rifampin and Gram-Positive-Bacterial-Infections

This review summarizes the in vitro and animal model data available on antibiotic combinations with daptomycin. The majority of studies focus on the clinically relevant combinations of daptomycin with rifampicin or with gentamicin. These studies demonstrate that daptomycin does not adversely affect the activity of other antimicrobial agents that may be administered concomitantly. Overall, additive or indifferent effects with daptomycin combinations were observed; however, synergy was observed for certain isolates of vancomycin-resistant enterococci when exposed to daptomycin and rifampicin. Unexpected synergy was demonstrated against methicillin-resistant Staphylococcus aureus by daptomycin and beta-lactams. Most importantly, no in vitro antagonism of daptomycin with any other agent tested was confirmed in these studies. The most striking in vivo effects were noted in two different complicated infection models; i.e. osteomyelitis and implant infections, where rifampicin combinations with daptomycin increased efficacy and reduced the incidence of rifampicin resistance.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Daptomycin; Disease Models, Animal; Drug Interactions; Drug Therapy, Combination; Gentamicins; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Rifampin

We reviewed the bibliographic evidence from comparative trials regarding the role of rifampin as adjuvant treatment in the treatment of Gram-positive infections [PubMed (1/1950-7/2006)]. Only studies reporting comparative outcome data in patients treated with an antibiotic regimen with the addition or not of rifampin were included. Eight comparative studies were identified [all were randomized controlled trials (RCTs)], five reporting on infections caused by staphylococci (S. aureus in 97% of patients) and three by streptococci. There was no statistically significant difference in mortality between the treatment arms (with and without rifampin) in any of the included studies. Clinical cure was achieved more commonly (p < 0.05) in the rifampin treatment arm in 3/8 studies; in staphylococcal infections of orthopedic stable implants and in beta-hemolytic streptococcal pharyngitis in children (one RCT each), and in one RCT that reported on patients with various staphylococcal infections. However, no statistically significant difference in cure of the infection between the two groups was found after pooling data from two RCTs (121 patients) that reported on patients with various staphylococcal infections (odds ratio = 0.57; 95% confidence interval 0.27-1.17). No differences were noted between the two groups regarding relapse of infection or adverse events. There is only limited evidence from comparative trials regarding the role of rifampin as adjuvant therapeutic agent for infections caused by Gram-positive bacteria, not allowing for definitive conclusions on this important management question. More controlled trials are necessary for better evaluation of this practice.

Topics: Anti-Bacterial Agents; Clinical Trials as Topic; Gram-Positive Bacterial Infections; Humans; Rifampin

Treatment of Gram-positive osteoarticular infections requires an adequate surgical approach combined with intensive antimicrobial therapy. The aim of this study was to evaluate the safety and efficacy of a combined regimen of high-dose daptomycin and rifampicin, in patients with various types of Gram-positive osteoarticular infections.. This single centre, non-comparative, prospective study evaluated the safety and efficacy of a combined regimen of intravenous daptomycin (8 mg/kg/day) and oral rifampicin (600 mg/day) in patients with Gram-positive osteoarticular infections, with a minimal follow-up of one year. Creatine phosphokinase, transaminases, bilirubinaemia, and serum creatinine, were measured at baseline and regular intervals.. The median daily doses of daptomycin and rifampicin, administered for a median duration of 21 (range, 10-122) days to 16 patients (median age, 63.5 years; 11 males, five females) presenting with staphylococcal (n = 15) or streptococcal (n = 1) osteoarticular infections, were 8.15 (range, 6.6-8.9) mg/kg/day and 600 (range, 600-900) mg/day, respectively. The combined regimen of daptomycin and rifampicin was well tolerated by all except one patient, without requiring treatment adjustment or discontinuation. One patient developed allergic responses probably due to rifampicin after 42 days. Fifteen (94 %) patients showed favourable clinical and microbiological outcomes.. The combined regimen of high-dose daptomycin and rifampicin was well tolerated and may provide a useful alternative to standard glycopeptide therapy for Gram-positive osteoarticular infections.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Daptomycin; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Follow-Up Studies; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Osteoarthritis; Prospective Studies; Prosthesis-Related Infections; Rifampin; Treatment Outcome

Both linezolid and cotrimoxazole are antibiotics that are well suited for oral therapy of bone and joint infections (BJI) caused by otherwise resistant Gram-positive cocci (GPC) (resistance to fluoroquinolones, maccolides, betalactamines). However, in this context, no data are currently available regarding the safety and tolerance of these antibiotics in combination with rifampicin. The objective of this study was to compare the efficacy and safety of a combination of rifampicin and linezolid (RLC) with those of a combination of rifampicin and cotrimoxazole (RCC) in the treatment of BJI. Between February 2002 and December 2006, 56 adult patients (RLC, n = 28; RCC, n = 28), including 36 with infected orthopaedic devices (RLC, n = 18; RCC, n = 18) and 20 with chronic osteomyelitis (RLC, n = 10; RCC, n = 10), were found to be eligible for inclusion in this study. Patients who discontinued antibiotic therapy within 4 weeks of commencing treatment were considered to represent cases of treatment failure and were excluded. Rates of occurrence of adverse effects were similar in the two groups, at 42.9% in the RLC group and 46.4% in the RCC group (p = 1.00), and led to treatment discontinuation in four (14.3%) RLC and six (21.4%) RCC patients. Cure rates were found to be similar in the two groups (RLC, 89.3%, RCC, 78.6%; p = 0.47). Prolonged oral RLC and RCC therapy were found to be equally effective in treating patients with BJI caused by resistant GPC, including patients with infected orthopaedic devices. However, the lower cost of cotrimoxazole compared with linezolid renders RCC an attractive treatment alternative to RLC. Further larger clinical studies are warranted to confirm these preliminary results.

Topics: Acetamides; Administration, Oral; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Chronic Disease; Drug Therapy, Combination; Female; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Humans; Linezolid; Male; Middle Aged; Orthotic Devices; Osteomyelitis; Oxazolidinones; Prosthesis-Related Infections; Rifampin; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination; Young Adult

To determine whether the addition of rifampin to a quinolone-based antibacterial prophylactic regimen in patients undergoing high-dose chemotherapy (HDC) with peripheral-blood stem-cell transplantation (PBSCT) decreases the incidence of neutropenia and fever, Gram-positive bacteremia, and infection-related morbidity.. Patients with solid tumors undergoing HDC with PBSCT were randomized to receive prophylactic antibiotics with either ciprofloxacin 500 mg orally every 8 hours or the same ciprofloxacin regimen with rifampin 300 mg orally every 12 hours. Prophylaxis was started 48 hours before stem-cell reinfusion. Patients were monitored to document the occurrence of neutropenia and fever, incidence and cause of bacterial infection, time to onset and duration of fever, requirement for intravenous antimicrobials, and length of hospital admission.. Sixty-five patients were randomized to receive ciprofloxacin and 65 to receive ciprofloxacin plus rifampin, and from these groups, 62 and 61 were assessable, respectively. The proportion of patients who developed neutropenia and fever was 87% in the group treated with ciprofloxacin and 78% in the group treated with ciprofloxacin and rifampin (P =.25). Although there was a trend toward a reduction in the overall incidence of bacteremia (12 v 4 patients), and Gram-positive bacteremia (8 v 2 patients) with the addition of rifampin, none of these comparisons was statistically significant (P =.05 and P =.09, respectively).. The results of this study, which demonstrate that rifampin does not improve ciprofloxacin antibacterial prophylaxis in cancer patients undergoing HDC with PBSCT support but that it does increase the occurrence of undesirable side effects, do not support the routine use of rifampin in this setting.

