副溶血性弧菌在全球人类和动物中表现出严重的致病性。在这项研究中,进行了基因组测序和比较分析,以深入表征副溶血性弧菌菌株LC的毒力因子(VF)库,对虾凡纳滨对虾表现出显著的毒力。应变LC,有两个环状染色体和三个线性质粒,与31个公开可用的副溶血性弧菌基因组的平均核苷酸同一性≥98.14%,包括13、11和7只虾-,人类-,和非致病性菌株,分别。基于全基因组可有可无基因的系统发育分析,将14株虾致病性菌株中的11株和11株临床菌株中的7株分为两个不同的进化枝,表明宿主特异性致病性和辅助基因之间密切相关。VFDB数据库显示,150个LC的VFs主要与分泌系统有关,坚持,抗吞噬作用,趋化性,运动性,和铁的吸收,而没有典型致病基因pirA的同源物,pirB,tdh,和trh被检测到。四个基因,mshB,wbfT,wbfU,和wbtI,在两种类型的致病菌株中都被鉴定出,但在非病原体中不存在。值得注意的是,类似于Yen-Tc的独特集群,它编码一种杀虫毒素复合物,和不同的毒素-抗毒素(TA)系统,在LC的移动遗传元件(MGE)上鉴定。最后,除了常见的VF,各种独特的MGE承载的VF,包括Yen-Tc集群,TA组件,和多个染色体编码的几丁质酶基因,可能有助于LC毒力的全谱。此外,V.副溶血病表现出宿主特异性毒力,这可能会驱动致病因素的起源和传播。
Vibrio parahaemolyticus exhibits severe pathogenicity in humans and animals worldwide. In this study, genome sequencing and comparative analyses were conducted for in-depth characterization of the virulence factor (VF) repertoire of V. parahaemolyticus strain LC, which presented significant virulence to shrimp Litopenaeus vannamei. Strain LC, harboring two circular chromosomes and three linear plasmids, demonstrated ≥98.14% average nucleotide identities with 31 publicly available V. parahaemolyticus genomes, including 13, 11, and 7 shrimp-, human-, and non-pathogenic strains, respectively. Phylogeny analysis based on dispensable genes of pan-genome clustered 11 out of 14 shrimp-pathogenic strains and 7 out of 11 clinical strains into two distinct clades, indicating the close association between host-specific pathogenicity and accessory genes. The VFDB database revealed that 150 VFs of LC were mainly associated with the secretion system, adherence, antiphagocytosis, chemotaxis, motility, and iron uptake, whereas no homologs of the typical pathogenic genes pirA, pirB, tdh, and trh were detected. Four genes, mshB, wbfT, wbfU, and wbtI, were identified in both types of pathogenic strains but were absent in non-pathogens. Notably, a unique cluster similar to Yen-Tc, which encodes an insecticidal toxin complex, and diverse toxin-antitoxin (TA) systems, were identified on the mobile genetic elements (MGEs) of LC. Conclusively, in addition to the common VFs, various unique MGE-borne VFs, including the Yen-Tc cluster, TA components, and multiple chromosome-encoded chitinase genes, may contribute to the full spectrum of LC virulence. Moreover, V. parahaemolyticus demonstrates host-specific virulence, which potentially drives the origin and spread of pathogenic factors.