clove and Staphylococcal-Infections

The leaves of Rhodomyrtus tomentosa are traditionally used in the treatment of infectious diseases such as wound infections in Chinese traditional medicine. The mechanisms of the activity of rhodomyrtosone B (RDSB), a natural acylphloroglucinol isolated from the leaves of Rhodomyrtus tomentosa, are still not understood. We provided a detailed investigation of the antibacterial action of RDSB against bacteria in vitro and in vivo.. The antibacterial activity of RDSB was tested by the microdilution method against a panel of bacteria, and a time-killing assay was carried out according to CLSI guidelines. The cytotoxic potential of RDSB was evaluated against mammalian cells, and its haemolytic activity towards rabbit red blood cells (RBCs) was assessed. The mode of action of RDSB was investigated by targeting bacterial membranes, and its resistance was evaluated using a sequential passaging method. The antibacterial activities in vivo were assessed against MRSA in a mouse skin infection mode.. RDSB has profound antibacterial activity against drug-resistant bacteria (MRSA and VRE) and low cytotoxicity. It is bactericidal in nature, and an increase in membrane permeability resulting from membrane perturbation is one of its modes of action. RDSB represents a promising natural antibiotic to combat drug-resistant (MRSA and VRE) infections.

Topics: Animals; Anti-Bacterial Agents; Cell Line; Erythrocytes; Female; Heterocyclic Compounds, 3-Ring; Methicillin-Resistant Staphylococcus aureus; Mice, Inbred BALB C; Microbial Sensitivity Tests; Myrtaceae; Phytotherapy; Rabbits; Staphylococcal Infections

Staphylococcus aureus is one of the major microorganisms that cause human diseases, leading from mild skin infections to serious diseases. With the use of semi-synthetic penicillins, methicillin-resistant strains called Methicillin-resistant Staphylococcus aureus (MRSA) have emerged, whose resistance pattern extends to other beta-lactam antibiotics. It has already been shown that photodynamic therapy is capable of inactivating MRSA as the laser excites the photosensitizer responsible for transferring its electrons to the molecular oxygen, generating extremely reactive molecules, such as singlet oxygen, being these reactive components the chemicals that promote the bacterial clearance. Thus, the research aiming at the development of new photosensitizers becomes important, especially to increase the amount of therapeutic resources available for the treatment of persistent infections related to this bacterium. In this context, Myrciaria cauliflora is a plant that has antimicrobial action and there are no reports of the use of its crude extract as a photosensitizer in antimicrobial photodynamic therapy. In that way, this work conveys an innovative way of the use of M. cauliflora extract as a photosensitizer, comprising its use as an antimicrobial agent when activated by light, against S. aureus. In vitro tests were performed where it was observed that after the photoactivation with blue LED light, the extract presented an augment in its antimicrobial activity, together with production of singlet oxygen. In the model of intradermal infection in Balb/c mice, a reduction in bacterial load was also detected, with raised expression of TNF-α, IL-17A, and MPO. Here, we demonstrate that the extract of M. cauliflora has photosensitizing action, promoting the production of singlet oxygen, besides IL-17A, TNF-α, and MPO.

Topics: Animals; Anti-Bacterial Agents; Bacterial Load; Cytokines; Humans; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred BALB C; Myrtaceae; Photochemotherapy; Photosensitizing Agents; Pilot Projects; Plant Extracts; Singlet Oxygen; Staphylococcal Infections

An ethanolic extract from Rhodomyrtus tomentosa leaves (RTL) was studied as a natural alternative to control Staphylococcus aureus, which is an important pathogen responsible for bovine mastitis. The minimal inhibitory concentrations (MICs) of the RTL extract and of rhodomyrtone, a pure compound isolated from the plant, were determined by a microdilution method. Rhodomyrtone and the RTL extract exhibited antibacterial activity against S. aureus, including its persistent phenotype (SCV: small-colony variant) and a biofilm hyperproducer strain, with MICs of 0.25-0.5 and 8-16 µg/mL, respectively. Time-kill kinetics showed a strong bactericidal activity for both the RTL extract- and rhodomyrtone-treated bacteria at 2 × MIC as early as 4 h post-exposure. An additive effect of the extract at 0.5 × MIC was observed in a combination with oxytetracycline or pirlimycin against S. aureus by showing a 64- to 128-fold reduction in antibiotic MICs. Moreover, the RTL extract significantly decreased the number of intracellular SCVs inside bovine mammary epithelial cells. However, the extract or its combination with pirlimycin only slightly improved the activity of pirlimycin against the bacterial colonization of mouse mammary glands. In vitro MICs determined in the presence of casein indicated that the limited activity of the RTL extract in the murine model of mastitis could be linked to neutralization of active components by milk proteins. While the RTL extract showed interesting antibacterial properties in vitro, to be considered as an alternative to antibiotics in dairy farms, formulation studies are needed to cope with the observed reduction of activity in vivo.

