Cold adaption behaviors of Vibrio vulnificus and Vibio parahaemolyticus in oysters

Vibrio vulnificus is an estuarine bacterium that can cause primary septicemia as well as other serious wound infections. Vibrio parahaemolyticus is a gram-negative, halophilic bacterium that may cause gastroenteritis, diarrhea, headache, vomiting, nausea, abdominal cramps and is the leading cause of gastroenteritis in United States. Consumption of raw oysters is believed to closely relate with infection with Vibrio vulnificus and Vibrio parahaemolyticus. All strains of V. parahaemolyticus produce tlh genes and the major virulence factors of V.parahaemolyticus are the tdh and trh genes. This study was conducted to determine if Vibrio vulnificus and Vibrio parahaemolyticus clinical and environmental strains display different behaviors at refrigeration temperature. The effects of three different temperature treatments were investigated in this study. In addition, the cold adaption behaviors of different gene-containing Vibrio parahaemolyticus in broth under three different temperatures 5, 8, and 10oC were also studied. Results obtained from this study showed clinical and environmental strains of Vibrio vulnificus and Vibrio parahaemolyticus in oysters had significant differences in growth and survival at specific days under different refrigeration temperature treatments. When different gene-containing Vibrio parahaemolyticus strains were stored at 5oC over 10 days, all strains were able to survive but not grow. At 8oC all of the V. parahaemolyticus strains were able to survive and grow. At 10oC, two of the V. parahaemolyticus strains survived and grew while the V. parahaemolyticus 132 X 5 strain survived but did not grow.