Overnight Enumeration of Vibrio parahaemolyticus In Seafood by Hydrophobic Grid Membrane Filtration

Abstract

A method was developed for direct enumeration of Vibrio parahaemolyticus in foods by hydrophobic grid membrane filter. The method consisted of a 4-5 h resuscitation step to recover injured cells, followed by overnight incubation at 42°C on V. parahaemolyticus Sucrose (VPS) agar, a new selective and differential medium. The confirmation rate of typical colonies on VPS agar was greater than 98%. The new method produced significantly higher counts of V. parahaemolyticus than the FDA method (P<0.01) when tested with chill-, freeze- or heat-stressed samples, and was equivalent to the FDA method (P>0.05) for recovery of osmotically stressed V. parahaemolyticus .