophage Typing; Carrier State; Culture Techniques; Female; Hand; Humans; Microbial Sensitivity Tests; Nails; Nose; Nurses; Pharynx; Skin; Staphylococcal Infections; Staphylococcus

Important populations of Staphylococcus aureus were found to be present on the body surfaces of live poultry originating from flocks without history of staphylococcal disease. Their sized increased considerably until approximately the seventh week of life after which time they were maintained at equally high levels. Significant correlations were found between the populations recovered from superficial wash samples and skin-tissue samples. Similarly the numbers isolated from the nasal cavities were correlated with other surface counts. Low numbers were present in the intestinal tract. Birds with staphylococcal synovitis had higher numbers in all sampling regions. The counts were very high in subjects suffering from staphylococcal dermatitis. Higher rates of positive birds and higher numbers of staphylococci were detected with a whole body sampling method than with a nasal swab technique. The isolates obtained in this study belonged to the S. aureus biotype B which is associated with poultry and pigs.

Topics: Animals; Chickens; Dermatitis; Female; Intestines; Nose; Poultry Diseases; Skin; Staphylococcal Infections; Staphylococcus; Synovitis

An outbreak of streptococcal and staphylococcal skin disease was discovered in a full-term nursery after the discontinuation of bathing infants with hexachlorophene. The epidemic was only temporarily controlled by conventional means and recurred despite reinstitution of hexachlorophene bathing. Measures that decreased infants' exposure to visitors and hospital personnel and enforced aseptic techniques in the nursery were more important than use of hexachlorophene soap in achieving and maintaining control.

Topics: Anti-Bacterial Agents; Antisepsis; Cross Infection; Disease Outbreaks; Hexachlorophene; Humans; Infant, Newborn; Infant, Newborn, Diseases; North Carolina; Nose; Nurseries, Hospital; Recurrence; Skin Diseases; Staphylococcal Infections; Streptococcal Infections; Umbilical Cord

To determine the source of pyococci causing attacks of sepsis in infantile eczema 20 patients with continuing eczema were followed up for one year, regular swabs being taken from the skin, nose, throat, and family contacts. The staphylococci were phage typed and the streptococci serologically typed. Staphylococci of the same phage type in most cases remained in reservoir sites on the skin and coincidently in the nose. Staphylococci causing attacks of clinical sepsis arose from these persistently colonized sites. Staphylococci of the same phage type were also common in family contacts. Streptococci of the same group in most cases did not remain on the skin. Streptococci causing attacks of clinical sepsis arose as new infections from external sources, sometimes from throat infections in the patient or family contacts. Strains of streptococci which are known to be associated with glomerulonephritis were isolated. It has been confirmed that staphylococci resistant to neomycin and sodium fusidate quickly emerge after the topical use of these antibiotics. Streptococci are highly resistant to neomycin and gentamicin, and moderately resistant to sodium fusidate, so the use of these antibiotics in topical steroid preparations will have little effect in preventing further attacks of clinical sepsis in these patients.

Topics: Adolescent; Child; Child, Preschool; Dermatitis, Atopic; Disease Reservoirs; Drug Resistance, Microbial; Follow-Up Studies; Fusidic Acid; Gentamicins; Humans; Infant; Neomycin; Nose; Pharynx; Skin; Staphylococcal Infections; Streptococcal Infections

Topics: Administration, Oral; Adolescent; Adult; Aged; Carrier State; Diabetes Complications; Diabetes Mellitus; Female; Humans; Injections; Insulin; Male; Middle Aged; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus

Topics: Adult; Air Microbiology; Carrier State; Clothing; Cross Infection; Female; General Surgery; Gossypium; Humans; Male; Middle Aged; Nose; Operating Rooms; Perineum; Personnel, Hospital; Polyethylenes; Sex Factors; Skin; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection; Ventilation; Workforce

Topics: Carrier State; Chile; Food Handling; Health Education; Humans; Nails; Nose; Pharynx; Restaurants; Staphylococcal Food Poisoning; Staphylococcal Infections

Topics: Adolescent; Adult; Bacteriocins; Child; Coagulase; Fibrinolysin; Hemolysis; Humans; Middle Aged; Muramidase; Nose; Penicillin Resistance; Pharynx; Phospholipases; Skin; Staphylococcal Infections; Staphylococcus

Topics: Antibiosis; Carrier State; Environment; Female; Humans; Nose; Staphylococcal Infections; Staphylococcus

A strain of Staphylococcus aureus resistant to as many as nine distinct antibiotics has shown unusally high virulence as indicated by its ability to cause an epidemic of furunculosis amongst hospital nurses.

