ABSTRACT
Our aim was to study the susceptibility of Staphylococcus aureus to antimicrobial agents and to determine the methicillin-resistant S. aureus (MRSA) prevalence in the Point G teaching hospital in Bamako. METHODS: Columbia blood agar with nalidixic acid and colistin was used for the isolation of S. aureus strains. The diffusion method was used for antimicrobial susceptibility testing. RESULTS: Of 434 non repetitive strains of S. aureus isolated from 2007 to 2009 in the Point G teaching hospital, 297 (68.6%) were from hospital area and 137 (31.4%) were from extra-hospital area. The hospital strains were more resistant to penicillin than the extra-hospital strains (95% versus 88%; p = 0,016). Tetracycline was more active against hospital clinical isolates than extra-hospital clinical isolates (32% versus 21%; p = 0.024). Among 297 S. aureus clinical isolates, 195 (66%) were MRSA and 102 (34%) were methicillin-susceptible S. aureus (MSSA). The MRSA clinical isolates prevalence was higher in hospital area than in extra-hospital area (66% versus 55.5%; p = 0.0418). The MRSA clinical isolates prevalence was higher in the medical wards than in the surgical wards (74.8% vs 34.3%; p < 10-6). Among 251 MRSA clinical isolates, 169 (67.3%) were from urine, 39 (15.5%) from pus, 30 (12%) from blood culture, 7 (2.9%) from vagina and 6 (2.5%) from other sites. The MRSA clinical isolates prevalence was 46% in 2007, 63% in 2008 and 80% in 2009. The MRSA clinical isolates were highly more resistant to penicillin (p < 10-6), to amoxicillin combined with clavulanic acid (p < 10-6), to aminoglycosides (p < 10-6), to macrolides, lincosamides and streptogramins (p < 10-6), to norfloxacin (p < 10-6), to chloramphenicol (p < 10-6), to tetracycline (p = 0,0042), to sulfonamides (p < 10-6), to trimethoprim (p < 10-6), to fusidic acid (p < 10-6), and to fosfomycin (p = 0,0103) than the MSSA strains. The high level resistance to aminoglycosides, fluoroquinolones, macrolides, lincosamides and streptogramins was more frequent in the MRSA strains than in the MSSA strains. CONCLUSION: The MRSA clinical isolates prevalence was very high in the Point G teaching hospital in Bamako, in the medical wards especially. The MRSA strains were drugs multiple resistant.
Notre objectif était d'étudier la sensibilité de Staphylococccus aureus aux antibiotiques et de déterminer la prévalence des souches résistantes à la méticilline au centre hospitalier universitaire du Point G à Bamako. MÉTHODES: L'isolement des souches de S. aureus a été réalisé sur la gélose Columbia additionnée de sang de mouton, d'acide nalidixique et de colistine. L'étude de la sensibilité aux antibiotiques a été faite par la méthode des disques. RÉSULTATS: Sur 434 souches non répétitives de S. aureus isolées de 2007 à 2009 au centre hospitalier universitaire du Point G, 297 (68,6 %) sont d'origine hospitalière et 137 (31,4 %) d'origine extrahospitalière. Les souches hospitalières ont été plus résistantes à la pénicilline G que les souches extrahospitalières (95 % versus 88 %; p = 0,016). La résistance de S. aureus à la méticilline (SARM) a été plus fréquente chez les souches hospitalières que chez les souches extrahospitalières (66 % versus 55,5 %; p = 0,0418). Les plus hautes prévalences de SARM ont été observées dans les services de néphrologie (90 %), de cardiologie (87,5 %) de médecine interne (71 %), d'hématologie-oncologie médicale (66 %) et des maladies infectieuses (65 %). La prévalence des souches de SARM a été de 46 % en 2007, 63 % en 2008 et 80 % en 2009 en milieu hospitalier. Les souches de SARM ont été plus résistantes à la pénicilline G (p < 10−6), à l'association amoxicilline + acide clavulanique (p < 10−6), aux aminosides (p < 10−6), aux macrolides, lincosamides et streptogramines (p < 10−6), à la norfloxacine (p < 10−6), au chloramphénicol (p < 10−6), à la tétracycline (p = 0,0042), aux sulfamides (p < 10−6), au triméthoprime (p < 10−6), à l'acide fusidique (p < 10−6), et à la fosfomycine (p = 0,0103) que les souches de S. aureus sensibles à la méticilline (SASM). Les phénotypes de résistance aux aminosides (KTG, S+ KTG) et aux macrolides, lincosamides et streptogramines (MLSB constitutif) ont été plus fréquents chez les souches de SARM que chez celles de SASM. CONCLUSION: La prévalence des souches de SARM a été très élevée au centre hospitalier universitaire du Point G, dans les services de médecine surtout. Les souches de SARM sont multirésistantes.
ABSTRACT
The objectives of this cross-sectional study were to assess the prevalence and identify predictors of HIV-1 and HIV-2 infection among students in three cities of Mali. Between January and June 2005, we assessed HIV knowledge, attitudes, associated sexual behaviors and tested HIV serostatus among 950 high school and university students in Sikasso, Bamako, and Koulikoro cities, using a combination of enzyme-linked immunosorbent assay (ELISA) and Western blot testing. Univariate and logistic regression analyses were used to determine predictors of infection among students. Mean HIV prevalence was 3.1%, ranging from 1.8% in Sikasso to 3.6% in Bamako. The results showed the presence of all three HIV subtypes in Bamako, though HIV-1 predominated in all cities. Infection rates were slightly higher among males (3.6%) than among females (2.8%), but the difference was not significant. The single significant predictor of HIV infection was knowledge of HIV routes of transmission (p=0.01). HIV prevalence rates observed in this population were higher than general adult prevalence rates previously reported for Mali. HIV/AIDS education and prevention campaigns should be targeted to students at both the secondary and university levels. Students may represent an informative HIV sentinel population for Mali.
