Molecular Characterization of Listeria monocytogenes in white meat samples from Punjab, India

A study was undertaken to assess the prevalence of Listeria monocytogenes in white meats in the Punjab, India. A total of 335 samples including 115 samples of chicken, 75 samples of pork and 145 samples of fish were collected from retail outlets. Isolation of the pathogen was done by selective enrichment in University of Vermont Medium I and II and plating onto PALCAM agar. The recovered Listeria isolates were subjected to in-vitro pathogenicity assays and multiplex PCR targeting virulence-associated genes (prfA, plcA, actA, hlyA and iap) of L. monocytogenes. A total of thirty one (31) L. monocytogenes strains were isolated from meat samples with the prevalence of L. monocytogenes as 9.2%. Maximum prevalence was seen in fish (19.3%) followed by chicken (1.7%) and pork (1.3%). All isolates recovered from the study exhibited pathogenicity in in-vitro pathogenicity assays as well as possessed all the virulence related genes. Thus, the presence of pathogenic strains of L. monocytogenes in white meats with a prevalence of 9.2% appeared to be a cause for concern with profound public health implications.