Topics: Adult; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Antineoplastic Agents; Ciprofloxacin; Drug Therapy, Combination; Female; Fever; Gram-Positive Bacterial Infections; Hematopoietic Stem Cell Transplantation; Humans; Male; Neoplasms; Neutropenia; Prospective Studies; Rifampin; Statistics, Nonparametric; Treatment Outcome

We compared ciprofloxacin alone with ciprofloxacin plus rifampin (C + R) as a prophylactic antibacterial regimen for 40 patients with solid tumors treated with high-dose chemotherapy and autologous stem cell transplantation support. No differences were found between groups in the time elapsed to the onset of fever, incidence of febrile episodes, amphotericin B use, and length of hospital stay. However, C + R combination prophylaxis significantly reduced the incidence of gram-positive bacteremia (five versus zero episodes) but was associated with a higher incidence of drug-related side effects.

Topics: Adult; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotics, Antitubercular; Antineoplastic Combined Chemotherapy Protocols; Ciprofloxacin; Drug Therapy, Combination; Female; Fever; Gram-Positive Bacterial Infections; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Neoplasms; Neutropenia; Rifampin

This study investigated the prevalence and antimicrobial susceptibility of enterococci isolated from dogs and cats with urinary tract infections in northwestern Croatia. During this study, the laboratory received 787 urine samples, 651 from dogs and 136 from cats. A total of 260 urine samples (211 from dogs and 49 from cats) were bacteriologically positive. Of these, 29 isolates belonged to Enterococcus spp.; 22 from dogs and seven from cats. Enterococci isolates were identified by PCR method, 12 of which were Enterococcus faecium and 17 were Enterococcus faecalis species. In dogs, 16 E. faecalis and six E. faecium strains were identified, whereas in cats, six E. faecium and only one E. faecalis strain were identified. Antimicrobial susceptibility was determined by the Kirby-Bauer disk diffusion method for nine antimicrobials: penicillin, ampicillin, vancomycin, nitrofurantoin, rifampicin, tetracycline, chloramphenicol, enrofloxacin, ciprofloxacin. The isolates were tested for high-level resistance to streptomycin and gentamicin. The highest resistance of Enterococcus spp. was observed to rifampicin (86%) and enrofloxacin (83%), followed by tetracycline and ciprofloxacin (69%). Resistance to vancomycin was 28%, and the lowest resistance was to chloramphenicol (17%). Multidrug resistance was found in 76% of enterococci isolates. High-level streptomycin resistance was detected in 17% and high-level gentamicin resistance in 10% of the isolated enterococci. When comparing species susceptibility, E. faecium isolates were significantly more resistant to penicillin, ampicillin, nitrofurantoin, and ciprofloxacin (p < 0.05). Eleven E. faecium isolates (92%) and 12 E. faecalis isolates (76%) were multidrug resistant.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Cat Diseases; Cats; Chloramphenicol; Ciprofloxacin; Croatia; Dog Diseases; Dogs; Drug Resistance, Bacterial; Enrofloxacin; Enterococcus; Enterococcus faecium; Gentamicins; Gram-Positive Bacterial Infections; Microbial Sensitivity Tests; Nitrofurantoin; Penicillins; Prevalence; Rifampin; Streptomycin; Tetracycline; Vancomycin

This study aimed to explore daptomycin combined with fosfomycin or rifampin against the planktonic and adherent linezolid-resistant isolates of Enterococcus faecalis.. Four linezolid-resistant and four linezolid-sensitive isolates of E. faecalis which formed biofilms were collected for this study. Biofilm biomasses were detected by crystal violet staining and the adherent cells in the mature biofilms were quantified by c.f.u. determination.. Daptomycin alone, or combined with fosfomycin or rifampin (4×MIC) demonstrated bactericidal activities on the planktonic cells, and daptomycin combined with fosfomycin killed more planktonic cells (at least 1-log10 c.f.u. ml. Daptomycin combined with fosfomycin demonstrated better effect on the planktonic and adherent linezolid-resistant isolates of E. faecalis than daptomycin or fosfomycin alone. The role of rifampin in the treatment of E. faecalis isolates is discrepant and needs more studies.

Topics: Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Cell Line; Daptomycin; Drug Resistance, Bacterial; Enterococcus faecalis; Fosfomycin; Gram-Positive Bacterial Infections; Humans; Linezolid; Microbial Sensitivity Tests; Plankton; Rifampin

We aimed to describe the effectiveness and safety of the moxifloxacin-rifampicin combination in non-staphylococcal Gram-positive orthopedic implant-related infections.. Patients treated with the moxifloxacin-rifampicin combination for an implant-related infection from November 2014 to November 2016 were retrospectively identified from the database of the referral centers for bone and joint infections in Western France.. Twenty-three cases of infection due to Streptococcus spp. (n=12), Cutibacteriumacnes (n=6), and Enterococcus faecalis (n=5) were included. Ten patients with hip prosthesis were included. Infection was polymicrobial in 11 cases. According to the MIC, moxifloxacin was 1.5 to 11.7 times as active as levofloxacin against non-staphylococcal Gram-positive bacteria. We reported an 81.8% success rate, and no severe adverse effect.. The moxifloxacin-rifampicin combination is a valuable alternative for the treatment of non-staphylococcal Gram-positive implant-related infections because of the good activity of moxifloxacin against these bacteria and the potential activity on the biofilm.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Drug Combinations; Enterococcus faecalis; Female; Gram-Positive Bacterial Infections; Hip Prosthesis; Humans; Male; Middle Aged; Moxifloxacin; Propionibacteriaceae; Prosthesis-Related Infections; Retrospective Studies; Rifampin; Streptococcal Infections; Treatment Outcome

Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI). The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria.. This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012.. Of a total 1066 consecutive patients who had undergone vascular grafts (VG), 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types) received daptomycin (median dose 6.7mg/kg/day, range 4.1-7.1mg/kg/day; median age 69 years, range 45-83 years; 80% male). The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%). The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n=10), Staphylococcus aureus (n=3) (two methicillin-resistant S. aureus), Enterococcus faecium (n=2), and Enterococcus faecalis (n=1). The mean follow-up was 69 months (interquartile range 48-72 months). Ten patients (66.7%) achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured.. The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common.

