ABSTRACT

Vibrio mimicus is a foodborne pathogen, which is widely distributed in the aquatic environment. Moreover, it is often involved in aquatic animal diseases. In recent years, V. mimicus is an emerging pathogen in some species of Siluriformes. The strain SCCF01 was isolated from yellow catfish (Pelteobagrus fulvidraco). In this study, we aimed to perform genomic analysis of V. mimicus strain SCCF01 to identify genetic features and evolutionary relationships. Information on gene function and classification was obtained by functional annotation, and circular graph of strain SCCF01 genome, which was created by Circos v0.64. Information on virulence genes (adhesion, flagellum system, exotoxin, and secretory system, etc.) was obtained by virulence genes annotation. Genome element prediction showed that most of the mobile elements were distributed in chromosome I. Therefore, chromosome I of SCCF01 genome has more plasticity than chromosome II and might be larger in size. Genomic linear relationship between the strain of V. mimicus and strain SCCF01 was analyzed by linear pairwise comparison but was unable to determine the relationship. Gene family analysis predicted that the evolutionary direction of strain SCCF01 was: clinical strain → environmental strain → SCCF01 strain. Phylogenetic analysis showed that the strain SCCF01 was more closely related to environmental strains. According to gene family analysis and phylogenetic analysis, we speculated that strain SCCF01 has probably diverged from environmental strains.

摘要

拟态弧菌是一种食源性病原体，广泛分布于水生环境中。而且，常常与水生动物疾病有关。近年来，拟态弧菌是鲶形目某些物种中新出现的病原体。菌株 SCCF01 是从黄颡鱼 ( Pelteobagrus fulvidraco ) 中分离出来的。在本研究中，我们旨在对拟态弧菌菌株 SCCF01进行基因组分析，以确定遗传特征和进化关系。通过功能注释和由Circos v0.64创建的菌株SCCF01基因组循环图获得基因功能和分类信息。通过毒力基因注释获得毒力基因信息（粘附、鞭毛系统、外毒素、分泌系统等）。基因组元件预测显示，大部分可移动元件分布在I号染色体上，因此SCCF01基因组的I号染色体比II号染色体具有更大的可塑性，并且尺寸可能更大。通过线性配对比较分析了拟态弧菌菌株和SCCF01菌株之间的基因组线性关系，但无法确定这种关系。基因家族分析预测菌株SCCF01的进化方向为：临床菌株→环境菌株→SCCF01菌株。系统发育分析表明菌株SCCF01与环境菌株的亲缘关系更为密切。根据基因家族分析和系统发育分析，我们推测SCCF01菌株可能与环境菌株发生了分化。