Mersni-Achour Rachida, Cheikh Yosra Ben, Pichereau Vianney, Doghri Ibtissem, Etien Cédric, Dégremont Lionel, Saulnier Denis, Fruitier-Arnaudin Ingrid, Travers Marie-Agnès
Fédération de Recherche en Environnement et Développement Durable, FR CNRS 3097, Université de La Rochelle, La Rochelle, France.
IFREMER, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins Avenue de Mus de Loup, 17390 La Tremblade, France.
Microbiology (Reading). 2015 May;161(Pt 5):997-1007. doi: 10.1099/mic.0.000058. Epub 2015 Feb 20.
Vibrio tubiashii is a marine pathogen isolated from larval and juvenile bivalve molluscs that causes bacillary necrosis. Recent studies demonstrated the isolation of this species in a French experimental hatchery/nursery affecting Crassostrea gigas spat in 2007. Here, using larvae of C. gigas as an interaction model, we showed that the French V. tubiashii is virulent to larvae and can cause bacillary necrosis symptoms with an LD50 of about 2.3 × 10(3) c.f.u. ml(-1) after 24 h. Moreover, complete or gel permeation HPLC fractionated extracellular products (ECPs) of this strain appeared toxic to larvae. MS-MS analysis of the different ECP fractions revealed the existence of an extracellular metalloprotease and other suspected virulence factors. This observation is also supported by the expression level of some potential virulence factors. The overall results suggest that the pathology caused by the French V. tubiashii in C. gigas oysters is caused by a group of toxic factors and not only the metalloprotease.
塔氏弧菌是一种从双壳贝类幼体和稚体中分离出的海洋病原体，可引发细菌性坏死。近期研究表明，2007年在法国一家实验性育苗场/养殖场中分离出了该物种，当时它对太平洋牡蛎稚贝造成了影响。在此，我们以太平洋牡蛎幼虫作为相互作用模型，发现法国的塔氏弧菌对幼虫具有毒性，在24小时后，其半数致死剂量约为2.3×10³ 菌落形成单位/毫升，可引发细菌性坏死症状。此外，该菌株经完整或凝胶渗透高效液相色谱分离的细胞外产物对幼虫具有毒性。对不同细胞外产物组分的质谱-质谱分析揭示了一种细胞外金属蛋白酶和其他疑似毒力因子的存在。这一观察结果也得到了一些潜在毒力因子表达水平的支持。总体结果表明，法国的塔氏弧菌在太平洋牡蛎中引发的病理变化是由一组毒性因子导致的，而不仅仅是金属蛋白酶。
