INCIDENCE OF LISTERIA SPECIES IN SEAFOOD PRODUCTS OF MYSORE, INDIA

Abstract

ABSTRACTListeria monocytogenes is one of the most important foodborne pathogens causing illness in humans and animals. Thus, a study was undertaken to investigate the incidence of Listeria species in fresh and dry fish samples marketed in Mysore, India. A total of 164 fresh and dry fish samples collected from retail outlet shops of Mysore, South India, during the period August 2005 through August 2006 were examined for the presence of Listeria species by using ISO 11290 protocol. The incidence of Listeria species was positive in 62 samples (37.8%), and L. monocytogenes was isolated from only three (1.83%) fresh fish samples. Listeria species in seafood were predominant in the order of Listeria innocua (50) (30.49%), Listeria grayi (eight) (4.9%), L. monocytogenes (three) (1.83%) and Listeria seeligeri (one) (0.6%). All isolates of Listeria species were subjected to polymerase chain reaction (PCR) and confirmed with the genus‐specific set of primers, and special emphasis was given for detection of L. monocytogenes using a species‐specific set of primers. The specificity and sensitivity of PCR were in good correlation with the cultural methods. The results indicated a high incidence of Listeria species and L. monocytogenes in fresh fish samples. This warrants the need for appropriate control measures as this would pose a serious threat to human health.