Study on biofilm- forming ability and influence factors of various Vibrio parahaemolyticus strains

Objective: The aim of this study was to investigate the biofilm- forming ability and various adhesion influence factors of different Vibrio parahaemolyticus strains.Methods: Using modified tube test and microtiter- plate test methods, the biofilm adhesion and OD570 value of the 21 strains were made under various factors, then the best biofilm formation strain and a typical strain Vp BJ1.1616 were chose for further characteristic research using modified microtiter- plate test.Results: No obvious correlation were found between biofilm formation and source or pathogenicity of strains, and the strain Vp F29 from food was the best among the 21 strains. The coefficient of variation ( CV = standard deviation / mean* 100) of OD570 nmamong the tested strains at p H ( 6.5 ⁹.5) was from 0.357 to 0.447, and at Na Cl ( 2% ⁴%) was from 0.383 to 0.472.It was also found that both Vp F29 and Vp BJ1.1616 biofilm strongly adhered to the Polyvinyl chloride ( PVC) surface at the following conditions: 32 ~ 37℃, 37℃ separately, the content of TSB was 2.4% to 9.6%. Conclusion: These data showed that Vibrio parahaemolyticus biofilm formation had strain variability and specialty, which provided a basis on the study of the relation between food safety and biofilm.