Topics: Aged; Aged, 80 and over; Anti-Bacterial Agents; Daptomycin; Endocarditis; Enterococcus faecalis; Enterococcus faecium; Female; Follow-Up Studies; Gram-Positive Bacterial Infections; Humans; Male; Methicillin-Resistant Staphylococcus aureus; Middle Aged; Recurrence; Retrospective Studies; Rifampin; Skin Diseases, Infectious; Soft Tissue Infections; Staphylococcus aureus; Treatment Outcome; Vascular Grafting; Wound Healing

Topics: Anti-Bacterial Agents; Drug Therapy, Combination; Eyelid Diseases; Gram-Positive Bacterial Infections; Humans; Immunocompetence; Male; Middle Aged; Rifampin; Skin Diseases, Bacterial; Trimethoprim, Sulfamethoxazole Drug Combination

Enterococci are a leading cause of healthcare-associated infection worldwide and display increasing levels of resistance to many of the commonly used antimicrobials, making treatment of their infections challenging. Combinations of antibiotics are occasionally employed to treat serious infections, allowing for the possibility of synergistic killing. The aim of this study was to evaluate the effects of different antibacterial combinations against enterococcal isolates using an in vitro approach and an in vivo Galleria mellonella infection model. Five Enterococcus faecalis and three Enterococcus faecium strains were screened by paired combinations of rifampicin, tigecycline, linezolid or vancomycin using the chequerboard dilution method. Antibacterial combinations that displayed synergy were selected for in vivo testing using a G. mellonella larvae infection model. Rifampicin was an effective antibacterial enhancer when used in combination with tigecycline or vancomycin, with minimum inhibitory concentrations (MICs) of each individual antibiotic being reduced by between two and four doubling dilutions, generating fractional inhibitory concentration index (FICI) values between 0.31 and 0.5. Synergy observed with the chequerboard screening assays was subsequently observed in vivo using the G. mellonella model, with combination treatment demonstrating superior protection of larvae post-infection in comparison with antibiotic monotherapy. In particular, rifampicin in combination with tigecycline or vancomycin significantly enhanced larvae survival. Addition of rifampicin to anti-enterococcal treatment regimens warrants further investigation and may prove useful in the treatment of enterococcal infections whilst prolonging the clinically useful life of currently active antibiotics.

Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Enterococcus faecalis; Enterococcus faecium; Gram-Positive Bacterial Infections; Lepidoptera; Microbial Sensitivity Tests; Rifampin; Survival Analysis; Treatment Outcome

Currently, Propionibacterium is frequently recognized as a causative microorganism of prosthetic joint infection (PJI). We assessed treatment success at 1- and 2-year follow-up after treatment of Propionibacterium-associated PJI of the shoulder, hip, and knee. Furthermore, we attempted to determine whether postoperative treatment with rifampicin is favorable.. We conducted a retrospective cohort study in which we included patients with a primary or revision joint arthroplasty of the shoulder, hip, or knee who were diagnosed with a Propionibacterium-associated PJI between November 2008 and February 2013 and who had been followed up for at least 1 year.. We identified 60 patients with a Propionibacterium-associated PJI with a median duration of 21 (0.1-49) months until the occurrence of treatment failure. 39 patients received rifampicin combination therapy, with a success rate of 93% (95% CI: 83-97) after 1 year and 86% (CI: 71-93) after 2 years. The success rate was similar in patients who were treated with rifampicin and those who were not.. Propionibacterium-associated PJI treated with surgery in combination with long-term antibiotic administration had a successful outcome at 1- and 2-year follow-up irrespective of whether the patient was treated with rifampicin. Prospective studies are needed to determine whether the use of rifampicin is beneficial in the treatment of Propionibacterium-associated PJI.

Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Cohort Studies; Female; Follow-Up Studies; Gram-Positive Bacterial Infections; Hip Prosthesis; Humans; Kaplan-Meier Estimate; Knee Prosthesis; Male; Middle Aged; Netherlands; Propionibacterium; Prosthesis Failure; Prosthesis-Related Infections; Reference Values; Reoperation; Retrospective Studies; Rifampin; Risk Assessment; Severity of Illness Index; Treatment Outcome

Topics: Female; Gram-Positive Bacterial Infections; Humans; Male; Propionibacterium; Prosthesis-Related Infections; Rifampin

The rapid determination of pathogenic agent is very important to clinician for guiding their clinical medication. However, current diagnostic methods are of limitation in many aspects, such as detecting range, time-consuming, specificity and sensitivity. In this report, we apply our new-developing pathogen detection method to clarify that Propionibacterium acnes is the causative agent of a two-year-old boy with juvenile myelomonocytic leukemia presenting clinical symptoms including serious rash and hyperpyrexia while traditional clinical methods of diagnosis fail to detect the pathogenic agent and multiple antimicrobial drugs are almost ineffective Propionibacterium acnes is confirmed to be the infectious agent by quantitative real-time polymerase chain reaction.. After haploidentical hematopoietic stem cell transplantation, a two-year-old boy with juvenile myelomonocytic leukemia presented to a pediatrist in a medical facility with hyperpyrexia and red skin rash which later changed to black skin rash all over his body. Traditional diagnostic assays were unrevealing, and several routine antimicrobial treatments were ineffective, including the vancomycin, meropenem, tobramycin, cefepime and rifampin. In this case, pediatrist resorted to the next-generation sequencing technology for uncovering potential pathogens so as to direct their use of specific drugs against pathogenic bacteria. Therefore, based on the BGISEQ100 (Ion Proton System) which performed sequencing-by-synthesis, with electrochemical detection of synthesis, and each such reaction coupled to its own sensor, which are in turn organized into a massively parallel sensor array on a complementary metal-oxidesemiconductor chip, we detect and identify the potential pathogens. As a result, we detected a significantly higher abundance of skin bacteria Propionibacterium acnes in patient's blood than controls. It had been reported that patients infected by Propionibacterium acnes almost always had history of immunodeficiency, trauma or surgery. Considering this possible cause, antimicrobial treatment was adjusted to target this rare opportunistic pathogen. Fever and black skin rashes were rapidly reduced after administrating specific drugs against Propionibacterium acnes.. This case showed our new-developing pathogen detection method was a powerful tool in assisting clinical diagnosis and treatment. And it should be paid more attention to Propionibacterium acnes infection in clinical cases.

Topics: DNA, Bacterial; Fever; Gram-Positive Bacterial Infections; Hematopoietic Stem Cell Transplantation; Humans; Male; Postoperative Complications; Propionibacterium acnes; Real-Time Polymerase Chain Reaction; Rifampin; Sequence Analysis, DNA

To study the characteristics of patients with Propionibacterium acnes prosthetic valve endocarditis (PVE) who required surgery.. A single-centre retrospective cohort study was conducted during a 7-year period. Patients with definite infective P. acnes endocarditis, according to the modified Duke criteria, were included. An extended culture protocol was applied. Information on medical health status, surgery, antibiotic treatment and mortality was obtained.. Thirteen patients fulfilled the criteria for P. acnes endocarditis (0.53% of 2466 patients with valve replacement in a 7-year period). All patients were male and had a previous valve replacement. The health status of patients was poor at diagnosis of P. acnes PVE. Most patients (11 of 13, 85%) were admitted with signs of heart failure due to a significant paravalvular leak; 2 of 13 (15%) patients presented with septic emboli. Twelve patients needed redo surgery, whereas one could be treated with antibiotic therapy only. The time between the index surgery and presentation with P. acnes PVE varied between 5 and 135 months (median 26.5 months). Replacement and reconstruction of the dysfunctional valve and affected anatomical structures was mainly performed with a mechanical valve (n = 5, 42%) or a (bio-) Bentall prosthesis (n = 6, 50%). Antibiotic therapy consisted of penicillin with or without rifampicin for 6 weeks after surgery. The mortality in this series was low (n = 1, 8%) and no recurrent endocarditis was found during a median follow-up of 38 months.. Propionibacterium acnes PVE is a rare complication after valve surgery. Redo surgery is often required. Treatment of the dysfunctional prosthetic aortic valve most often consists of root replacement, in combination with antibiotic therapy.

