Liu Peng-Xuan, Zhang Xiao-Yun, Wang Quan, Li Yang-Yang, Sun Wei-Dong, Qi Yu, Zhou Kai, Han Xian-Gan, Chen Zhao-Guo, Fang Wei-Huan, Jiang Wei
Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Front Microbiol. 2022 Aug 9;13:976334. doi: 10.3389/fmicb.2022.976334. eCollection 2022.
is a marine pathogen thought to be the leading cause of seafood-borne gastroenteritis globally, urgently requiring efficient management methods. encodes 12 resistance/nodulation/division (RND) efflux systems. However, research on these systems is still in its infancy. In this study, we discovered that the inactivation of VmeL, a membrane fusion protein within the RND efflux systems, led to reduction of the ability of biofilm formation. Further results displayed that the decreased capacity of Congo red binding and the colony of Δ is more translucent compared with wild type strains, suggested reduced biofilm formation due to decreased production of biofilm exopolysaccharide upon deletion. In addition, the deletion of abolished surface swarming and swimming motility of . Additionally, deletion of weakened the cytotoxicity of towards HeLa cells, and impaired its virulence in a murine intraperitoneal infection assay. Finally, through RNA-sequencing, we ascertained that there were 716 upregulated genes and 247 downregulated genes in Δ strain. KEGG enrichment analysis revealed that quorum sensing, bacterial secretion systems, ATP-binding cassette transporters, and various amino acid metabolism pathways were altered due to the inactivation of . qRT-PCR further confirmed that genes accountable to the type III secretion system (T3SS1) and lateral flagella were negatively affected by deletion. Taken together, our results suggest that VmeL plays an important role in pathogenicity, making it a good target for managing infection with
是一种海洋病原体，被认为是全球食源性肠胃炎的主要病因，迫切需要有效的管理方法。它编码12种抗性/结瘤/分裂（RND）外排系统。然而，对这些系统的研究仍处于起步阶段。在本研究中，我们发现RND外排系统中的膜融合蛋白VmeL失活导致生物膜形成能力下降。进一步的结果表明，刚果红结合能力降低，与野生型菌株相比，Δ的菌落更透明，这表明由于缺失后生物膜胞外多糖产量降低导致生物膜形成减少。此外，的缺失消除了的表面群游和游动运动性。另外，的缺失减弱了对HeLa细胞的细胞毒性，并在小鼠腹腔感染试验中损害了其毒力。最后，通过RNA测序，我们确定在Δ菌株中有716个上调基因和247个下调基因。KEGG富集分析表明，由于的失活，群体感应、细菌分泌系统、ATP结合盒转运蛋白和各种氨基酸代谢途径发生了改变。qRT-PCR进一步证实，负责III型分泌系统（T3SS1）和侧鞭毛的基因受到缺失的负面影响。综上所述，我们的结果表明VmeL在致病性中起重要作用，使其成为管理感染的良好靶点。
