Characterization of Methicillin resistant Staphylococcus aureus (MRSA) from various clinical samples at tertiary care centre of Dhiraj Hospital, Piparia, Vadodara, Gujarat

Background: Over the past decades, the emergence of Methicillin resistant S. aureus (MRSA) has changed the landscape of S. aureus infections around the globe. Aim: Present study was aimed to find out the prevalence of MRSA strains, and evaluate its antibiogram to other common antibiotics. Materials and methods: Total 120 samples were collected from various patients of Dhiraj Hospital, Vadodara, Gujarat. All specimens were inoculated on blood agar and MacConkey agar (HiMedia) and mannitol salt agar Inoculated plates were incubated at 35 ̊C. After overnight incubation, suspected S. aureus colonies were confirmed by gram staining, catalase test and coagulase (slide and tube) tests, which were performed as per standard guidelines. Disk diffusion method was performed as per Clinical and Laboratory Standards Institute (CLSI) guidelines. A peptone water suspension equivalent to 0.5 McFarland standard was prepared from isolates. A swab was dipped in suspension and streaked over surface of a Mueller- Hinton agar. Sensitivity to Cefoxitin (30 μg) disk was also tested. Results: Out of 120 samples, 73 strains (60.8%) were found to be MRSA with the prevalence higher in males (52/73) compared to females (21/73). Strains were mainly isolated from the pus samples (70%), followed by sputum (11%), blood and urine samples (8%) each. Highest rate of isolation of MRSA was from the orthopedics ward (23%), followed by surgery (22%), medicine (16%), recovery (12%), ICU (11%), pediatrics (10%), obstetrics (5%). Majority of the MRSA strains were resistant to erythromycin (76.7%), Co-trimoxazole (71%) and (61.6%) resistance with Gentamycin and Clindamycin. All strains were resistant to penicillin (100%). The optimistic finding was its 98.6% sensitivity to Linezolid and Vancomycin. Conclusion: The results of the present study showed a high prevalence of (60.8%) MRSA during April to September 2015. The treatment options for MRSA strains have been restricted to potentially toxic antimicrobials like vancomycin, clindamycin. This poses a serious problem for antibiotic therapy of S. aureus infections and leads to high morbidity and mortality. To prevent MRSA infection control measures like hand washing and other aseptic techniques have been implemented strictly.