Topics: Animals; Anti-Bacterial Agents; Cattle; Disease Models, Animal; Epithelial Cells; Female; Mastitis, Bovine; Mice; Microbial Sensitivity Tests; Myrtaceae; Plant Extracts; Staphylococcal Infections; Staphylococcus aureus; Xanthones

Methicillin-resistant Staphylococcus aureus (MRSA) has an ability to invade nonprofessional phagocytic cells, resulting in persistent infections and most likely host cell death. Series of our studies have claimed pronounced antibacterial efficacy of Rhodomyrtus tomentosa leaf extract. This study was to further investigate potency of the extract in intracellular killing of human HaCaT keratinocytes. Pretreatment of MRSA with the extract resulted in a remarkable reduction in the bacterial adhesion to HaCaT keratinocytes, compared with untreated control (p < 0.001). In addition, at least 60% inhibition of the bacterial invasion into HaCaT cells was observed. Intracellular killing assay demonstrated that the extract exhibited strong antibacterial activity against intracellular MRSA at nontoxic concentrations (128 mg/L), which may have resulted from the increase in bactericidal activity under phagolysosomal pH. Transmission electron microscopy displayed the effects of the extract on alterations in the bacterial cell morphology with cell lysis. Fluorescence microscopy revealed that the extract decreased MRSA-induced apoptosis in HaCaT cells. In addition, cytotoxicity of HaCaT cells caused by MRSA supernatant was reduced at least 50% by the extract. The potential activities of R. tomentosa extract may be useful in an alternative treatment of MRSA infections in slight acidic compartments, particularly skin infections.

Topics: Anti-Bacterial Agents; Bacterial Adhesion; Cells, Cultured; Humans; Keratinocytes; Methicillin; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Myrtaceae; Plant Extracts; Plant Leaves; Staphylococcal Infections

Kitoza is a traditional meat product from Madagascar manufactured with strips of pork or beef. The process includes a first step of salting and mixing with spices followed by sun-drying or smoking step. As salting and drying select coagulase-negative staphylococci (CNS), our aim was to identify the CNS species in kitoza with the objective in the future of developing indigenous starters. Microbial analyses revealed that the only pathogenic bacterium enumerated was Staphylococcus aureus, which was found in 54% of the samples. The level of Enterobacteriaceae revealed a rather good hygienic quality of these products. CNS were confirmed in all the samples at high levels ranging from 5 to 7logcfu/g. Identification of CNS species in a large collection of 829 isolates revealed 9 identified species, 7 for beef and 8 for pork kitoza. There were significant difference in the distribution of CNS species according to the type of meat and the process. Staphylococcus saprophyticus was the dominant species for sun-dried or smoked beef and sun-dried pork kitoza (73-75%), while for smoked pork kitoza Staphylococcus equorum (26%), S. saprophyticus (23%), Staphylococcus succinus (23%) and Staphylococcus epidermidis (17%) co-dominated. Some CNS could be used as indigenous starters in particular to compete against S. aureus.

Topics: Animals; Biodiversity; Cattle; Ecosystem; Food Microbiology; Food Preservation; Genetic Variation; Hydrogen-Ion Concentration; Madagascar; Meat Products; Red Meat; Sodium Chloride; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus; Swine; Temperature

