Abstract

Objective: The present study was aimed to identify and characterize sasX gene in methicillin resistant Staphylococcus aureus (MRSA) isolates from north east India and further analysing its role in biofilm formation and pathogenesis. Methods: A total of 15 0 laboratory adopted S.aureus isolates were investigated for antimicrobial susceptibility patterns using 8 commercially used antibiotics of different groups. The MRSA strains identified were further screened for the presence of sasX gene by using polymerase chain reac tion (PCR). The comparison of sasX+ and sasX- MRSA isolates were further studied for biofilm production by in vitro methods: Tube Method (TM) and microtiter Plate assay (adhesion assay). Results: Out of 15 0 isolates, 24 were found resistant to methicillin among which 8 strains were found harbouring the sasX gene. All these isolates were also found highly resistant to Oxacillin, Methicillin and Penicillin antibiotics. The formation of bacterial aggregates and promotion of biofilm formation was observed much higher in sasX+ MRSA isolates as compared to sasX-MRSA isolates. Conclusion: The overall results signifies that the sasX gene more likely facilitates biofilm production, promotes cell adhesion and helps i n immune evasion mechanisms, thus is a major risk factor which needs to be further investigated. This is probably the first study from India reporting the isolation and characterization of sasX gene in MRSA isolates.