Molecular Characterisation of Escherichia coli Isolates from Milk and Milk Products

Abstract

The present study was aimed at characterising the Escherichia coli isolates (71) obtained from milk (raw milk – 44 and pasteurised milk – 12) and milk products (ice cream – 11 and shrikhand – 4) with their molecular typing. The study revealed 12.6% (9/71) Shigatoxigenic strain with their presence in raw milk (13.6%, 6/44), ice cream (9%, 1/11) and shrikhand (50%, 2/4). However, none of the E. coli isolates from pasteurised milk found positive for Shigatoxigenic strain. The enteropathogenic strains were 4.2% (3/71) with their presence in raw milk (4.5%, 2/44) and ice cream (9%, 1/11), whereas enteropathogenic strain was absent in pasteurised milk and shrikhand. The occurrence of enterotoxigenic heat-labile strains (elt) - 13.5% (6/44) and heat-stable strains (est)- 4.5% (2/44) in raw milk with overall presence of 8.4% (6/71) and 2.8% (2/71), respectively, for elt and est. These strains were not found in pasteurised milk, ice cream and shrikhand. The study revealed the presence of toxigenic strains in raw milk as well as processed products, which is matter of concern as the pathogen had shown public health hazard in many counties across globe.