Topics: Adult; Aged; Anti-Bacterial Agents; Communicable Diseases; Endocarditis, Bacterial; Female; Gram-Positive Bacterial Infections; Heart Valve Diseases; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Male; Middle Aged; Propionibacterium acnes; Prosthesis-Related Infections; Retrospective Studies; Rifampin

Topics: Female; Gram-Positive Bacterial Infections; Humans; Male; Propionibacterium; Prosthesis-Related Infections; Rifampin

While individually inefficient against Gram-negative bacteria, in-vitro combinations of rifampin and OAK were mutually synergistic since sub-minimal inhibitory concentrations of one compound have potentiated the other by 2-4 orders of magnitude. Synergy persisted in-vivo as single-dose systemic treatment of Klebsiella infected mice resulted in 10-20% versus 60% survival, respectively accomplished by individual and combined compounds. This outcome was achieved without drug formulation, rather, pharmacokinetic considerations have inspired the therapeutic regimen.

Topics: Animals; Anti-Bacterial Agents; Drug Synergism; Gram-Negative Bacteria; Gram-Positive Bacterial Infections; Klebsiella; Male; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Oligopeptides; Rifampin

Clindamycin, a lincosamide antibiotic with a good penetration into bone, is widely used for treating bone and joint infections by Gram-positive pathogens. To be active against Staphylococcus spp, its concentration at the infection site, C, must be higher than 2× the minimal inhibitory concentration (MIC). The aims of the work were to study the determinants of plasma clindamycin trough concentration, C min, especially the effect of co-treatment with rifampicin, and the consequences on clinical outcome.. An observational study was performed, involving patients hospitalized for a bone and joint infection who received clindamycin as part of their antibiotic treatment. Target C min was 1.7 mg/L, to reach the desired bone concentration/MIC >2, assuming a 30% diffusion into bone and MIC = 2.5 mg/L.. Sixty one patients (mean age: 56.8 years, 57.4% male) were included between 2007 and 2011. 72.1% underwent a surgery on a foreign material, and 91.1% were infected by at least a Gram-positive micro-organism. Median C min value was 1.39 mg/L, with 58% of the values below the threshold value of 1.7 mg/L. Median C min was significantly lower for patients taking rifampicin (0.46 vs 1.52 mg/L, p = 0.034). No patient with rifampicin co-administration reached the target concentration (maximal C min: 0.85 mg/L). After a median follow-up of 17 months (1.5-38 months), 4 patients relapsed, 2 died and 47 (88.7% of the patients with known outcome) were cured, independently of association with rifampicin.. This study shows the high inter-variability of plasma clindamycin concentration and confirms that co-treatment with rifampicin significantly decreases clindamycin trough concentrations.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Clindamycin; Drug Interactions; Drug Therapy, Combination; Female; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Osteomyelitis; Rifampin; Young Adult

Enterococci that are nonsusceptible (NS; MIC > 4 μg/ml) to daptomycin are an emerging clinical concern. The synergistic combination of daptomycin plus beta-lactams has been shown to be effective against vancomycin-resistant Enterococcus (VRE) species in vitro. This study systematically evaluated by in vitro time-kill studies the effect of daptomycin in combination with ampicillin, cefazolin, ceftriaxone, ceftaroline, ertapenem, gentamicin, tigecycline, and rifampin, for a collection of 9 daptomycin-NS enterococci that exhibited a broad range of MICs and different resistance-conferring mutations. We found that ampicillin plus daptomycin yielded the most consistent synergy but did so only for isolates with mutations to the liaFSR system. Daptomycin binding was found to be enhanced by ampicillin in a representative isolate with such mutations but not for an isolate with mutation to the yycFGHIJ system. In contrast, ampicillin enhanced the killing of the LL-37 human antimicrobial peptide against daptomycin-NS E. faecium with either the liaFSR or yycFGHIJ mutation. Antagonism was noted only for rifampin and tigecycline and only for 2 or 3 isolates. These data add support to the growing body of evidence indicating that therapy combining daptomycin and ampicillin may be helpful in eradicating refractory VRE infections.

Topics: Ampicillin; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; beta-Lactams; Cathelicidins; Daptomycin; DNA Mutational Analysis; DNA, Bacterial; Drug Combinations; Drug Interactions; Drug Resistance, Bacterial; Drug Synergism; Enterococcus; Enterococcus faecium; Ertapenem; Gentamicins; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Mutation; Rifampin; Vancomycin Resistance

We described for the first time the amino acid substitutions conferring rifampicin resistance in eight Propionibacterium acnes strains isolated from patients with biofilm or device-related infections. We identified different mutations in cluster I and one mutation, never reported, in cluster II of the rpoB gene (I480V) associated with the most frequent one in cluster I (S442L). Half of the patients previously received treatment with rifampicin.

Topics: Adult; Aged; Aged, 80 and over; Amino Acid Substitution; Anti-Bacterial Agents; Biofilms; Catheter-Related Infections; DNA-Directed RNA Polymerases; Drug Resistance, Bacterial; Female; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Molecular Sequence Data; Mutation, Missense; Propionibacterium acnes; Rifampin; Sequence Analysis, DNA

Topics: Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Cervical Vertebrae; Clindamycin; Drug Therapy, Combination; Embolism; Female; Gram-Positive Bacterial Infections; Headache; Humans; Lemierre Syndrome; Myalgia; Peptostreptococcus; Retropharyngeal Abscess; Rifampin; Spondylitis; Tomography, X-Ray Computed; Young Adult

Topics: Anti-Bacterial Agents; Clindamycin; Female; Gram-Positive Bacterial Infections; Humans; Male; Osteomyelitis; Rifampin