Topics: Bacteriophage Typing; Burns; Cross Infection; Disease Outbreaks; Drug Resistance, Microbial; Female; Furunculosis; Humans; Nose; Skin Diseases, Infectious; Staphylococcal Infections; Staphylococcus; Virulence

Topics: Abdomen; Cerebrospinal Fluid Shunts; Ear, External; Humans; Hydrocephalus; Neck; Nose; Postoperative Complications; Scalp; Sepsis; Staphylococcal Infections; Surgical Wound Infection; Time Factors

Topics: Carrier State; Cross Infection; Humans; Nose; Operating Rooms; Personnel, Hospital; Staphylococcal Infections

Topics: Adolescent; Adult; Age Factors; Aged; Antigen-Antibody Reactions; Child; Eye; Fluorescent Antibody Technique; Humans; Middle Aged; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus; Stevens-Johnson Syndrome; Syndrome

Topics: Carrier State; Child, Preschool; Diseases in Twins; Humans; Nose; Staphylococcal Infections; Staphylococcus

The wound infection rates, nasal carriage rates, and nasal colonization rates were studied in a recently built surgical unit for two years when it was first opened. Five years later a further two-year period of study was undertaken.Judging by the incidence of postoperative wound infection, as far as both Staphylococcus pyogenes and Gram-negative organisms are concerned, there is no evidence that the environment has become less safe with use over the seven-year period since opening.

Topics: Bacteria; Cross Infection; Hospital Design and Construction; Hospital Units; Humans; Nose; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection; Ventilation

Topics: Age Factors; Carrier State; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Nasal Mucosa; Nose; Staphylococcal Infections; Staphylococcus

Topics: Blood; Cerebrospinal Fluid; Classification; Deoxyribonucleases; Endopeptidases; Fermentation; Hemolysin Proteins; Humans; Mannitol; Models, Biological; Muramidase; Nose; Pepsin A; Phosphoric Monoester Hydrolases; Skin; Staphylococcal Infections; Staphylococcus; Suppuration; Urease; Urine

Topics: Breast; Carrier State; Cross Infection; Disease Reservoirs; Erythromycin; Female; Hospital Departments; Humans; Infant, Newborn; Medical Staff; Nose; Obstetrics; Penicillin G; Penicillin Resistance; Staphylococcal Infections; Staphylococcus; Streptomycin; Surveys and Questionnaires; Tetracycline

The dispersal of Staphylococcus aureus from burned patients, the relation between nasal carriage by the staff and exposure to airborne Staph. aureus, and the transfer of Staph. aureus-carrying particles within the ward have been studied. The dispersal of Staph. aureus from burned patients was correlated to the size of the burn wound. The median values varied from 21 c.f.u./m.(2)/hr. for patients with small burns to 453 c.f.u./m.(2)/hr. for extensively burned patients. The size of the dispersed particles appeared to be smaller than that usually found in hospital wards. Carriage of nasal strains by the staff was correlated to the air counts; the number of patient sources did not seem to be of great importance. The transfer of Staph. aureus within the ward was at least 6 to 20 times that which would have been expected if transfer was due to air movement only.

Topics: Air Microbiology; Air Movements; Burns; Carrier State; Cross Infection; Hospital Design and Construction; Hospital Units; Humans; Nose; Patient Isolators; Perineum; Pharynx; Skin; Staphylococcal Infections; Staphylococcus

Topics: Bacteriological Techniques; Cross Infection; Economics, Hospital; Evaluation Studies as Topic; Female; Hospital Administration; Hospital Units; Humans; Infant, Newborn; Infant, Newborn, Diseases; Nose; Obstetrics; Patient Isolators; Poland; Staphylococcal Infections; Staphylococcus

Topics: Anesthesia, Inhalation; Bacteriological Techniques; Child; Child, Preschool; Epiglottis; Haemophilus; Haemophilus influenzae; Humans; Intubation, Intratracheal; Laryngitis; Length of Stay; Nose; Staphylococcal Infections; Streptococcal Infections; Streptococcus pyogenes; Time Factors

