Sensitivity pattern of methicillin resistant Staphylococcus aureus isolated from patients admitted in a tertiary care hospital of Pakistan

BACKGROUND AND OBJECTIVES: Methicillin resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen causing significant morbidity and mortality. The aim of this study was to evaluate in vitro activities of different antibiotics against methicillin resistant Staphylococcus aureus. MATERIALS AND METHOD: The study was conducted over a period of one year (January 2009 – December 2009) in the Department of Microbiology, Army Medical College, the National University of Sciences and Technology, Pakistan. One hundred and thirty-nine Methicillin resistant Staphylococcus aureus isolated from the clinical specimens at Rawalpindi Military Hospital were subjected to in vitro susceptibility against various antimicrobials using Kirby Bauer disc diffusion technique. RESULTS: All the isolated MRSA organisms were uniformly susceptible to vancomycin, linezolid and tigecycline. Other drugs which were found to be effective were chloramphenicol, and rifampacin. Most of the MRSA were isolated from pus samples. CONCLUSION: Vancomycin, tigecycline and linezolid were effective against methicillin resistant strains of S.aureus. This study suggests that chloramphenicol and rifampacin also have good in vitro efficacy for methicillin resistant S. aureus infections. Oral dosing option for linezolid, chloramphenicol and rifampacin can allow earlier discharge of hospitalized patients and thus reduce health care expenses as well as help reduce the chances of vancomycin resistant strains emergence.