Phenotypic and Virulence Characterization of Pathogenic Vibrio parahaemolyticus

Overall, foodborne bacterial infections from Vibrio species (other than those caused by toxigenic V. cholerae and V. vulnificus) are estimated to be responsible for 5000 illnesses annually in the U.S. V. parahaemolyticus is the most frequent cause of foodborne Vibrio-associated gastroenteritis. Human illness from Vibrioparahaemolyticus is most commonly associated with the consumption of seafood, primarily raw or improperly cooked shellfish. Since 1996, a single strain of V.parahaemolyticus, referred to as the O3:K6 serovar, has been associated with twofoodborne outbreaks in the U.S. The association of this O3:K6 strain with large-scaleoutbreaks of illness suggests the emergence of a "new" V. parahaemolyticus strain that may have an enhanced ability to cause disease. Investigations into the spread anddistribution of V. parahaemolyticus and development of testing protocols and sampling guidelines have been hampered by a lack of methods for differentiating harmful strainsfrom non-pathogenic strains and subtypes. U.S. regulatory agencies with authority over the shellfish industry currently lack analytical procedures for the rapid detection of dangerous V. parahaemolyticus strains. The overall objective of this project is to contribute to enhancing the safety of seafood consumed in the U.S. by providing essential information for development of rapid strategies for detecting dangerous strains of V.parahaemolyticus. Specifically, the investigators will compare characteristics ofdifferent V. parahaemolyticus subtypes, including the newly emerged O3:K6 strain, to identify traits specific to pathogenic V. parahaemolyticus subtypes.