Methicillin-resistant Staphylococcus aureus: prevalence and current susceptibility pattern in sikkim

J Glob Infect Dis. 2011 Jan;3(1):9-13. doi: 10.4103/0974-777X.77289.


Background: Prevalence of methicillin-resistant Staphylococcus Aureus (MRSA) strains is reported to be increasing globally.

Objectives: The study was conducted to find the magnitude and antibiotic susceptibility pattern of MRSA infection in a referral tertiary care teaching hospital of Sikkim, India.

Materials and methods: In this cross sectional study, 827 clinical specimens were collected from different departments of Central Referral Hospital. One hundred and ninety-six carrier screening nasal swabs were obtained from health care workers of the hospital. Subsequently, the antimicrobial susceptibility test was performed for the confirmed MRSA isolates as per Clinical and Laboratory Standards Institute (CLSI).

Results: Methicillin resistance was seen in 152 isolates of S. aureus - 111 from clinical specimens and 41 from carrier screening samples. MRSA positivity among males was significantly higher than females. Extremely significant MRSA-positive cases were observed from ages less than 30 years, in-patient cases, particularly with a stay of more than 15 days and with a previous history of intake of broad spectrum antibiotics. Incidentally, there was no significant difference of MRSA positivity with a previous history of hospitalization. The extent of MRSA and drug resistance pattern was significantly different among various samples of S. aureus-positive isolates. The strains tested exhibited decreased susceptibility to vancomycin and imipenem. Most vulnerable of the carrier were the cleaners, that was a significant observation. Incidentally, there was no resistance in the carriers to both vancomycin and imipenem.

Conclusion: MRSA is prevalent in our hospital and strains resistant to methicillin and vancomycin were quite high.

Keywords: Antibiotic susceptibility; MRSA; Sikkim.