Enterococcal implant-associated infections are difficult to treat because antibiotics generally lack activity against enterococcal biofilms. We investigated fosfomycin, rifampin, and their combinations against planktonic and adherent Enterococcus faecalis (ATCC 19433) in vitro and in a foreign-body infection model. The MIC/MBClog values were 32/>512 μg/ml for fosfomycin, 4/>64 μg/ml for rifampin, 1/2 μg/ml for ampicillin, 2/>256 μg/ml for linezolid, 16/32 μg/ml for gentamicin, 1/>64 μg/ml for vancomycin, and 1/5 μg/ml for daptomycin. In time-kill studies, fosfomycin was bactericidal at 8× and 16× MIC, but regrowth of resistant strains occurred after 24 h. With the exception of gentamicin, no complete inhibition of growth-related heat production was observed with other antimicrobials on early (3 h) or mature (24 h) biofilms. In the animal model, fosfomycin alone or in combination with daptomycin reduced planktonic counts by ≈4 log10 CFU/ml below the levels before treatment. Fosfomycin cleared planktonic bacteria from 74% of cage fluids (i.e., no growth in aspirated fluid) and eradicated biofilm bacteria from 43% of cages (i.e., no growth from removed cages). In combination with gentamicin, fosfomycin cleared 77% and cured 58% of cages; in combination with vancomycin, fosfomycin cleared 33% and cured 18% of cages; in combination with daptomycin, fosfomycin cleared 75% and cured 17% of cages. Rifampin showed no activity on planktonic or adherent E. faecalis, whereas in combination with daptomycin it cured 17% and with fosfomycin it cured 25% of cages. Emergence of fosfomycin resistance was not observed in vivo. In conclusion, fosfomycin showed activity against planktonic and adherent E. faecalis. Its role against enterococcal biofilms should be further investigated, especially in combination with rifampin and/or daptomycin treatment.

Topics: Acetamides; Ampicillin; Animals; Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Calorimetry; Daptomycin; Disease Models, Animal; Drug Therapy, Combination; Enterococcus faecalis; Foreign Bodies; Fosfomycin; Gentamicins; Gram-Positive Bacterial Infections; Guinea Pigs; Linezolid; Male; Microbial Sensitivity Tests; Oxazolidinones; Rifampin; Vancomycin

Endocarditis due to Propionibacterium acnes is a rare disease. Scant data on treatment of these infections is available and is based on case reports only. If the disease is complicated by abscess formation, surgical intervention combined with an antibiotic therapy might improve clinical outcome. In some cases, cardiac surgeons are reluctant to perform surgery, since they consider the intervention as high risk. Therefore, a conservative therapy is required, with little, if any evidence to choose the optimal antibiotic. We report the first case of a successfully treated patient with P. acnes prosthetic valve endocarditis without surgery.. We report the case of a 29-year-old patient with a prosthetic valve endocarditis and composite graft infection with abscess formation of the left ventricular outflow tract due to P. acnes. Since cardiac surgery was considered as high risk, the patient was treated intravenously with ceftriaxone 2 g qd and rifampin 600 mg bid for 7 weeks and was switched to an oral therapy with levofloxacin 500 mg bid and rifampin 600 mg bid for an additional 6 months. Two sets of blood cultures collected six weeks after completion of treatment remained negative. The patient is considered to be cured based on absence of clinical signs and symptoms, normal laboratory parameters, negative radiology scans and negative blood cultures, determined at site visits over two years after completion of treatment.. To our knowledge, this is the first successfully managed patient with P. acnes prosthetic valve endocarditis with abscess formation of the left ventricular outflow tract who was treated with antibiotics alone without a surgical intervention. A six month treatment with a rifampin and levofloxacin combination was chosen, based on the excellent activity against stationary-phase and adherent bacteria.

Topics: Abscess; Adult; Anti-Bacterial Agents; Ceftriaxone; Communicable Diseases; Endocarditis, Bacterial; Gram-Positive Bacterial Infections; Heart Valve Prosthesis; Humans; Levofloxacin; Male; Middle Aged; Propionibacterium acnes; Prosthesis-Related Infections; Rifampin; Treatment Outcome

This paper presents a rare case of facial soft tissue infection caused by the bacterial strain of Rothia mucilaginosa. Odontogenic background of infection and initial clinical presentation suggested the presence of typical bacterial flora and uncomplicated course of treatment. However, despite surgical intervention and broad-spectrum antibiotic therapy, the expected improvement of a clinical status was not achieved. Only detailed bacteriological examination allowed to establish a bacterial pathogen and start a targeted antibiotic therapy. The unusual clinical course was monitored by imaging CT examination and further surgical interventions. A significant improvement was obtained in the third week of hospitalization and further antibiotic therapy was continued by means of outpatient treatment. Rothia mucilaginosa infection together with dental intervention is a rare case, since most of the reports in the literature concern the patients with decreased immunity. In such patients, the most common areas of infection were: the peritoneum, lung tissue and meningeal spaces of the brain and the presence of a foreign body. 

Topics: Abscess; Adult; Anti-Bacterial Agents; Cheek; Drug Administration Schedule; Female; Gram-Positive Bacterial Infections; Humans; Micrococcus; Rifampin; Soft Tissue Infections; Tooth Extraction; Toothache; Trismus; Young Adult

Sinus lift is a predictable procedure for increasing alveolar bone height in the posterosuperior alveolar regions to allow oral prosthetic rehabilitation. Several complications have been documented in the literature and vary from sinus membrane perforation to maxillary rhinosinusitis. The authors present a case of Gemella morbillorum acute sinusitis after sinus lift surgery. The purpose of this report is to describe the surgical and pharmacological management of a patient allergic to penicillin.

Topics: Anti-Bacterial Agents; Bone Transplantation; Drug Hypersensitivity; Endoscopy; Female; Follow-Up Studies; Gemella; Gram-Positive Bacterial Infections; Humans; Levofloxacin; Maxillary Sinusitis; Middle Aged; Penicillins; Reoperation; Rifampin; Sinus Floor Augmentation; Surgical Wound Infection; Vancomycin

Topics: Anti-Bacterial Agents; Daptomycin; Female; Gram-Positive Bacterial Infections; Humans; Male; Prosthesis-Related Infections; Rifampin

Topics: Anti-Bacterial Agents; Daptomycin; Female; Gram-Positive Bacterial Infections; Humans; Male; Prosthesis-Related Infections; Rifampin

Topics: Aged; Animals; Anti-Bacterial Agents; Bacteremia; Braces; Cattle; Combined Modality Therapy; Discitis; Drug Therapy, Combination; Endocarditis, Bacterial; Female; Food Contamination; Gentamicins; Gram-Positive Bacterial Infections; Humans; Lactococcus; Lumbar Vertebrae; Milk; Ofloxacin; Pasteurization; Rifampin

We investigated the efficacy of tigecycline and rifampin alone or combined in preventing ureteral stent infection due to Enterococcus faecalis.. The activities of the two antibiotics were previously studied in vitro in absence or in presence of biofilm. For in vivo research, the study included a control group without bacterial challenge to evaluate the sterility of surgical procedure, a challenged control group that did not receive any antibiotic prophylaxis and, for each bacterial strain, three challenged groups that received: (1) 2 mg/kg intraperitoneal tigecycline, immediately after stent implantation; (2) rifampin-coated ureteral stents where 0.2 cm(2) sterile ureteral stents were incubated in 10 mg/L rifampin solution for 30 min immediately before implantation; and (3) intraperitoneal tigecycline plus rifampin-coated ureteral stent at the above concentrations. Ureteral stents were explanted at d 5 following implantation and biofilm bacteria enumerated.. The in vitro studies showed that the biofilm was strongly affected by the presence of rifampin and, in its presence, tigecycline had MICs and MBCs lower than those obtained in the absence of rifampin. Intraperitoneal tigecycline exerted stronger effect than rifampin on bacterial numbers. The combination rifampin plus tigecycline showed efficacies higher than that of each single compound.. These results highlight the potential usefulness of tigecycline in preventing enterococcal ureteral stent infections and the role of rifampin as an interesting antibiotic enhancer.