The laboratory of Training and Research in Medical Biology of Madagascar conducted a cross-sectional study to estimate the rate of S. aureus nasal carriage of pig and poultry Malagasy farmers.. Pig and poultry farmers from capital town of Madagascar were selected for nasal swabs collection with information on potential risk factors for S. aureus colonization, including animal exposure.. Nasal swabs from 180 farmers (M/F sex ratio: 0.74), enabled isolation after culture and biochemical identification, 69 (38.33%) S. aureus strains among which 45 (25%) were methicillin-resistant (MRSA). Risk factors analysis revealed that farming duration, number of animals, direct contact with poultry, and frequent contact with manure increased risk of S. aureus and MRSA nasal carriage. Likewise, farm practices that imply close contact with pigs such as food distribution and pigsty washing increased risk of S. aureus and MRSA nasal carriage among pig farmers. Among MRSA isolates, resistance rate to other antibiotics was similar to that of MRSA isolates from the non-farmer Malagasy population. However, gentamycin resistance was noticeably higher (32.5% versus 4.44%).. This study shows a high rate of S. aureus and MRSA nasal carriage with high rate of multidrug resistance among healthy people frequently in contact with animals. A strategic policy against the spread of multidrug-resistant strains is desirable in farms and veterinary areas.

Topics: Adult; Animal Husbandry; Animals; Carrier State; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Farmers; Female; Humans; Madagascar; Male; Methicillin-Resistant Staphylococcus aureus; Occupational Exposure; Poultry; Prevalence; Staphylococcal Infections; Swine; Young Adult

Methicillin-resistant Staphylococcus aureus (MRSA) clones pose a significant threat to hospitalised patients because the bacteria can be transmitted by asymptomatic carriers within healthcare facilities. To date, nothing is known about the prevalence of S. aureus and MRSA among healthcare workers in Madagascar. The objective of our study was to examine the prevalence and clonal epidemiology of nasal S. aureus and MRSA among healthcare workers and non-medical University students in Antananarivo, Madagascar.. This cross sectional study screened nasal swabs taken from students and healthcare workers for S. aureus. Multiplex PCR was performed to identify S. aureus-specific (nuc), MRSA-specific mecA and mecC genes, Panton-Valentine leukocidin (PVL) (lukF-PV), and toxic shock syndrome toxin-1 (TSST-1) specific genes in methicillin-sensitive S. aureus (MSSA) and MRSA isolates. Staphylococcus protein A gene (spa) typing was performed for all confirmed MRSA isolates. The frequency distribution of nasal S. aureus and MRSA of healthcare workers and non-medical students was compared using Pearson's χ(2) test.. Of 1548 nasal swabs tested, 171 (11 %) were positive for S. aureus; 20 (1.3 %) of these isolates were identified as MRSA. S. aureus was detected in 91 of 863 healthcare workers (10.4 %) and in 80 (11.8 %) of 685 students; however, 14 (1.5 %) healthcare workers carried MRSA compared with six (0.9 %) students. Nasal carriage of S. aureus and MRSA was more prevalent in women than in men, and 21 (11.7 %) S. aureus isolates were PVL-positive and 36 (21 %) were TSST-1 positive. The mecC gene was not detected in any isolates. Five different spa types were identified, with spa type t186 being the predominant MRSA clone (16/20).. The results of the present study reveal a low frequency of S. aureus and MRSA nasal carriage in both students and healthcare workers from Antananarivo, Madagascar. The predominant MRSA clone (t186) was previously described in hospitalised patients in Madagascar.

Topics: Adult; Bacterial Toxins; Cross-Sectional Studies; DNA, Bacterial; Enterotoxins; Exotoxins; Female; Health Personnel; Humans; Leukocidins; Madagascar; Male; Methicillin-Resistant Staphylococcus aureus; Multiplex Polymerase Chain Reaction; Nasal Cavity; Prevalence; Staphylococcal Infections; Staphylococcus aureus; Students; Superantigens

Antibiotic residues in dairy products as well as emergence of antimicrobial resistance in foodborne pathogens have been recognized as global public health concerns. The present work was aimed to study a potent antibacterial extract from natural product as an alternative treatment for staphylococcal bovine mastitis. Staphylococcal isolates (n=44) were isolated from milk samples freshly squeezed from individual cows. All staphylococcal isolates were resistant to ampicillin, ciprofloxacin, erythromycin, gentamicin, penicillin, except vancomycin. Rhodomyrtus tomentosa leaf ethanolic extract was accessed for its antibacterial activity and anti-inflammatory potential. The extract exhibited profound antibacterial activity against all of staphylococcal isolates with MIC and MBC values ranged from 16-64 μg/ml and 64->128 μg/ml, respectively. Moreover, the extract also exerted anti-protein denaturation and human red blood cell membrane stabilizing activity. The results support the use of R. tomentosa extract that could be applied to cure bovine mastitis and to reduce inflammatory injury caused by the bacterial infections.

