Effect of temperature on pathogenic and non-pathogenic Vibrio parahaemolyticus biofilm formation

Biofilm formation is crucial for the environmental survival and transmission of Vibrio parahaemolyticus, an important food-borne pathogen in seafood. The biofilm developmental process of pathogenic (n = 22) and non-pathogenic (n = 17) V. parahaemolyticus strains on polystyrene microtiter plates under 15 degrees C, 25 degrees C and 37 degrees C was investigated using crystal violet staining, and validated by confocal laser scanning microscopy. The results indicated that biofilm developmental process at 15 degrees C and 25 degrees C were divergent, biofilm formation increased continuously at 15 degrees C, while at 25 degrees C biofilm formation increased gradually and peaked at 12 h. Also the biofilm formation was dramatically elevated at 25 degrees C in comparison with that at 15 degrees C and 37 degrees C. Additionally, pathogenic strains, on average, formed more biofilm than nonpathogenic strains at all temperatures measured. Moreover, extensive strain variability was observed during biofilm formation and indexed using the coefficient of variation (CV). This index increased with increasing temperature and this index, at all temperatures, peaked after 12 h. The results of this study provide insight into the developmental process of biofilm, which allow us to further optimize strategies to control V parahaemolyticus biofilm in food industry. (C) 2016 Elsevier Ltd. All rights reserved.