Topics: Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Biofilms; Disease Models, Animal; Drug Therapy, Combination; Enterococcus faecalis; Female; Gram-Positive Bacterial Infections; In Vitro Techniques; Minocycline; Rats; Rats, Wistar; Rifampin; Stents; Tigecycline; Treatment Outcome; Ureter

The objective of this report is to discuss the efficacy of in situ replacement for treating mycotic aneurysm, particularly using rifampicin-bonded grafts and omental pedicle grafts, on the basis of our 7 years of experience.. Between December 2003 and December 2010, we performed surgical treatments in 23 patients (for the thoracic aorta in 6 patients, for the thoracoabdominal aorta in 8 patients, and for the abdominal aorta in 9 patients; 7 emergency, 10 urgent, and 6 elective operations) with mycotic aneurysm by using rifampicin-bonded grafting and omental pedicle grafting.. One patient died in hospital because of local recurrent infection. One patient required an additional operation on another aortic site, and 3 patients had spinal cord injuries (2 transient and 1 permanent). Overall survival at 5 years was 95%, and the rate of freedom from aortic events at 5 years was 86%.. In situ replacement using rifampicin-bonded grafting and omental pedicle grafting is effective for treating mycotic aneurysms of the thoracic and abdominal aorta.

Topics: Aged; Aged, 80 and over; Aneurysm, Infected; Anti-Bacterial Agents; Aortic Aneurysm, Abdominal; Aortic Aneurysm, Thoracic; Bacteremia; Blood Vessel Prosthesis Implantation; Combined Modality Therapy; Elective Surgical Procedures; Enterobacteriaceae Infections; Female; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Omentum; Polyethylene Terephthalates; Retrospective Studies; Rifampin; Stents; Surgical Flaps; Treatment Outcome

The aim of this work was to determine the in vitro activity of tigecycline and its bactericidal effect for a large number of Gram-positive cocci, as well as to investigate its in vitro interaction with six clinically used antibiotics. In vivo, a wound model was established through the panniculus carnosus of BALB/c mice, and then inoculated with 5 × 10(7) colony-forming units (CFU) of Staphylococcus aureus or Enterococcus faecalis. For each bacterial strain, the study included an infected or non-infected group that did not receive any treatment, three groups singly treated with tigecycline, rifampin, and daptomycin, and two groups that received tigecycline treatment plus rifampin or daptomycin. In the in vitro studies, tigecycline, daptomycin, and teicoplanin were active against all of the 48 Gram-positive isolates. The combination of tigecycline with rifampicin and daptomycin was synergistic against S. aureus and Enterococcus spp. In the in vivo studies, all groups treated with single drugs showed statistically significant results compared to the control group. The two groups treated with a combination of drugs showed the highest antimicrobial efficacy. In conclusion, our results suggested a strong activity of tigecycline alone and in combination with other antimicrobial agents against multi-resistant Gram-positive organisms isolated from wound infections.

Topics: Animals; Anti-Bacterial Agents; Daptomycin; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Male; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Minocycline; Rifampin; Surgical Wound Infection; Tigecycline; Treatment Outcome

Propionibacterium acnes is an important cause of orthopedic-implant-associated infections, for which the optimal treatment has not yet been determined. We investigated the activity of rifampin, alone and in combination, against planktonic and biofilm P. acnes in vitro and in a foreign-body infection model. The MIC and the minimal bactericidal concentration (MBC) were 0.007 and 4 μg/ml for rifampin, 1 and 4 μg/ml for daptomycin, 1 and 8 μg/ml for vancomycin, 1 and 2 μg/ml for levofloxacin, 0.03 and 16 μg/ml for penicillin G, 0.125 and 512 μg/ml for clindamycin, and 0.25 and 32 μg/ml for ceftriaxone. The P. acnes minimal biofilm eradication concentration (MBEC) was 16 μg/ml for rifampin; 32 μg/ml for penicillin G; 64 μg/ml for daptomycin and ceftriaxone; and ≥128 μg/ml for levofloxacin, vancomycin, and clindamycin. In the animal model, implants were infected by injection of 10⁹ CFU P. acnes in cages. Antimicrobial activity on P. acnes was investigated in the cage fluid (planktonic form) and on explanted cages (biofilm form). The cure rates were 4% for daptomycin, 17% for vancomycin, 0% for levofloxacin, and 36% for rifampin. Rifampin cured 63% of the infected cages in combination with daptomycin, 46% with vancomycin, and 25% with levofloxacin. While all tested antimicrobials showed good activity against planktonic P. acnes, for eradication of biofilms, rifampin was needed. In combination with rifampin, daptomycin showed higher cure rates than with vancomycin in this foreign-body infection model.

Topics: Animals; Anti-Bacterial Agents; Biofilms; Calorimetry; Foreign Bodies; Gram-Positive Bacterial Infections; Guinea Pigs; Male; Microbial Sensitivity Tests; Propionibacterium acnes; Rifampin

Topics: Animals; Anti-Bacterial Agents; Drug Therapy, Combination; Echocardiography, Transesophageal; Endocarditis, Bacterial; Fisheries; Gentamicins; Gram-Positive Bacterial Infections; Heart Valve Prosthesis; Humans; Lactococcus; Male; Middle Aged; Rifampin; Vancomycin; Zoonoses

The dynamics of isolation of staphylococci and enterococci from clinical material of patients and their antibiotic susceptibility within a 5-year period (2005-2009) was analysed. 5990 isolates were tested: 1250 isolates of Staphylococcus aureus, 3268 isolates of S. epidermidis, 1005 isolates of Enterococcus faecalis and 467 isolates of E. faecium. Grampositive infections were shown to be prevailing within the last 2-3 years, the nosocomial epidermal staphylococci more and more replacing S. aureus (the ratio of S. epidermidis and S. aureus in 2009 was 3.3). The isolation rate of E. faecalis significantly increased (by 3.5 times) and the ratio of E. faecalis and E. faecium in 2009 was 4.3. The microflora composition with respect to the isolation source was analysed and its clinical significance was estimated. The study of the antibiotic susceptibility showed that oxacillin had its own specific niche, while antibiotics active against resistant grampositive cocci, such as rifampicin, fusidic acid, fluoroquinolones (moxifloxacin), cefoxitin, as well as amoxicillin/clavulane in infections due to E. faecalis, might be considered as the drugs of choice. In the treatment of nosocomial infections, when the etiological role of MRSA or VRE is suspected or confirmed, the complex therapy should obligatory include the most active antibiotics (vancomycin or linezolid among them).

