[Susceptibility to antibiotics of Staphylococcus aureus strains]

Staphylococcus aureus is a very important pathogen in humans about 20% of all bacterial infections are caused by S. aureus. Because the staphylococcal sensitivity patterns have changed, the aim of this study was to investigate the current susceptibility of the S. aureus strains to 9 antibiotics: penicillin (P), amoxacillin/clavulanic acid (AMC), erythromycin (E), cortimoxazole (SXT), tetracycline (T), chloramphenicol (C), mupirocin (MUP), gentamicin (Ge) and vancomycin (Va). Susceptibility testing was performed by disc diffusion technique, by the procedure outlined by the National Committe for Clinical Laboratory Standards (NCCLS). Susceptibility to methicillin was determined using 5 micrograms methicillin disks. beta-lactamase production in the penicillin-resistant strains was detected with nitrocefin impregnated disk (Cefinase, BBL Microbiology system). The microbiological characteristics of the samples: 338 of the isolates were derived, from noses and the throats 382--from surgical wound secretions. The analysis of the results showed that most S. aureus strains (82.8%) are penicillin resistant and beta-lactamase producing 13.5% of all strains were methicillin-resistant. 16.5%--were erythromycin resistant; 3.2%--were cotrimoxazole resistant; 51.4%--were mupirocin resistant; 20.6%--were gentamicin resistant. All of the strains were vancomycin sensitive.