Topics: Drainage; Ear; Ear, External; Feces; Female; Humans; Infant; Kanamycin; Nose; Punctures; Staphylococcal Infections; Staphylococcus; Thorax

Topics: Adult; Carrier State; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Nose; Perineum; Personnel, Hospital; Staphylococcal Infections; Staphylococcus; Time Factors; Umbilicus

Topics: Aerosols; Air Conditioning; Air Microbiology; Bacteriophage Typing; Burns; Cell Count; Cross Infection; Disease Outbreaks; Hospital Units; Humans; Models, Biological; Nose; Perineum; Pharynx; Potassium Iodide; Skin; Staphylococcal Infections; Staphylococcus

Topics: Carrier State; Cross Infection; England; Equipment and Supplies, Hospital; Female; Hospitals, Teaching; Humans; Male; Methicillin; Microbial Sensitivity Tests; Nose; Patients; Personnel, Hospital; Staphylococcal Infections; Sterilization; Tetracycline

Topics: Animals; Bacteriophage Typing; Coagulase; Dog Diseases; Dogs; Fibrinolysin; Fibrinolysis; Hemagglutination; Hemagglutination Tests; Humans; Nose; Staphylococcal Infections; Staphylococcus; Staphylococcus Phages

Topics: Anti-Bacterial Agents; Bacteriophage Typing; Boston; Carrier State; Cross Infection; Hip; Hospitalization; Humans; Middle Aged; Nose; Orthopedics; Patient Isolators; Pharynx; Prospective Studies; Staphylococcal Infections; Staphylococcus; Staphylococcus Phages; Surgical Wound Infection; Urinary Catheterization

Topics: Carrier State; Cross Infection; Drug Resistance, Microbial; Humans; Nose; Staphylococcal Infections; Staphylococcus; Staphylococcus Phages; Surgical Procedures, Operative; Surgical Wound Infection

Topics: Carrier State; Cross Infection; Hospital Design and Construction; Humans; Nose; Pharynx; Staphylococcal Infections

Topics: Aerosols; Air Microbiology; Anti-Bacterial Agents; Carrier State; Cross Infection; Hand; Hexachlorophene; Humans; Nose; Perineum; Pharynx; Staphylococcal Infections

Topics: Adult; Anti-Bacterial Agents; Anti-Infective Agents, Local; Carrier State; Female; Furunculosis; Humans; Male; Nose; Perineum; Staphylococcal Infections

Topics: Adolescent; Adult; Age Factors; Aged; Carrier State; Child; Child, Preschool; Cross Infection; Drug Resistance, Microbial; Escherichia coli; Female; Hospitalization; Humans; Infant; Intestines; Male; Microbial Sensitivity Tests; Middle Aged; Nose; Rectum; Staphylococcal Infections; Staphylococcus

Topics: Bacteriological Techniques; Bacteriophage Typing; Burns; Chloramphenicol; Coagulase; Erythromycin; Humans; Hyperbaric Oxygenation; Methicillin; Microbial Sensitivity Tests; Nose; Penicillin G; Skin; Staphylococcal Infections; Staphylococcus; Streptomycin; Tetracycline; Wound Infection

The use of plastic isolators and of an ;air curtain' isolator for protection of patients against infection was studied in a burns unit.Preliminary bacteriological tests showed that very few airborne bacteria gained access to a plastic ventilated isolator; even when the filter and pre-filter were removed from the air inflow, settle-plate counts inside the isolator were much lower than those in the open ward, but the difference was smaller in tests made with an Anderson air sampler, which showed also that fewer large bacteria-carrying particles appeared inside the isolator than outside it. An open-topped isolator allowed virtually free access of bacteria from ambient air. The numbers of airborne bacteria inside an air curtain were appreciably lower than the counts of airborne bacteria in the open ward, but not as low as those in the plastic ventilated isolator.Controlled trials of isolators were made on patients with fresh burns of 4-30% of the body surface; the patients were given no topical chemoprophylaxis against Staphylococcus aureus or Gram-negative bacilli. Patients treated in plastic isolators showed a significantly lower incidence of infection with Pseudomonas aeruginosa than those treated in the open ward; this protective effect was shown by isolators with or without filters or with an open top. Ventilated isolators, which protected patients against personal contact and airborne infection, gave a limited protection against multi-resistant ;hospital' strains of Staph. aureus, but no such protection was given by an open-topped isolator, which protected only against personal contact infection, or by air curtains, which protected only against airborne infection; the air curtain gave no protection against Ps. aeruginosa, and there was no evidence of protection by any isolator against Proteus spp. and coliform bacilli.Both the controlled trials and evidence from the bacteriology of air, hands, fomites and rectal and nasal swabs taken on admission and later, supported the view that Ps. aeruginosa is transferred mainly by personal contact, Staph. aureus probably by air as well as by contact and coliform bacilli mainly by self infection with faecal flora, many of which are first acquired from the hospital environment in food or on fomites.The use of plastic isolators is cumbersome, and of limited value except in the control of infection with Ps. aeruginosa. For this reason and because of the effectiveness of topical chemoprophylaxis such isolators are unli

