Gene deletion and functional analysis of vp2918 gene in Vibrio parahemolyticus

Abstract:

[Objective] By using comparative proteomics, we identified several potential T6SS-2 effectors, including VP2918. The aim of this study is to elucidate the role of VP2918 in biological characteristics and pathogenicity of Vibrio parahaemolyticus. [Methods] The vp2918 gene deletion mutant strain (Δvp2918) and complementary strain (CΔvp2918) were constructed via homologous recombination technology. Subsequently, the growth characteristics, biofilm formation ability, motility, adhesion and cytotoxicity to HeLa cells, and mice lethality rate, bacterial colonization were analyzed in the wild-type strain (WT), Δvp2918 and CΔvp2918. [Results] The biological characteristics analysis in vitro showed that there was no significant difference in growth curve, motility, biofilm formation ability and adhesion ability to HeLa cells among WT, Δvp2918 and CΔvp2918. However, compared with WT, the toxicity of Δvp2918 to HeLa cells was significantly weakened. Animal experimental results showed that compared with the mice infected with WT, the mice infected with Δvp2918 showed slighter symptoms and higher survival rate. The bacterial loads of Δvp2918 were significantly lower than that of WT in spleen and liver of infected mice, whereas the complementation strain restored the virulence to resemble that of WT. [Conclusion] The VP2918 was not associated with the motility and biofilm formation ability, but it was a potential virulence factor and associated with the pathogenic of V. parahaemolyticus.

Key words:Vibrio parahaemolyticus;vp2918;gene mutant;biological characteristics;pathogenicity