鲫源迟缓爱德华氏菌的分离鉴定及其毒力基因的检测

发布时间：2018-11-11 00:59

【摘要】：【目的】探明上海某养殖场的异育银鲫(Carassius auratus gibelio)发生死亡的病因,研究致病菌分类地位和毒力基因携带情况。【方法】通过病原菌的筛查和回感试验,确定发病原因,对16S rRNA基因、gyrB和rpoB管家基因测序,建立病原菌系统进化树,结合API-32E细菌鉴定系统对菌株的生理生化进行鉴定,综合判定致病菌的种类及其分类地位;根据已报道的7个毒力基因fimA、citC、gadB、mukF、katB、esrB和sodB序列,设计引物进行PCR扩增,研究病原菌毒力基因携带情况。【结果】致病菌GY15是导致异育银鲫发病的原因,GY15的16S rRNA、gyrB和rpoB基因与已报道的迟缓爱德华氏菌(Edwardsiella tarda)相似性在99%以上,构建系统进化树和API鉴定确定该菌株为E.tarda,腹腔注射回感可导致异育银鲫死亡,半致死浓度(LD_(50))为4.26×105 CFU/m L;已报道的7种毒力基因在该致病菌中均能被检测到;药敏试验结果显示,该菌对恩诺沙星、氟苯尼考和氧氟沙星等15种药物敏感,对新霉素、四环素和复方新诺明等18种药物表现为耐药。【结论】首次报道E.tarda可感染异育银鲫,它对异育银鲫的养殖造成威胁。
[Abstract]:[objective] to investigate the etiology of (Carassius auratus gibelio) death in a breeding farm in Shanghai, and to study the taxonomic status of pathogenic bacteria and the carrying of virulence genes. The 16s rRNA gene, gyrB and rpoB housekeeper gene were sequenced, and the phylogenetic tree of pathogenic bacteria was established. The physiological and biochemical identification of the strains was carried out by combining with the API-32E bacterial identification system, and the species of pathogenic bacteria and their taxonomic status were comprehensively determined. According to the reported fimA,citC,gadB,mukF,katB,esrB and sodB sequences of 7 virulence genes, primers were designed to amplify the virulence genes of pathogenic bacteria. [results] the pathogenic bacteria GY15 was the cause of the development of allogeneic crucian carp. The similarity between the 16s rRNA,gyrB and rpoB genes of GY15 and the reported (Edwardsiella tarda) was over 99%. The phylogenetic tree was constructed and API identified the strain as E. tarda.Intraperitoneal injection of resense resulted in the death of allogynogenetic crucian carp. The half-lethal concentration (LD_ (50) was 4.26 脳 10 ~ 5 CFU/m / L; Seven virulence genes were detected in the pathogen. The drug sensitivity test showed that the strain was sensitive to enrofloxacin, florfenicol and ofloxacin, and was sensitive to neomycin. Tetracycline and compound sulfamide showed resistance to drugs. [conclusion] E.tarda can infect allogeneic crucian carp for the first time, which poses a threat to the breeding of allogynogenetic crucian carp.
【作者单位】：上海海洋大学水产与生命学院;中国水产科学院黄海水产研究所;
【基金】：公益性行业(农业)科研专项项目(No.201203085) 国家水产种质资源平台项目上海海洋大学知识服务平台项目~~
【分类号】：S943

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