Topics: Acetamides; Amoxicillin; Anti-Bacterial Agents; Cefoxitin; Cross Infection; Drug Resistance, Microbial; Enterococcus; Fluoroquinolones; Fusidic Acid; Gram-Positive Bacterial Infections; Humans; Linezolid; Methicillin-Resistant Staphylococcus aureus; Moscow; Oxacillin; Oxazolidinones; Rifampin; Surgery, Plastic; Vancomycin

The purpose of this study was to assess the clinical efficacy of high-dose levofloxacin plus rifampicin in the empirical treatment of non-tuberculous spondylodiscitis in an epidemiological context of low incidence of staphylococcal fluoroquinolone resistance. All consecutive adult patients with spondylodiscitis (January 2003 to December 2006) were empirically treated with high-dose levofloxacin (500 mg every 12 h normalised to renal function and optimised by means of therapeutic drug monitoring whenever feasible) plus rifampicin 600 mg every 24 h. Trough and peak plasma concentrations were targeted at 1-3 mg/L and 6-9 mg/L, respectively, to maximise the concentration-dependent activity of levofloxacin in bone. Follow-up was performed until 9 months after the end of therapy. Forty-eight patients were included. Eleven patients underwent a surgical approach for spine stabilisation. Among the 29 bacterial isolates, Staphylococcus aureus was the most frequent (65.5%) (all meticillin-susceptible strains). Tailored levofloxacin plasma exposure over time was ensured in most cases. Median treatment duration was 15.1 weeks. Overall response rates were: 77.1% at the intent-to-treat analysis; 84.1% among patients who completed therapy (N=44); and 96.3% among those receiving targeted therapy against documented levofloxacin-susceptible isolates (N=27). No patient had evidence of disease relapse at follow-up. Our findings suggest that high-dose levofloxacin regimens may be highly effective in the treatment of non-tuberculous spondylodiscitis and support its putative role in combination with rifampicin against S. aureus.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Discitis; Drug Monitoring; Female; Follow-Up Studies; Gram-Positive Bacterial Infections; Humans; Levofloxacin; Male; Middle Aged; Ofloxacin; Rifampin; Treatment Outcome; Young Adult

Topics: Abscess; Aged; Amoxicillin; Anti-Bacterial Agents; Aortic Valve; Bacteremia; Combined Modality Therapy; Device Removal; Endocarditis, Bacterial; Gentamicins; Gram-Positive Bacterial Infections; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Male; Pacemaker, Artificial; Propionibacterium acnes; Prosthesis-Related Infections; Reoperation; Rifampin

We assessed the in vitro effect of exposing various bacteria to minocycline/rifampicin-impregnated vascular catheters on the antimicrobial activity of the catheters and the antimicrobial susceptibility of tested organisms.. Segments of minocycline/rifampicin-impregnated catheters were placed in agar plates inoculated with methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and vancomycin-resistant Enterococcus (VRE). Zones of inhibition were measured at 24 h, and colonies from the edge of this zone were retrieved after 72 h and inoculated onto new agar plates. A total of seven 72 h cycles were completed. We then measured the MICs of minocycline, rifampicin, vancomycin and linezolid for the collected strains.. The zones of inhibition of the four organisms remained stable after 21 days of sequential exposure to the impregnated catheters. The MICs of the antimicrobials remained constant, except for the MICs of rifampicin for MRSA and linezolid for MRSE, which increased slightly but remained within the susceptible range.. Minocycline/rifampicin-impregnated catheters remain effective against MSSA, MRSA, MRSE and VRE, as evidenced by stable zones of inhibition following 21 day sequential exposure to these catheters. The increase in MIC of rifampicin for MRSA may be clinically relevant if the catheter remains in place for >12 days though the strain remained susceptible to minocycline, there was no concurrent increase in the MIC of other tested drugs, and the zones of inhibition remained stable.

Topics: Anti-Bacterial Agents; Bacteremia; Catheterization, Central Venous; Drug Resistance, Bacterial; Equipment Contamination; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Humans; Microbial Sensitivity Tests; Minocycline; Rifampin; Time Factors

Topics: Anti-Bacterial Agents; Bacteremia; Child, Preschool; Exocrine Pancreatic Insufficiency; Gram-Positive Bacterial Infections; Humans; Male; Microbial Sensitivity Tests; Micrococcaceae; Osteochondrodysplasias; Rifampin; Syndrome

Topics: Adult; Arthroplasty, Replacement, Hip; Bacteremia; Cefotaxime; Device Removal; Drug Therapy, Combination; Focal Infection, Dental; Gram-Positive Bacterial Infections; Hip Prosthesis; Humans; Legg-Calve-Perthes Disease; Male; Penicillin G; Prosthesis-Related Infections; Reoperation; Rifampin; Staphylococcaceae; Teicoplanin

Propionibacterium acnes is increasingly recognized as a cause of delayed infection after spinal instrumentation or shunting for hydrocephalus. Biofilm development by this organism has recently been demonstrated. We therefore investigated the effect of two different courses of three antibiotics (penicillin, rifampicin and linezolid) on mature P. acnes biofilms in vitro. Outcomes were eradication or regrowth after withdrawal of antibiotics, simulating successful treatment and relapse.. P. acnes biofilms were grown on titanium discs for 6 days until mature, then exposed to the antibiotics for either 7 or 14 days before sonication and culture. Further, discs were similarly exposed, but after each course, they were reincubated for a further 9 days to check for regrowth.. Penicillin, linezolid and linezolid plus rifampicin eradicated P. acnes biofilms after 14 days, but only penicillin had this effect after 7 days. 'Relapse' was prevented only by 14 day courses of penicillin or linezolid plus rifampicin, but not by linezolid alone.. For P. acnes spinal instrumentation infections, either penicillin or linezolid plus rifampicin might be equally effective. For shunt infections, as penicillin does not give therapeutic cerebrospinal fluid concentrations, rifampicin plus linezolid might be the treatment of choice. Linezolid alone appears not to be as effective as penicillin against P. acnes biofilms.

Topics: Acetamides; Anti-Bacterial Agents; Biofilms; Cerebrospinal Fluid Shunts; Colony Count, Microbial; Gram-Positive Bacterial Infections; Humans; Hydrocephalus; Linezolid; Microbial Sensitivity Tests; Oxazolidinones; Penicillin G; Propionibacterium acnes; Rifampin; Surgical Wound Infection; Titanium

We report the case of a 36-year-old patient who experienced an isolated acute pulmonary homograft endocarditis two years after a Ross procedure for aortic valve infective endocarditis.

