Tad型菌毛促胰液素CpaC对副溶血弧菌的运动性、生物被膜形成及致病性的影响

The Tad pilus secretin CpaC is associated with motility, biofilm formation, and pathogenicity of Vibrio parahaemolyticus

摘要:

目的 Tad菌毛广泛分布于革兰氏阴性菌，与多种病原体的毒力相关。目前，关于副溶血弧菌Tad菌毛的研究极少。本研究旨在揭示Tad菌毛促胰液素CpaC (VP2419)对副溶血弧菌生物学功能的影响。方法 以副溶血弧菌野生株SH112为基础，构建cpaC基因缺失株(ΔcpaC)及互补株(CΔcpaC)，比较各菌株的生物被膜形成能力、细菌竞争力、集群与泳动能力、细胞黏附与毒性、小鼠毒力、组织定殖及病变情况的差异。结果 在细菌环境适应方面，与野生株(WT株)相比，缺失株ΔcpaC的细菌竞争力、运动性和生物被膜形成能力均显著下降。在致病性方面，缺失株ΔcpaC在细胞黏附、细胞毒性，以及小鼠毒力、组织定殖和病变程度上较WT株均显著降低。结论 CpaC作为副溶血弧菌Tad菌毛的组分，参与多种关于环境适应与致病性的功能，包括竞争能力、生物被膜形成、运动性，以及细胞黏附与毒性、组织定殖等，为深入理解Tad菌毛的生物学功能提供了重要依据。

Abstract:

Objective Tad pili are widely distributed in Gram-negative bacteria and are associated with the virulence of various pathogens. However, the studies about the Tad pili in Vibrio parahaemolyticus remain limited. This study aimed to elucidate the role of the Tad pilus secretin CpaC (VP2419) in the biological functions of V. parahaemolyticus.Methods The cpaC-deleted mutant (ΔcpaC) and complemented strain (CΔcpaC) were constructed from the wild-type (WT) strain (SH112) of V. parahaemolyticus. The strains were compared in terms of biofilm formation, competitiveness, swarming and swimming motility, cell adhesion, cytotoxicity, as well as virulence, tissue colonization, and pathology in mice.Results Regarding environmental adaptation, compared with the WT strain, ΔcpaC exhibited significantly decreased competitiveness, motility, and biofilm formation. In terms of pathogenicity, ΔcpaC demonstrated significantly reduced cell adhesion, cytotoxicity, as well as attenuated virulence, tissue colonization, and pathological damage in mice, compared with the WT strain.Conclusion As the Tad pilus secretin in V. parahaemolyticus, CpaC participates in multiple functions related to environmental adaptation and pathogenicity, including competitiveness, biofilm formation, motility, cell adhesion, cytotoxicity, and tissue colonization. These findings provide important insights for a deeper understanding of the biological functions of Tad pili.