Molecular epidemiology of methicillin resistant staphylococcus aureus colonizing the anterior Nares of school children of Udupi Taluk.

ABSTRACT

Context Community associated methicillin resistant Staphylococcus aureus (CA‑MRSA) cause serious skin and soft tissue infections including necrotizing fasciitis and necrotizing pneumonia. Production of Panton Valentine Leucocidine (PVL) toxin is implicated in its enhanced virulence. A variant of epidemic MRSA‑15 (EMRSA‑15) which produces PVL toxin has been isolated and characterized by pulsed-field gel electrophoresis (PFGE) method from the Indian population both in hospital and community settings. Aims: Identify the epidemiological type of MRSA colonizing the anterior nares of school children in Udupi taluk. Settings and Design: The study population included children of the age group of 5-16 years belonging to the Udupi taluk of Karnataka, India. A total of 1503 children were screened for MRSA colonization during July 2009 to December 2010. Materials and Methods: PVL assay, Staphylococcal Cassette Chromosome (SCC) mec typing and PFGE typing were carried out with all the MRSA isolates. Statistical Analysis Used Frequency distribution of different variables was assessed by SPSS. Results: Among the 1.1% of MRSA, 58.8% (10/17) of isolates were positive for pvl and 41.7% (7/17) were identified as SCC mec type IV. PFGE patterns of all the strains were identical with Indian variant EMRSA‑15; however they were different from classical EMRSA‑15 in 3-4 bands. Conclusions: The Indian variant EMRSA‑15 gains much epidemiological relevance owing to the acquisition of pvl gene. In spite of low prevalence of nasal colonization of MRSA, emergence of the virulent Indian variant EMRSA‑15 in our community is a worrisome fact to be reckoned with.