Martinez Clara, Rodriguez Sergio, Vences Ana, Barja Juan L, Toranzo Alicia E, Dubert Javier
Department of Microbiology and Parasitology, Aquaculture Institute & CIBUS-Faculty of Biology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Microorganisms. 2022 Dec 15;10(12):2475. doi: 10.3390/microorganisms10122475.
is an emergent pathogen affecting clams, oysters and scallops produced in the most important countries for bivalve aquaculture. Studies concerning virulence factors involved in the virulence of are very scarce despite its global significance for aquaculture. Zinc-metalloproteases have been described as a major virulence factor in some spp., although their contribution and role in the virulence of is not clear. To address this, we have studied an extracellular zinc-metalloprotease (VemA) encoded by , which was identified as a vibriolysin, highly conserved in this species and homologous in other pathogenic and non-pathogenic species. Virulence challenge experiments demonstrated that infection processes were faster when Manila clam larvae and juveniles were infected with the wildtype rather than with a mutant defective in the gene (Δ). was able to resist the bactericidal action of mucus and displayed a chemotaxis ability favoured by VemA to colonize the body mucus of clams and form a biofilm. The overall results suggest that VemA, although it is not a major virulence factor, plays a role in the colonization of the Manila clam mucus, and thus boosts the infection process as we observed in virulence challenge experiments.
是一种新兴病原体，影响着双壳贝类水产养殖最重要国家所产的蛤蜊、牡蛎和扇贝。尽管其对水产养殖具有全球重要性，但关于其毒力相关毒力因子的研究非常稀少。锌金属蛋白酶在一些弧菌属物种中被描述为主要毒力因子，尽管它们在该弧菌毒力中的贡献和作用尚不清楚。为了解决这个问题，我们研究了由该弧菌编码的一种细胞外锌金属蛋白酶（VemA），它被鉴定为一种弧菌溶素，在该物种中高度保守，在其他致病和非致病物种中同源。毒力挑战实验表明，当用野生型而非该基因缺陷突变体（Δ）感染菲律宾蛤仔幼虫和幼体时，感染过程更快。该弧菌能够抵抗黏液的杀菌作用，并表现出受VemA促进的趋化能力，以定殖于蛤仔的体黏液并形成生物膜。总体结果表明，VemA虽然不是主要毒力因子，但在菲律宾蛤仔黏液的定殖中起作用，从而如我们在毒力挑战实验中观察到的那样促进感染过程。