Topics: Air Microbiology; Burns; Child; Cross Infection; Drug Resistance, Microbial; Feces; Hand; Hospital Departments; Humans; Nose; Patient Isolators; Plastics; Proteus; Pseudomonas aeruginosa; Pseudomonas Infections; Rectum; Staphylococcal Infections

Topics: Aerosols; Air Microbiology; Anti-Bacterial Agents; Carrier State; Cross Infection; Drug Resistance, Microbial; Hospitals, General; Humans; Nose; Operating Rooms; Personnel, Hospital; Staphylococcal Infections; Staphylococcus; Ventilation

Topics: Adolescent; Adult; Chronic Disease; Female; Humans; Male; Middle Aged; Nose; Palatine Tonsil; Rhinitis, Allergic, Seasonal; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus; Tonsillectomy; Tonsillitis

Topics: Child; Child, Preschool; Diagnosis, Differential; Erythromycin; Face; Female; Humans; Lymphadenitis; Male; Neck; Nose; Staphylococcal Infections; Suppuration

Topics: Bacitracin; Burns; Chloramphenicol; Cross Infection; Erythromycin; Fusidic Acid; Humans; Methicillin; Microbial Sensitivity Tests; Neomycin; Nose; Novobiocin; Penicillin Resistance; Penicillins; Staphylococcal Infections; Staphylococcus; Streptomycin; Tetracycline

Rapid spread of methicillin-resistant staphylococci (MeRS) in a children's hospital is described. Within 4 months of the first isolation MeRS had been isolated from infections in all clinical units. MeRS were also regularly isolated at the out-patient department. Protective isolation of one of the clinical units had no effect on the infection rate by MeRS. The use of antiseptics (Hexachlorophene and chlorhexidine) and gentamicin nose cream in children and staff members in three out of five clinical units resulted in a significant reduction of the prevalence of nose colonization by MeRS in children. In staff members a non-significant reduction of the prevalence of colonization and a significant reduction of the acquisition of MeRS was found. After a few months the infection rate decreased to zero in the units where the measures were introduced. It remained unchanged in the other units. Phage typing of two sets of strains collected at an interval of 6 months showed that the infections were mainly caused by two endemic strains of MeRS. The majority of the infections caused by MeRS was of minor importance. In 16% of the infections a strain was isolated repeatedly and for more than 1 week. After the introduction of antiseptics a relative increase of infections by Gram-negative bacteria was observed. The significance of this phenomenon is discussed.

Topics: Anti-Infective Agents, Local; Bacteriophage Typing; Child, Preschool; Cross Infection; Gentamicins; Hexachlorophene; Humans; Infant; Infant, Newborn; Methicillin; Nose; Penicillin Resistance; Staphylococcal Infections

Studies on infections in a hospital for diseases of the skin are described. Patients were shown to acquire staphylococci in the groin and on the chest at about the same rate as in the nose. In contrast to surgical wards, many staphylococci were resistant to tetracycline but sensitive to penicillin. Nevertheless, much of the epidemic spread of staphylococci was with typical surgical-ward strains rather than with phage group II strains which might be thought typical of skin diseases.

