Isolation and Characterisation of Staphylococcus aureus from Milk Products

The aim of the present study was to assess the occurrence of Staphylococcus aureus in milk products to ascertain the hygienic quality in milk products. The milk products samples were enriched in staphylococcal enrichment broth followed by plating on selective Baird-Parker agar. In the study, S. aureus was present in 14.0% different milk products, namely barfi – 22.0%, paneer – 20.0%, dahi – 12.0%, ice cream – 10.0% and pasteurised milk – 6.0%. In paneer, highest presence of S. aureus was observed in local retailers – 30.0%, followed by brand-I and brand-II with 13.3% each. Likewise, in dahi, local and branded samples had 12.5% and 10.0% occurrence, respectively. The presence of S. aureus in pasteurised milk was 9.0% and 5.5% in brand-I and brand-II while absent in brand-III. The presence of S. aureus in local ice cream was higher (15.0%) than branded items of ice cream (11.1%). In the molecular study, 16sRNA gene was amplified in all the isolates of S. aureus had, whereas coagulase gene couldn't be amplified in any of the isolates. The presence of S. aureus in milk products indicated poor sanitary condition during production, processing and packaging, and thus, a source for food borne illness as S. aureus produces heat-resistant enterotoxin.