Topics: Adult; Ampicillin; Aortic Valve; Bioprosthesis; Combined Modality Therapy; Drug Therapy, Combination; Endocarditis, Bacterial; Enterococcus faecalis; Gentamicins; Gram-Positive Bacterial Infections; Heart Valve Prosthesis; Hepatitis C, Chronic; HIV Infections; Humans; Male; Methadone; Prosthesis-Related Infections; Pulmonary Valve; Rifampin; Substance Abuse, Intravenous; Transplantation, Autologous

Topics: Anti-Bacterial Agents; Aza Compounds; Bone Diseases, Infectious; Drug Therapy, Combination; Fluoroquinolones; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Humans; Joint Diseases; Microbial Sensitivity Tests; Moxifloxacin; Quinolines; Rifampin

Topics: Anti-Bacterial Agents; Cefotaxime; Child, Preschool; Gram-Positive Bacterial Infections; Humans; Male; Meningitis, Bacterial; Micrococcaceae; Neutropenia; Rifampin; Vancomycin

A nested reverse transcriptase (RT) PCR assay detected mRNA of the salmonid pathogen Renibacterium salmoninarum in samples of RNA extracts of between 1 and 10 cells. Total RNA was extracted from cultured bacteria, Atlantic salmon (Salmo salar L.) kidney tissue and ovarian fluid seeded with the pathogen, and kidney tissue from both experimentally challenged and commercially raised fish. Following DNase treatment, extracted RNA was amplified by both RT PCR and PCR by using primers specific for the gene encoding the major protein antigen of R. salmoninarum. A 349-bp amplicon was detected by polyacrylamide gel electrophoresis and silver stain. Inactivation of cultured bacteria by rifampin or erythromycin produced a loss of nested RT PCR mRNA detection corresponding to a loss of bacterial cell viability determined from plate counts but no loss of DNA detection by PCR. In subclinically diseased fish, nested RT PCR identified similar levels of infected fish as determined by viable pathogen culture. Higher percentages of fish testing positive were generated by PCR, particularly in samples from fish previously subjected to antibiotic chemotherapy where 93% were PCR positive, but only 7% were nested RT PCR and culture positive. PCR can generate false-positive data from amplification of target DNA from nonviable pathogen cells. Therefore, nested RT PCR may prove useful for monitoring cultured Atlantic salmon for the presence of viable R. salmoninarum within a useful time frame, particularly samples from broodstock where antibiotic chemotherapy is used prior to spawning to reduce vertical pathogen transmission.

Topics: Animals; Anti-Bacterial Agents; Culture Media; DNA, Bacterial; Erythromycin; Female; Fish Diseases; Gram-Positive Bacterial Infections; Kidney; Micrococcaceae; Ovary; Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Bacterial; RNA, Messenger; Salmo salar; Sensitivity and Specificity

Twenty-eight phenotypically separate strains of clinically isolated vancomycin-resistant enterococci have been investigated with two API identification kit systems (20 Strep and Rapid ID 32 Strep) and two BBL Crystal kits (Gram Positive and Rapid Gram Positive). All strains were identified as Enterococcus faecium by a reference laboratory. The Rapid ID 32 kit positively identified 15 of 28 strains (54%), but only two (7%) were identified correctly: 11 were identified as 'doubtful' or 'to genus level' and two gave 'unacceptable' profiles. The API 20 Strep kit identified 27 strains (96%), but only 16 (57%) were identified correctly as E. faecium. The Rapid ID 32 kit erred by either positively misidentifying vancomycin-resistant E. faecium as E. casseliflavus or E. gallinarum, or indicated that this was the most likely identification, while the API 20 Strep kit more commonly produced a misidentification as E. casseliflavus. The Crystal Gram Positive and Rapid Gram Positive kits correctly identified 26 (93%) and 27 (96%) of the strains, respectively.

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Drug Resistance, Microbial; Enterococcus faecium; Gentamicins; Gram-Positive Bacterial Infections; Humans; Reagent Kits, Diagnostic; Rifampin; Streptomycin; Vancomycin

The in vitro bactericidal interaction of trovafloxacin and rifampin against Enterococcus spp. has indicated that antagonism occurs between these two antimicrobial agents. This drug combination was examined in vivo in rats with experimental pyelonephritis. The rats received trovafloxacin, rifampin, or both drugs. On the basis of the mean log10 CFU of Enterococcus faecalis from the kidneys, there was no evidence that trovafloxacin and rifampin were antagonistic in vivo.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Drug Interactions; Drug Therapy, Combination; Enterococcus faecalis; Female; Fluoroquinolones; Gram-Positive Bacterial Infections; Naphthyridines; Pyelonephritis; Rats; Rats, Sprague-Dawley; Rifampin

Topics: Aged; Doxycycline; Drug Resistance, Microbial; Drug Synergism; Drug Therapy, Combination; Endocarditis, Bacterial; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Male; Rifampin; Vancomycin; Virginiamycin

Prostatitis due to vancomycin-resistant enterococci has not been previously described. Reported here is a case of chronic prostatitis due to Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin and doxycycline, in a 42-year-old liver transplant recipient. Treatment with a combination of rifampin and nitrofurantoin for 6 weeks resulted in long-lasting cure. Other antimicrobial agents active in vitro against vancomycin-resistant enterococci, such as quinupristin/ dalfopristin and chloramphenicol, are unlikely to achieve sufficient prostatic tissue levels to be successfully utilized for treatment of this condition.

Topics: Adult; Anti-Bacterial Agents; Anti-Infective Agents, Urinary; Chronic Disease; Drug Resistance, Microbial; Drug Resistance, Multiple; Drug Therapy, Combination; Enterococcus faecium; Gram-Positive Bacterial Infections; Humans; Liver Transplantation; Male; Nitrofurantoin; Prostatitis; Rifampin; Urine; Vancomycin

We compared ciprofloxacin, rifampin, and gentamicin treatments, alone and in combination, for 5 days in the therapy of experimental aortic valve endocarditis in rats caused by a clinical isolate of vancomycin-resistant Enterococcus faecium. The MICs and MBCs of vancomycin, ciprofloxacin, rifampin, and gentamicin were 250 and > 1,000, 3.1 and 6.3, 0.098 and 1.6, and 12.5 and > 50 micrograms/ml, respectively. Infected rats were sacrificed after completing 5 days of therapy. Additional rats within each treatment group were followed for 5 days beyond the last dose of antibiotic therapy. Although survivals in the different groups were not significantly different after 5 days of therapy, survival was significantly better 5 days beyond the last dose of antibiotic therapy in rats treated with rifampin-containing regimens. The combination of ciprofloxacin and gentamicin was bactericidal in vitro and in vegetations from rats with enterococcal endocarditis. Rifampin alone was similarly bactericidal in vivo, but it was not significantly better than rifampin in combination with other antibiotics. Subpopulations resistant to rifampin, but not ciprofloxacin, were detected in the inoculum and in most vegetations during therapy. However, the combination of ciprofloxacin plus both gentamicin and rifampin reduced both the rifampin-susceptible and -resistant population in vegetations of 9 of 10 animals below the level of detection after 5 days of therapy. Nevertheless, a residual enterococcal population apparently remained in numbers of < 2 log10 CFU/g after 5 days of therapy, which resulted in relapse. Perhaps a longer course of therapy would have eliminated this residual population and improved efficacy.

Topics: Ampicillin Resistance; Animals; Ciprofloxacin; Disease Models, Animal; Drug Resistance, Microbial; Drug Therapy, Combination; Endocarditis, Bacterial; Enterococcus faecalis; Gentamicins; Gram-Positive Bacterial Infections; Male; Microbial Sensitivity Tests; Rats; Rats, Sprague-Dawley; Rifampin; Vancomycin

Topics: Dose-Response Relationship, Drug; Drug Evaluation; Drug Resistance, Microbial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Rifampin