Topics: Anti-Bacterial Agents; Carrier State; Cross Infection; Disease Outbreaks; Hospitals, Special; Humans; Nose; Penicillin Resistance; Penicillins; Skin; Skin Diseases; Staphylococcal Infections; Staphylococcus; Tetracycline; Thorax

Topics: Arthritis, Rheumatoid; Conjunctiva; Eye; Eyelids; Female; Humans; Keratoconjunctivitis; Male; Middle Aged; Nose; Penicillin Resistance; Staphylococcal Infections

Topics: Carrier State; Female; Humans; Nose; Staphylococcal Infections; Staphylococcus

Topics: Aerosols; Animals; Antigens, Bacterial; Carrier State; Hypersensitivity, Delayed; Mice; Nose; Skin Tests; Staphylococcal Infections; Staphylococcus

Topics: Hand; Humans; Intestines; Masks; Nose; Operating Rooms; Personnel, Hospital; Skin; Staphylococcal Infections; Staphylococcus; Sterilization; Surgical Wound Infection

Topics: Air Microbiology; Bacteria; Carrier State; Cross Infection; Humans; Nose; Personnel, Hospital; Postoperative Complications; Staphylococcal Infections; Staphylococcus; Suppuration; Surgical Wound Infection

Topics: Carrier State; Cross Infection; Drug Resistance, Microbial; Hexachlorophene; Humans; Microbial Sensitivity Tests; Nose; Ointments; Penicillin Resistance; Proteus; Pseudomonas aeruginosa; Staphylococcal Infections; Staphylococcus

The nasal flora of coagulase-positive staphylococcus carriers and noncarriers was studied in aerobic conditions in 17 individuals. Five hundred milligrams of cephalexin was given orally four times daily for 12 days, and its effects on the nasal bacteria were determined quantitatively before, during, and after treatment. The total count obtained before the drug treatment was 5.4 x 10(6) in carriers and 3.9 x 10(6) in noncarriers. The lowest total count observed was 3 days after the cessation of the drug. The increase in gram-negative rods was seen 9 days after antibiotic therapy, not during the greatest reduction of gram-positive bacteria. Coagulase-positive cocci and diphtheroids were most sensitive to drug treatment. After 36 days, the total count was restored to pretreatment level. Diphtheroids did not return to the original number and were replaced by a corresponding increase of resistant coagulase-negative cocci. An inverse relationship between coagulase-negative cocci and lipophilic diphtheroids was seen in the anterior nares of many individuals. No gross difference in nasal ecology to differentiate carriers from noncarriers was seen.

Topics: Administration, Oral; Bacteria; Bacteriological Techniques; Carrier State; Cephalosporins; Humans; Male; Nose; Staphylococcal Infections

Topics: Adolescent; Adult; Aged; Bronchi; Cadaver; Fluorescent Antibody Technique; Humans; Influenza, Human; Lung; Middle Aged; Nose; Postmortem Changes; Staphylococcal Infections; Time Factors; Trachea

Topics: Air Microbiology; Carrier State; Chloramphenicol; Cross Infection; Dust; Germany, East; Hand; Humans; Nose; Penicillin Resistance; Penicillins; Pharynx; Staphylococcal Infections; Staphylococcus; Sterilization; Streptococcal Infections; Streptococcus; Streptomycin; Surgical Wound Infection; Tetracycline

An investigation of staphylococcal epidemiology was undertaken at an Australian National Antarctic Research Expedition station during 1965-1966. It concerned the carriage of staphylococci by the men and their dogs, and the occurrence of staphylococci in the station environment. The year-long study indicated that coagulase-negative strains survived better in the Antarctic environment than coagulase-positive strains. It was demonstrated that naturally acquired coagulase-positive strains could not maintain colonization on forearm skin under the usual cold exposure experienced at Mawson station, though coagulase-negative skin strains appeared to thrive during the winter. Staphylococcus albus and S. aureus were able to persist in the anterior nares, despite the sometimes lower temperatures recorded in this micro-climate, probably because of the greater humidity and denser populations found there. The majority of the nasal carriers of S. aureus were persistent carriers, only two men in 27 being found to be occasional carriers of nasal strains, which was consistent with the observation that transfer of this pathogen from man to man is not common under Antarctic conditions. Half of the 27 sledge dogs at the station were found to carry coagulase-positive staphylococci but this did not appear to be of pathological significance to their human handlers. The local inanimate environment, including mess hut, sleeping huts and sleeping bags used on expeditions, was searched for contamination by S. aureus but none was detected.