Topics: Animals; Anti-Bacterial Agents; Cattle; Female; Mastitis, Bovine; Microbial Sensitivity Tests; Myrtaceae; Plant Extracts; Plant Leaves; Staphylococcal Infections; Staphylococcus; Thailand

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 anti-staphylococcal activity of an ethanol extract of Rhodomyrtus tomentosa and its pure compound, rhodomyrtone, as well as their effects on staphylococcal biofilm formation and biofilm-grown cells were assessed. MIC and minimal bactericidal concentration values of the ethanol extract and rhodomyrtone against planktonic cultures and biofilms of five clinical strains each of Staphylococcus aureus and Staphylococcus epidermidis, and American Type Culture Collection (ATCC) strains of both species, were 32-512 and 0.25-2 µg ml(-1), respectively. Results from time-kill studies indicated that rhodomyrtone at a concentration of 4× MIC could reduce the number of Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 35984 cells by 99.9% within 3 and 13 h, respectively. The ability of rhodomyrtone and the ethanol extract to prevent biofilm formation and kill mature biofilms was assessed: both demonstrated better activity than vancomycin at inhibiting staphylococcal biofilm formation. In addition, the viability of 24 h and 5-day staphylococcal biofilm-grown cells decreased after treatment with the ethanol extract and rhodomyrtone. The ability to reduce biofilm formation and kill mature biofilms occurred in a dose-dependent manner. Scanning electron microscopy clearly confirmed that treatment with rhodomyrtone at 16× MIC could reduce 24 h biofilm formation and the numbers of staphylococci, whilst at 64× MIC this compound destroyed the organisms in the 5-day established biofilm. These results suggest that rhodomyrtone has the potential for further drug development for the treatment of biofilm-forming staphylococcal infections.

Topics: Anti-Bacterial Agents; Biofilms; Microbial Sensitivity Tests; Microbial Viability; Myrtaceae; Plant Extracts; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis; Vancomycin; Xanthones

The septic arthritis and osteitis treatment is based on germ(s) identification, which is not always obvious if we do not have at our disposal some proper technical platforms. Moreover, the population's low purchasing power compels us to prescribe the most affordable antibiotic. Regarding this context, this article is aimed at modelling a treatment strategy of osteoarticular infections for adult in developing countries, with international recommendations as our basis. It is a retrospective study, which concerned inpatients admitted in the rheumatology-dermatology department of the Antananarivo University Hospital for septic arthritis and osteitis over all clinical patterns. We considered 9 cases including 7 septic arthritis and 2 osteitis. Staphylococcus aureus was found in two patients who had an osteitis, no germ was isolated for the patients with septic arthritis. Ceftriaxone 2 g per day combined with ciprofloxacine 1 g per day by IV route, shifted by oxacilline 3 g per day and by ciprofloxacine 1 g per day peroral proved to be effective for all patients. The international epidemiological data and the medicines cost were used as reference for the choice of antibiotics treatment. Our approach is worth being taken into consideration as an adaptation of the European recommendations to the realities of developing countries. In absence of any particular risk factor for any specific infection, the combination of ceftriaxone Iciprofloxacine IV route, shifted by oxacilline/ciprofloxacine peroral is recommended.

Topics: Adult; Anti-Bacterial Agents; Arthritis, Infectious; Ceftriaxone; Ciprofloxacin; Developing Countries; Drug Therapy, Combination; Humans; Madagascar; Osteitis; Retrospective Studies; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. In developed countries, as methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become limited. In developing countries and especially African countries very little is known concerning the resistance of S. aureus to antibiotics. In Madagascar no data exist concerning this resistance.. To update the current status of antibiotic resistance of S. aureus in Antananarivo, Madagascar.. Clinical S. aureus isolates were collected from patients at the Institut Pasteur of Madagascar from January 2001 to December 2005. Susceptibility tests with 18 antibiotics were performed by the disk diffusion method.. Among a total of 574 isolates, 506 were from community-acquired infections and 68 from nosocomial infections. There was no significant difference in the methicillin resistance rate between community-acquired strains (33 of 506; 6.5%) and nosocomial strains (3 of 68, 4.4%). Many MRSA isolates were resistant to multiple classes of antibiotics. Resistance to tetracyclin, trimethoprim-sulfamethoxazole and erythromycin was more common. Among MRSA isolates resistance rates to rifampicin, fusidic acid, gentamicin and ciprofloxacin were lower than that observed with other drugs easily available in Madagascar. No isolates were resistant to glycopeptides.. The rate of methicillin-resistant S. aureus is not different between community-acquired and nosocomial infections and is still rather low in Madagascar.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Community-Acquired Infections; Cross Infection; Drug Resistance, Bacterial; Female; Humans; Infant; Madagascar; Male; Methicillin; Methicillin Resistance; Microbial Sensitivity Tests; Middle Aged; Prevalence; Staphylococcal Infections; Staphylococcus aureus

