The Bacteriological Profiles of Freshwater Snail (Pila Ovata) Subjected to Microcosms Simulating Local Storage Conditions

Freshwater snails (Pila ovata) were collected and subjected to four different storage microcosms: body of stagnant water (BSW), body of water changed intermittently (BWCI), hibernating condition (HC) and depuration process (DP). Samples from the different microcosms were analysed for microbiological profiles and dynamics. A significant (P= 0.05) increase (≈1.30 log c.f.u g⁻¹) occurred in samples exposed to BSW. In contrast, unappreciable change was observed in samples subjected to BWCI. Much higher microbial populations were found in the intestines. Hibernation resulted in initial (i.e. within the first 3 months) microbial decrease but increase occurred thereafter. A more heterogeneous bacterial flora was observed at the initial stage of HC but anaerobic spore-formers dominated at the end of the HC. A significant (P= 0.05) microbial decrease occurred within 2 days of DP but thereafter remained virtually unchanged. The pH of samples exposed to BSW increased drastically. The observed microbial profiles have demonstrated the impacts of different microcosms on the potential risk or safety of freshwater snails to consumers. These therefore have underscored the importance of adequate processing/cooking prior to consumption of freshwater snails.