Frequency and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus.

OBJECTIVE To determine the frequency of methicillin resistant Staphylococcus aureus and its antimicrobial susceptibility pattern in patients reporting to Combined Military Hospital (CMH), Pano Aqil. STUDY DESIGN A non-interventional, cross-sectional study. PLACE AND DURATION OF STUDY Pathology Laboratory, Combined Military Hospital (CMH), Pano Aqil, from December 2005 to January 2008. METHODOLOGY Strains of Staphylococcus aureus were isolated from a variety of clinical specimens. Standard methodology, using modified Kirby-Bauer disk diffusion method, was adopted for antibiotic sensitivity test. The MIC of oxacillin and vancomycin was performed by E-strips, for MRSA isolates and isolates revealing vancomycin resistance on disk diffusion. RESULTS A total of 195 hospital and 42 community acquired isolates were tested. Forty-seven (19.8%) non-duplicate strains were found to be methicillin resistant Staphylococcus aureus (MRSA); methicillin resistance did not differ among hospital strains (n=42) as compared to community ones (n=5, p=0.1555). No isolates from the community and hospital acquired showed resistance to vancomycin. Community and hospital acquired isolates revealed higher resistance against penicillin and doxycycline than against ciprofloxacin, erythromycin, gentamicin and chloramphenicol. However, resistance against these antibiotics did not differ significantly among community and hospital acquired isolates. CONCLUSION Increase in prevalence of MRSA is impending in future, appealing preventive measures to be adopted. However, Staphylococcus aureus resistant to vancomycin was not observed.