Characterization of Yersinia species in Milk and Milk Products

Yersiniosis is an emerging disease of public health significance caused by Yersinia species. Y. enterocolitica is an important pathogen of milk borne diseases that can grow at refrigeration temperature and its presence in milk is of great public health importance. In the present study, a total of 2,431 samples comprising of milk and milk products were analysed for the presence of Yersinia species. Among them, 20 were confirmed as Yersinia species by biochemical tests and 18 were confirmed by commercial Enterobacteriaceae identification Kit method. In polymerase chain reaction (PCR) assay, 9 isolates were identified as Y. enterocolitica. Out of nine, 4 were found to harbour any one of the virulent genes (ail, virF, rfbC and toxigenic yst) specific for pathogenicity. In this study, Yersinia species were found to be the highest in raw milk (65%) followed by buttermilk (20%), ice cream (10%) and paneer (5%), whereas, no incidence was found in pasteurized milk and khoa. Antibiotics like ciprofloxacin and tetracycline were most effective against Y. enterocolitica. Spice oils like cinnamon and clove oil showed highest inhibition zones against Y. enterocolitica.