Detection of mecA and panton-valentine leukocidin genes in methicillin resistant staphylococcus aureus isolated from various clinical samples in a tertiary care hospital

Context: Staphylococcus aureus is a Gram positive bacterium which has an impending ability to cause an array of infection ranging from skin lesions to life threatening systemic illness. In the past few decades there is a drastic rise in Methicillin resistant Staphylococcus aureus (MRSA). The acquisition of Staphylococcal cassette chromosome mec (SCC mec) carrying mecA gene leads to Methicillin resistance among Staphylococcus aureus. Aim: The aim of this study is to identify the prevalence of MRSA and identify the SCC mecA and Panton-Valentine Leukocidin (PVL) gene by Polymerase chain reaction (PCR) among Staphylococcus aureus among various clinical isolates in our hospital. Materials and Methods: A prospective cross-sectional study was conducted in a tertiary care hospital at Puducherry. The study was conducted over a period of 1year from January 2014 to December 2014. The isolates were obtained from various clinical samples such as pus, aspirate, urine, blood and sputum. PCR amplification of mecA and pvl genes was performed to check their prevalence among the isolates collected from a tertiary care hospital. PCR reaction mixtures (10?l) contained 1?lTaq PCR buffer (10X) with 15mM MgCl2, 0.1 µl (0.5U) of Taq polymerase (New England Biolabs, US), 0.25mM of dNTP mix (Thermo Scientific, US), 0.25pM each of forward and reverse primers (Eurofins, Bangalore, India) and 10ng of genomic DNA template. Results: Around 228 samples of Staphylococcus aureus isolated from various clinical samples were analyzed for methicillin sensitivity. Out of these samples around 49 (21.49%) samples were MRSA positive isolates. Out of 49 mecA harboring isolates pvl gene was amplified in 26 (53%) isolates. Conclusion: MRSA being a dreadful pathogen has minimal treatment options. PVL gene with added virulence further worsens the clinical outcome among infected patients. Hence the knowledge of its prevalence adds an insight among the infection control practitioners to adhere effective preven