Isolation and Identification of Listeria monocytogenes from Raw Vegetables and Meat Sold in Quetta Pakistan

Water and soil have been reported as the pivotal reservoirs for Listeria monocytogenes and its subsequent transmission to food chain, plant material and animals. In present study, 800 food samples consisting of beef and chicken meat, milk, salads and fresh vegetables were collected from retail markets of Quetta, Pakistan. Multiplex PCR was employed to identify the prevalent species and genes associated with virulence. Only 10 (1.25%) samples were found contaminated with Listeria monocytogenes. Milk samples were the most contaminated as 4 samples collected from retail shops or dairy farm were found positive for Listeria. While 2 samples of each beef, chicken meat and salad were contaminated with Listeria. The virulent genes inlA, inlB, prfA, hlyA, actA, plcA and iap were detected in all 10 positive samples for Listeria. The positive samples inventories were analyzed and were found that water used to wash the meat and vegetables was contaminated with Listeria. This study concludes that better hygienic measures should be adopted to keep the food material germ free.