Vibriosis has been implicated in major losses of larvae at shellfish hatcheries. However, the species of Vibrio responsible for disease in aquaculture settings and their associated virulence genes are often variable or undefined. Knowledge of the specific nature of these factors is essential to developing a better understanding of the environmental and biological conditions that lead to larvae mortality events in hatcheries. We tested the virulence of 51 Vibrio strains towards Pacific Oyster (Crassostreae gigas) larvae and sequenced draft genomes of 42 hatchery-associated vibrios to determine groups of orthologous genes associated with virulence and to determine the phylogenetic relationships among pathogens and non-pathogens of C. gigas larvae. V. coralliilyticus strains were the most prevalent pathogenic isolates. A phylogenetic logistic regression model identified over 500 protein-coding genes correlated with pathogenicity. Many of these genes had straightforward links to disease mechanisms, including predicted hemolysins, proteases, and multiple Type 3 Secretion System genes, while others appear to have possible indirect roles in pathogenesis and may be more important for general survival in the host environment. Multiple metabolism and nutrient acquisition genes were also identified to correlate with pathogenicity, highlighting specific features that may enable pathogen survival within C. gigas larvae. These findings have important implications on the range of pathogenic Vibrio spp. found in oyster-rearing environments and the genetic determinants of virulence in these populations.

中文翻译：

---

弧菌的比较基因组分析可深入了解与巨球藻幼虫毒性相关的基因。

弧菌病与贝类孵化场中幼虫的大量损失有关。然而，在水产养殖环境中引起疾病​​的弧菌种类及其相关的毒力基因通常是可变的或不确定的。了解这些因素的具体性质对于更好地理解导致孵化场中幼虫死亡的环境和生物学条件至关重要。我们测试了51种弧菌对太平洋牡蛎（Crassostreae gigas）幼虫的毒力，并测序了42个孵化场相关弧菌的基因组草图，以确定与毒力相关的直系同源基因组，并确定了C病原体和非病原体之间的系统发生关系。吉加斯幼虫。V.coralliilyticus菌株是最流行的病原菌。系统发育逻辑回归模型确定了超过500个与致病性相关的蛋白质编码基因。这些基因中的许多与疾病机制直接相关，包括预测的溶血素，蛋白酶和多个3型分泌系统基因，而其他一些似乎在发病中可能具有间接作用，并且对于宿主环境中的一般存活可能更为重要。还确定了多种代谢和养分获取基因与致病性相关，突出了可能使病原体在巨球藻幼虫中存活的特定特征。这些发现对致病性弧菌的范围具有重要意义。在牡蛎育种环境中发现，以及这些人群中毒力的遗传决定因素。