Evaluation of antibiotic resistance pattern in clinical isolates of Staphylococcus aureus

Staphylococcus aureus is a common skin colonizer as well as opportunistic pathogen causing serious diseases including bacteremia, endocarditis and a number of different infections. It has a unique ability to swiftly respond and develop resistance for every other antibiotic introduced against it. The prevalence of antibiotic resistant strains of S. aureus is increasing on an alarming rate, which not only restrains the treatment options but the economic deprivation sustained due to infections of this superbug are incomputable. In our study, antimicrobial resistance patterns for 13 different antibiotics were evaluated in non-duplicate isolates of MSSA and MRSA isolated from different clinical samples (i.e. urine, pus, HVS, blood, tissue, wound and ear swabs). Most cultures were identified as multi-drug resistant (MDR). The highest resistance was recorded against ampicillin and erythromycin (88% each), while resistances against oxacillin, fosfomycin, cefoxitin and ciprofloxacin were also worrisome. No strain was sensitive to all antibiotics. Resistance levels of MSSA against ampicillin, erythromycin, fosfomycin and fusidic acid were also high. Least level of resistance was observed in case of vancomycin. Only 12% isolates were resistant to vancomycin, among which 24 were MRSA and 6 was MSSA.