A model of the effect of temperature on the growth of pathogenic and nonpathogenic Vibrio parahaemolyticus isolated from oysters in Korea

Vibrio parahaemolyticus is recognized as the leading cause of human gastroenteritis associated with the consumption of seafood. The objective of this study was to model the growth kinetics of pathogenic and nonpathogenic V. parahaemolyticus in broth and oyster slurry. Primary growth models of V. parahaemolyticus in broth and oyster slurry fit well to a modified Gomperz equation (broth R2=0.99; oyster slurry R2=0.96). The lag time (LT), specific growth rate (SGR), and maximum population density (MPD) of each primary model were compared. The growth of nonpathogenic V. parahaemolyticus was found to be more rapid than that of pathogenic V. parahaemolyticus, regardless of the model medium. In addition, significant (P<0.05) differences in the growth kinetics between pathogenic and nonpathogenic V. parahaemolyticus in broth were observed at 10 °C. When compared to growth in broth, the growth of V. parahaemolyticus was delayed in oyster slurry, and growth was not observed at 10 or 15 °C. The Davey and square root models were identified as appropriate secondary models for predicting the LT and SGR, respectively. For the broth model, the average Bf and Af values for LT were found to be 0.97 and 1.3, respectively, whereas the average Bf and Af values for SGR were 1.05 and 1.11, respectively. The model generated in this study predicted an LT that was shorter and an SGR that was similar to those that were actually observed, which indicates that these models provide a reliable and safe prediction of V. parahaemolyticus growth.