Topics: Air Microbiology; Animals; Antarctic Regions; Carrier State; Dog Diseases; Dogs; Humans; Male; Nose; Pharynx; Skin; Staphylococcal Infections; Staphylococcus

An investigation was made of nasal acquisition of Staphylococcus aureus and of staphylococcal wound sepsis in a hospital ward divided into two sections and provided with mechanical ventilation, so that there was no transfer of air from one of the sections to the other. Although the strains of S. aureus found in the air, and those colonizing the noses of patients, in the protected section could seldom be related to patients nursed elsewhere in the ward, the mechanical ventilation did not lead to any significant reduction in the degree of contamination of the air or in the rate of nasal acquisition of S. aureus.Even in the protected section, nearly 20% of the strains of S. aureus recovered from the air could not be related to known nasal carriers. Since this proportion was nearly as great as that found in the absence of directed air-flow, it seems probable that these strains were derived either from undetected sources within the section or were dispersed from the clothes of persons who entered it.Nearly one-third of the nasal acquisitions in the ward could not be related to known nasal carriers, but about one-half of these (16%) were probably ;spurious' and half of the remainder (8%) could be related to strains recovered from patients' lesions or drawsheets, leaving no more than 8% unaccounted for. A short investigation in which both drawsheet and perineal samples were examined showed that drawsheet samples did not give a reliable indication of perineal carriage unassociated with nasal carriage.During the period of the investigation, a single strain of S. aureus that was resistant to a wide range of antibiotics established itself in the ward. The most notable character of this strain was the profuse dispersion of it by carriers. As a consequence, staphylococcal wound sepsis increased, with nearly three-quarters of the infections attributable to this strain, and nasal carrier rates increased with length of stay in the ward, over 20% of patients who stayed 5-6 weeks acquiring the strain.

Topics: Air Microbiology; Cross Infection; Drug Resistance, Microbial; Hospital Design and Construction; Humans; Male; Nose; Staphylococcal Infections; Staphylococcus; Ventilation

The spread of Staphylococcus aureus was studied in three general surgical wards of identical design which consisted of a number of separate rooms, and the results were compared with those in the same unit previously studied, in subdivided wards elsewhere and in large open wards.The nasal carrier rate of Staph. aureus by patients rose during their stay in the ward, but its peak rate was comparable with minimum rates reported in other subdivided wards and was lower than in open wards.Staphylococcal sepsis rates were lower than in most open wards and were also much lower than those found previously in the same unit when overcrowding was common and each sex had its own ward.

Topics: Air Microbiology; Cross Infection; Crowding; Drug Resistance, Microbial; Female; Hospital Design and Construction; Humans; Male; Nose; Postoperative Care; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection

Topics: Aged; Carrier State; Cross Infection; Disease Outbreaks; Female; Hospitals, General; Humans; Male; Methicillin; Microbial Sensitivity Tests; Middle Aged; Nose; Nursing Homes; Penicillin Resistance; Pneumonia, Staphylococcal; Staphylococcal Infections; Staphylococcus; Wound Infection

Topics: Carrier State; Culture Media; Drug Resistance, Microbial; Humans; Mass Screening; Nose; Staphylococcal Infections; Staphylococcus

Topics: Bacteriophage Typing; Cross Infection; Disease Outbreaks; Housekeeping, Hospital; Humans; Infant, Newborn; Maternal Health Services; Nose; Obstetric Nursing; Staphylococcal Infections; Staphylococcus; Umbilical Cord

Topics: Carrier State; Female; Humans; Male; Nose; Skin; Staphylococcal Infections; Staphylococcus; Surgical Wound Infection

Topics: Animals; Biology; Cross Infection; Fatty Acids; Humans; Impetigo; Infant, Newborn; Lipase; Mice; Nose; Skin; Staphylococcal Infections; Staphylococcus; Toxins, Biological

Topics: Baths; Child Health Services; Clothing; Cross Infection; Hand; Hexachlorophene; Hospital Departments; Humans; Hygiene; Infant, Newborn; Infant, Newborn, Diseases; Nose; Personnel, Hospital; Staphylococcal Infections; Staphylococcus; Sterilization

Topics: Anti-Bacterial Agents; Carrier State; Coagulase; Female; Humans; Nose; Organophosphonates; Staphylococcal Infections; Staphylococcus