Prevalence and antimicrobial susceptibility pattern of Methicillin-resistant Staphylococcus aureus among clinical samples in a tertiary care hospital

ABSTRACT

To determine the prevalence and antimicrobial susceptibility pattern of MRSA isolates among clinical samples in a tertiary care hospital. This cross sectional study was carried out among patients between the age group one and seventy years, admitted to a tertiary care hospital in India. A total of 2850 clinical samples from patients attending various clinical departments were collected over a period of two years. staphylococcus aureus was identified by culture characteristics and confirmed by tube coagulase test. Methicillin resistance was determined by oxacillin [1 micro g] disc diffusion method using MHA with 5% NaCl supplementation. Antimicrobial susceptibility testing was done by Kirby-Bauer's method for all the isolated MRSA strains. The prevalence for age, gender and clinical samples were calculated. Of the total 2850 clinical samples studied, 1262 [44%] samples were from pyogenic materials. 490 [17%] from aspirates and 1098 [39%] from wound secretions of a patients of various clinical departments. 586 samples were positive for S. aureus. Out of the 586 S. aureus isolated, 236 [40.2%] isolates were positive for MRSA and 350 [59.7%] isolates were positive for MSSA. The yield of MRSA was the highest among 20-40 year age group [47.4%], predominantly males and were mostly from surgical post-operative patients [39.8%]. All the 236 MRSA isolates were 100% susceptible to Vancomycin and 100% resistant to Penicillin. The Prevalence of MRSA in our hospital was 40.2%. We conclude that knowledge of prevalence and antibiotic sensitivity pattern of MRSA help the clinician in providing the first line treatment in the health care settings. Also we recommend a universal rapid MRSA screening strategy for patients admitted for surgery in order to control and minimize the spread of MRSA in patients