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Page No. : 19-23

ABSTRACT

The present study was undertaken with the objective of isolating and identifying Listeria spp. from milk and milk products sold at retail markets in the city of Navsari, Gujarat. A total of 100 samples comprising 50 milk and 50 milk product were collected aseptically from local market. Presumed Listeria spp. were subjected to battery of standard biochemical test for identification of Listeria spp. Cultures identified as Listeria monocytogenes were further subjected to detection of different virulence associated genes viz., inlA, inlB, plcA and plcB. Out of all the 100 samples tested 8 milk and 2 ice cream samples showed presence of Listeria spp. Species-wise 4 isolates of L. seeligeri, 3 isolates of L. monocytogenes and 1 isolate of L. welshimeri were obtained from milk samples and 2 isolates of L. welshimeri were obtained from ice cream samples. All the L. monocytogenes isolates confirmed on the basis of biochemical and in-vitro pathogenicity tests targeting inlA, inlB, plcA and plcB genes.

Keywords: Listeria species, milk and milk products, pathogenicity