Abstract:
Listeria monocytogenes is a foodborne pathogen commonly found in food and environment. Raw and market milk samples (n= 767) were collected at different levels of collection and processing for isolation of Listeria species. The samples taken included cow milk collected at udder level, from the milk cans, milk receiving centres, processing unit and market. Samples were enriched in Listeria enrichment broth followed by plating on PALCAM agar. Overall, 10.56 percent of the samples (81 of 767) were positive for Listeria species.Out of these 37 (4.82 percent) were confirmed as L.monocytogenes.Other Listeria species isolated were L.innocua (5.47 percent), L.ivanovii (0.13 percent) and L.grayi (0.13 percent). Maximum isolates were recovered from samples collected at market followed by samples at milk processing unit. L. monocytogenes isolates were serotyped using multiplex PCR method. A larger proportion of isolates (26) belonged to the group corresponding to serovars 1/2a, 1/2c, 3a, and 3c. Serogroup corresponding to serovars 4b, 4d and 4e was detected in two strains, while serogroup 1/2b, 3b, 4b, 4d, and 4e was detected in nine strains. This study demonstrates the prevalence of L. monocytogenes in raw and market milk and the need for good hygienic practices to prevent its entry into the food chain.