Peptidase T is related to swimming motility and biofilm formation of Vibrio parahaemolyticus

Abstract:

The pepT gene of Vibrio parahaemolyticus encodes a metal dependent peptidase T (PepT) that catalyzes the N-terminal amino acid of tripeptides with high specificity,and thus it is also called aminopeptidase T.Studies have found that most aminopeptidases are involved in protein metabolism of bacteria and regulating the activity of tripeptides,but little is known about PepT in bacterial virulence and pathogenicity.[Objective] In this study,PepT was chosen to explore the effect of gene deletion on the biological characteristics and pathogenicity of V.parahaemolyticus.[Methods] The pepT gene deletion mutant ΔpepT and the complementary strain CΔpepT were generated and their differences of various strains in motility,biofilm,environmental tolerance and cytotoxicity were compared.[Results] Compared with the wild-type strain,ΔpepT had significantly decreased transcription level of polar flagella and reduced swimming mobility.Furthermore,the biofilm formation ability of ΔpepT was weakened,but there were not statistically significant in the swarming mobility and environmental tolerance.In addition,the pepT gene deletion resulted in remarkably lowered cytotoxicity and virulence of V.parahaemolyticus in mice.[Conclusion] The pepT gene deletion affects the swimming motility and biofilm formation ability as well as the pathogenicity of V.parahaemolyticus.