Prevalence and antibiotic resistance profile of Listeria spp. associated with seafoods from fish catchment areas in Kerala, India

BACKGROUND AND AIM: Listeria monocytogenes is a ubiquitous, intracellular pathogen which has been implicated as a cause of several foodborne outbreaks. This study aimed to generate information on the prevalence and antibiotic resistance profile of Listeria species isolated from seafood. MATERIALS AND METHODS: A total of 400 samples of fresh fish, 100 samples of dry fish and 200 samples each of crustaceans and mollusks were collected from the fish catchment areas. All the samples were subjected to isolation and identification of Listeria spp. by two-step enrichment in UVM broth and plating on selective agar media (PALCAM) and then subjected to molecular characterization. L. monocytogenes isolates obtained during the study were subjected to serotyping by multiplex polymerase chain reaction. The isolates were also subjected to antibiotic sensitivity test. RESULTS: The prevalence of L. monocytogenes in seafoods in the present study was 0.55%. The isolates of L. monocytogenes were found to possess all virulence genes, namely, iap, hlyA, actA, prfA, plcA, and inlA. All the isolates belonged to serotype 4b. The occurrence of Listeria innocua was found to be more and was detected in 16.77% of seafood samples. Antibiotic sensitivity test revealed that all isolates were resistant to cefixime but were sensitive to almost all other commonly used antibiotics. CONCLUSION: The presence of Listeria spp. in raw seafood samples augments the need for implementation of good hygienic practices during the handling and processing of seafoods to safeguard the health of the consumers.