Occurrence of nuc gene in Staphylococcus aureus from milk samples of different regions of West Bengal

Abstract

Staphylococcus aureus is a Gram positive commensal of the mammalian body, commonly found in the respiratory tract, skin and mammary gland. Bovine milk is a major source of S. aureus. Various factors play a role in the production of pathogenicity of the bacterium including enzymes like thermonuclease, encoded by nuc gene. The present study was carried out for the isolation of S. aureus in bovine milk and determination of the occurrence of nuc gene in them. Out of 168 milk samples, 146 S. aureus strains (86.90%) were isolated, of which 49 S. aureus strains were positive for nuc gene (32.88%) in polymerase chain reaction (PCR). In the study, highest occurrence of nuc positive S. aureus was found in new alluvial zone (55.8%) and least in red laterite zone (3.77%). This indicates wide variation in the presence of nuc gene containing S. aureus in different agro-climatic regions of West Bengal that need further studies to reveal its implication, if any.