Abstract: In order to study the effect of growth heterogeneity of Vibrio parahaemolyticus (Vp) on food safety risk under oligotrophic conditions: different dilutions (100%, 75%, 50% and 25%) of standard TSB+ (3% NaCl) medium, 20 Vp strains isolated from prawns and shrimps were selected. A first-order growth model was fitted for each strain, and second-order growth parameters were analyzed. The results proved that the modified Gompertz first-order model was fitted to the growth data of the Vp strains well, with correlation coefficient R2 of 0.791–0.997. There was no significant difference in the maximum specific growth rate (P > 0.05) under the same nutrient concentration among Vp strains from different sources. The growth parameters of Vp strains were different under different oligotrophic conditions. Through comparison of the present results with those of previous studies, we found that different initial inoculation amounts of Vp strains would also cause the growth heterogeneity of the strains. In summary, Vp strains had great growth heterogeneity under different oligotrophic conditions. The results of this study will contribute to more accurate food safety risk assessment and more scientific prevention and control of foodborne pathogens.

Key words: Vibrio parahaemolyticus; oligotrophic conditions; growth heterogeneity; growth model