MOLECULAR DETECTION OF LISTERIA MONOCYTOGENES AND L. INNOCUA ISOLATES IN FISH SKIN SWABS FROM RETAIL FISH MARKETS IN WEST BENGAL, INDIA

Listeria monocytogenes is a pervasive pathogen that survives well in nature and recognised from various animal food including contaminated fish and fish products worldwide and in India.The presence of L. innocua, a non-pathogenic Listeria, indicates improper hygienic practices suitable for L. monocytogenes contamination in food.To detect contamination by Listeria innocua and monocytogenes in the skin of freshwater fish rohu (Labeo rohita), 234 swab samples were collected from retail fish markets of Kolkata (n=165) and South 24 Parganas (n=69) districts of West Bengal by standard microbiological and molecular biology protocols. One hundred four (44.44%) Listeria spp. strains were identified by cultural characteristics, biochemical tests, and PCR technique targeting genus-specific prs gene PCR, of which 6 (2.56%) and 11 (4.7%) isolates were detected as L.monocytogenes and L.innocua targeting the lmo1030 and lin0464 genes, by PCR, respectively. The occurrence of L. monocytogenes was found less in this study. Regular monitoring systems should be practiced to uphold the quality of Indian food and maintain food safety standards.