Neonatal infections represented the second cause of morbidity at the neonatalogy service of the Maternity Hospital of Befelatanana, and they were the first cause of the perinatal mortality (81%). This prospective study was carried out from May 1997 and December 1998 and had concerned neonatal infections suspicions among newborns. Its purpose was to identify problems with regard to the management of those newborns and to assess the impact of the prevention. Over 14,009 births, 1,877 neonates had infections recorded during the first week of life. Were noticed as main pathogen germs isolated: Escherichia coli, groups B, A, G, D Streptococci and Staphylococcus aureus. The authors conclude that screening and early treatment of materno-fetal infections constitute with asepsis, prevention basis of neonatal infections.

Topics: Adolescent; Adult; Bacterial Infections; Causality; Escherichia coli Infections; Hospitalization; Hospitals, Maternity; Humans; Incidence; Infant Mortality; Infant, Newborn; Madagascar; Morbidity; Neonatal Screening; Primary Prevention; Prospective Studies; Public Health; Risk Factors; Staphylococcal Infections; Streptococcal Infections

The purpose of this study was to evaluate the incidence of acquired resistance to antibiotics in Madagascar. Testing was carried out on total of 1267 strains of medically significant bacteria isolated from specimens sent to the Pasteur Institute of Madagascar in Antananarivo between October 1997 and October 1998. Antibiograms were performed using the diffusion technique on gel media with antibiotic disks. Results were read according to the criteria of the Antibiogram Committee of the French Society of Microbiology. Preliminary findings documented a high incidence of resistance to widely available, low-price antibiotics including penicillin G and tetracycline for which 84 p. 100 and 65 p. 100 of Staphylococcus aureus respectively demonstrated resistance; tetracyclin to which 80 p. 100 of streptococcus were resistant; and ampicillin, cotrimoxazole, and phenicoles to which 60 p. 100, 60 p. 100 and 28 p. 100 of Escherichia coli respectively and 77 p. 100, 83 p. 100, and 71 p. 100 of Shigella sp. respectively were resistant. Second-line antibiotics including penicillin M, macrolides, nalidixic acid, and nitrofuranes were still relatively active, thus providing an effective alternative. Newly developed antibiotics such as fluoroquinolones and third-generation cephalosporines were highly effective but a few resistant strains were observed. Although not representative of Madagascar as a whole, the findings of this preliminary study indicate that acquired resistance must be taken into account in designing simplified decision charts for front-line laboratories, that appropriate information must be made available to health care workers, and that further testing is needed to monitor the evolution of antibiotic resistance.

Topics: Bacterial Infections; Decision Support Techniques; Drug Resistance, Microbial; Enterobacteriaceae Infections; Enterococcus faecalis; Gram-Positive Bacterial Infections; Humans; Incidence; Madagascar; Patient Selection; Population Surveillance; Pseudomonas Infections; Staphylococcal Infections; Streptococcal Infections; Streptococcus agalactiae

An epidemic of A.E.H.C. was broken out everywhere in Madagascar during hot season from September 1990 to May 1991 with an important acuteness in February and March. Clinical symptoms are those of A.E.H.C. to enterovirus with some particularities. Virological study shows cytopathogenic effect of enterovirus and microbiology shows the existence of several bacterial germs particularly staphylococcus epidermidis. The discovery of two cases of streptococcus pneumonia and the absence of chlamydia trachomatis make the originality of our cases. The efficacy of the association antibiotic and steroids is spectacular.

Topics: Conjunctivitis, Acute Hemorrhagic; Enterovirus Infections; Humans; Madagascar; Staphylococcal Infections; Streptococcal Infections