HYGIENE AND SAFETY OF EDIBLE SNAILS

摘要

The aim of the present work was to determine the microbial indicators and the presence of Salmonella spp. of live snails Helix aspersa and Helix lucorum intended for human consumption. Samples of live wild snails (Helix aspersa and Helix lucorum) from Greek markets and farmed snails (Helix aspersa) from experimental breeding of University of Thessaly were taken for microbiological analysis. The following microbiological parameters were counted: (a) Total Viable Counts on Tryptone Soy Agar, (b) Enterobacteriaceae using Violet Red Bile Glucose Agar (c) Escherichia coli / conliforms using chromogenic agar medium and (d) Enterococcus sp. on Kanamycin Aesculin Azide Agar. Detection of Salmonella spp was conducted as follows: pre-enrichment on Buffered Peptone Water, enrichment on Rappaport-Vasiliadis (RVS) and Mueller-Kaufmann Tetrathionate (MKTTn) broth. Xylose, Lysine Deoxycholate (XLD) and Brilliant Green Agar (BGA) were used to isolate the presumptive Salmonella spp. colonies. Confirmation of presumptive Salmonella spp. colonies was carried out using biochemical tests (API 20E, Biomerieux) and Salmonella 0, V kar Hi anti-sera. Salmonella spp. was detected in the intestines and body of wild snails Helix aspersa and Helix lucorum compare to farmed ones, where no Salmonella spp. was detected. The results showed population differences for all the categories of micro-organisms counted in intestines and body between wild Helix aspersa and Helix lucorum, as well as between wild and breeding Helix aspersa snails. Snails directed for human consumption contain high levels of bacterial populations in intestines and bodies and the presence of pathogens may be possible. The absent of Salmonella spp. in breeding snails shows that the controlled conditions decrease the possibility of pathogen presence and contribute to food safety and public human health.