Antibiotic Resistance Pattern of Methicillin Resistant Staphylococcus aureus Isolated From Clinical Specimens

Methicillin Resistant S. aureus poses serious threat to human health since the mortality and morbidity rate due to S. aureus infection is significant. In the present study, a total of 37 S. aureus strains isolated from 1078 clinical were tested against various antibiotics. Antibiotic susceptibility of the isolated S. aureus was carried out using disk diffusion method. The MIC and MBC of different antibiotics were determined by tube dilution assay and disk diffusion technique. The maximum prescribed antibiotic groups were cephalosporins and penicillins. The most resistant group was penicillin followed by aminoglycoside, cephalosporins and quinolones. The order of resistance of S. aureus against various antibiotics was ampicillin (92.10%), cloxacillin (61.29%), cefradine (60%), ciprofloxacin (59.35%), gentamicin (58.06%). There was no resistant isolate against vancomycin; however, four isolates (10.52%) had shown intermediate sensitivity. MIC and MBC of five major groups of antibiotics namely, penicillins, cephalosporins, aminoglycosides, quinolones and vancomycin were also determined. In-vitro study of MBC of the five groups of antibiotics showed 2 to 3 fold two-fold dilution higher value than in MIC of each group of antibiotic. Only MBC of vancomycin was in the range of 1 to 2 two-fold dilutions higher than their MICs.