VcDsbA enhances bioflim formation by stimulating MSHA expression in Vibrio cholerae

Abstract:

[Objective] Biofilm plays an important role during the infection cycle of Vibrio cholerae. In this study, we try to demonstrate the role of VcDsbA in the biofilm formation of V. cholerae.[Methods] By making the VcDsbA inframe knock-out construct, the vcdsbA null mutant (ΔdsbA) strain was obtained. And the complemented strain (CΔdsbA) was constructed by transferring a plasmid-coded VcDsbA expressed under the control of arabinose to ΔdsbA strain. Crystal violet staining assay was used to analyze the biofilm formation in the wild-type (WT), ΔdsbA and CΔdsbA strains. V. cholerae strains containing msh promoter luxCDABE transcriptional fusion were used to analyze the transcriptional level.[Results] The ΔdsbA and CΔdsbA strains were constructed successfully. Biofilm formation analysis shows that the ability of biofilm formation of ΔdsbA was significantly reduced compared with WT, whereas CΔdsbA could form even stronger biofilm than WT does. Luminescence expression by Pmsh shows that VcDsbA enhanced msh expression. VcDsbA enhances the biofilm formation of V. cholerae by involving in the regulation of msh expression level. VcDsbA up-regulates msh expression probably through helping the folding of a msh expression activator.[Conclusion] VcDsbA plays an important role in the biofilm formation of V. chlerae, which makes the bacteria better survive in their living niche.

Key words:Vibrio cholerae;biofilm;VcDsbA;MSHA