黄颡鱼源致病性嗜水气单胞菌A01的分离鉴定、全基因组特征及比较基因分析  

Isolation,Identification,Whole-genome Characterization,and Comparative Genomic Analysis of Pathogenic Aeromonas hydrophila A01 from Pelteobagrus fulvidraco

作　　者：高玮 邵玲 GAO Wei;SHAO Ling(Shanghai Fisheries Research Institute/Shanghai Fisheries Technical Extension Station,Shanghai 200433,China)

机构地区：[1]上海市水产研究所/上海市水产技术推广站,上海200433

出　　处：《广东农业科学》2025年第2期82-94,共13页Guangdong Agricultural Sciences

基　　金：上海市农业科技创新项目(沪农科[T2024205]);上海市青年科技启明星计划(21QA1408300);上海市自然科学基金(21ZR1457800)。

摘　　要：[目的]解析从上海市某规模化养殖场患病黄颡鱼(Pelteobagrus fulvidraco)肝脏分离的致病性嗜水气单胞菌(Aeromonas hydrophila)的基因组特征、毒力及耐药基因水平,为病原学研究以及疾病防治提供理论支持。[方法]从患病黄颡鱼体内分离纯化菌株,通过形态学、生理生化特征等对分离菌进行鉴定。采用Illumina测序平台对分离菌株A01进行全基因组测序,利用SPAdes完成基因组组装、Prokka进行基因预测,并通过KEGG、GO、COG数据库进行功能注释。毒力基因与耐药基因分别通过VFDB和CARD/AMRFinderPlus数据库进行鉴定。通过ANI分析及基于直系同源单拷贝基因构建系统发育树,评估菌株间的亲缘关系,同时利用多位点序列分型(MLST)解析遗传背景。通过PCR和药敏试验检测菌株毒力基因及耐药性。[结果]黄颡鱼致病菌A01为嗜水气单胞菌,其基因组为环状,长约4.93 Mb,GC含量为61.09%,编码4 500个蛋白质基因、121个tRNA及3个rRNA基因。功能注释显示,其基因主要参与碳水化合物代谢、氨基酸代谢及膜转运等通路,提示其具有较强的环境适应能力。毒力基因分析共鉴定出527个毒力相关基因,包括鞭毛组装、趋化性及分泌系统基因,表明A01具有高侵袭性及宿主致病能力。耐药基因分析鉴定出279个耐药基因,涵盖β-内酰胺类、四环素类、氨基糖苷类及多黏菌素等抗生素种类,显示其多重耐药风险显著高于参考菌株ATCC7966。ANI分析(>96%)及系统发育树证实A01与ATCC7966亲缘关系最近。MLST分型提示遗传分化可能与致病性及耐药性差异相关。A01携带9个重要毒力基因(aer、act、fla、lip、gcaT、exu、ast、alt和ahyB),具有较强的致病性。药敏试验表明A01对24种抗生素中的16种表现多重耐药(MDR)。[结论]通过对分离鉴定的黄颡鱼源嗜水气单胞菌A01株开展全基因组分析,揭示其基因组基本特征和毒力及耐药基因水平,为后续深入开【Objective】This study aims to investigate the genomic characteristics,virulence,and drug resistance of a pathogenic Aeromonas hydrophila strain isolated from the liver of a diseased Pelteobagrus fulvidraco from a large aquaculture farm in Shanghai.This analysis seeks to provide theoretical insights into the etiology,prevention,and control of the disease.【Method】Bacterial strains were isolated and purified bacterial strains from the affected fish,and their identification was based on morphological,physiological,and biochemical traits.PCR detection for virulence genes and drug sensitivity tests were conducted.Strain A01 underwent whole-genome sequencing using the Illumina platform,followed by genome assembly with SPAdes,gene prediction via Prokka,and functional annotation through KEGG,GO,and COG databases.The VFDB and CARD/AMRFinderPlus databases facilitated the identification of virulence and resistance genes,respectively.Strain affinities were evaluated through ANI analysis and phylogenetic tree construction based on homologous single-copy genes,complemented by multilocus sequence typing(MLST)to discern genetic backgrounds.【Result】The pathogenic bacterium A01 of P.fulvidraco is A.hydrophila,with a circular genome of approximately 4.93 Mb in length and a GC content of 61.09%.It encodes 4500 protein genes,121 tRNAs,and 3 rRNAs.Functional annotation highlighted its genes were involved in carbohydrate metabolism,amino acid metabolism,and membrane transport,suggesting strong environmental adaptability.Analysis uncovered 527 virulence-related genes,encompassing flagellar assembly,chemotaxis,and secretion system genes,pointing to A01’s high invasiveness and pathogenicity.Additionally,279 resistance genes were identified,including antibiotics such asβ-lactams,tetracyclines,aminoglycosides,and polymyxins,indicating a significantly higher MDR risk compared to the reference strain ATCC7966.ANI analysis(>96%)and phylogenetic trees confirmed A01 was closely related to ATCC7966,while MLST typing hinted at a poss

关 键 词：黄颡鱼 嗜水气单胞菌 全基因组测序 毒力基因 耐药基因 比较基因组学 

分 类 号：S943[农业科学—水产养殖]