Impacts of Lactobacillus plantarum in Depuration for Reducing Vibrio parahaemolyticus in Pacific Oysters (Crassostrea gigas)

This study investigated potential application of lactic acid bacteria (LAB) in depuration for reducing Vibrio parahaemolyticus in oysters. Lactobacillus plantarum ATCC 8014, which exhibited strong bactericidal effects against V. parahaemolyticus in vitro, was added to artificial seawater for depuration of Pacific oysters (Crassostrea gigas) inoculated with V. parahaemolyticus BE 98-2029 (O3:K6) to levels of about 10(4) MPN/g at 15 +/- 1 and 10 +/- 1 degrees C. Application of L. plantarum ATCC 8014 treatment (10(7) CFU/mL) in oyster depuration did not enhance reductions of V. parahaemolyticus in oysters depurated at 15 +/- 1 degrees C but significantly decreased (p < 0.05) levels of V. parahaemolyticus in oysters depurated at 10 +/- 1 degrees C after 5 days (3.40 log reductions) when compared with controls (2.75 log reductions). It is not clear if a competitive exclusion by LABs to compete with V. parahaemolyticus binding sites in oyster tissues plays a role in the reduction of V. parahaemolyticus in the oysters. Further studies utilizing different types of LABs in oyster depuration might provide additional knowledge for application of LAB in depuration for decontaminating V. parahaemolyticus in oysters.