PRESENCE OF Listeria SPECIES IN FRESH SALAD PRODUCTS COLLECTED FROM QUETTA PAKISTAN

In this study prevalence of Listeria spp. particularly L. monocytogenes, L. seeligeri and L. ivanovii, was determined from commonly consumed salad items. Salad samples (n = 200) were collected from local markets and further characterized as 50 samples of each: rocket, parsley, coriander and lettuce. Listeria spp. was isolated and identified by conventional microbiological methods and polymerase chain reaction (PCR) to evaluate the prevalence of different Listeria spp. in salad items. Out of 200 salad samples 18% (36/200) were found positive for Listeria spp. The parsley was found to be least contaminant among the analyzed salad samples with detection rate of 16% (8/50) followed by coriander 18% (9/50), lettuce 18% (9/50), and rockets 20 /"0 (10/50). Prevalence of 2%, 3.5% and 12.5% was reported from fresh salad products for L. tnonocytogene.s, L. seeligeri, and L. ivanovii, respectively. It was concluded that fresh salads were contaminated with Listeria spp. which can present a serious health hazards to potential consumers. The monitoring programs, food safety legislation and minimal processing conditions to control the microbial contamination should be exercised throughout the food supply chain.