NASAL COLONIZATION OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS AMONG CLINICAL POSTGRADUATES IN A COASTAL KARNATAKA MEDICAL COLLEGE - PREVALENCE AND ANTIBIOGRAM PATTERN

Objective: The incidence of community-acquired and hospital-acquired Staphylococcus aureus infections has been rising with increasing emergence of drug-resistant strains called methicillin-resistant S. aureus (MRSA). The prime objective of the study was to ascertain the prevalence of carriage rate of MRSA among the clinical postgraduate students of a medical college of Coastal Karnataka, India. Methods: A total of 133 clinical postgraduates have participated in the present study. Swabs from both anterior nares were collected and processed for S. aureus from the consenting participants after giving a set of questionnaires. The isolated strains of S. aureus were screened for methicillin resistance by the modified Kirby-Bauer method using cefoxitin (30 μg) disc. Antibiotic susceptibility testing for all isolates of S. aureus was also done against other antibiotics. E test was used to know vancomycin resistance for MRSA. Results: The numbers of S. aureus isolated of 133 participants were 22 (16.5%). Of 22 isolates of S. aureus, 12 were MRSA (54.5%). The MRSA carriage rate of clinical postgraduates of a medical college from Coastal Karnataka, India, was 9%. All the MRSA isolates were susceptible to vancomycin and teicoplanin. Contact with chronic patients and consumption of antibiotics in past 6 months were found to be statistically significant as the risk factor associated with the acquisition of S. aureus/MRSA carriage status among the participants. No vancomycin-resistant S. aureus was reported from the present study. Conclusion: The S. aureus and MRSA nasal carriage rates of clinical postgraduates recorded in this study were significantly high when compared with the general population. This could be due to their continuous exposure to patients in clinical settings. It is desirable that these students must receive sufficient knowledge regarding control measures to avoid the spread of MRSA infection in hospitals.