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中国农学通报 ›› 2021, Vol. 37 ›› Issue (20): 152-159.doi: 10.11924/j.issn.1000-6850.casb2020-0484

所属专题: 生物技术 水产渔业

• 水产·渔业 • 上一篇    下一篇

一株中华鳖源嗜水气单胞菌的分离鉴定及毒力基因分析

薛明洋1(), 周勇1, 梁宏伟1, 李翔2, 范玉顶1, 曾令兵1, 曲春娟3, 孟彦1()   

  1. 1中国水产科学研究院长江水产研究所,武汉 430223
    2安徽省喜佳农业技术有限公司,安徽蚌埠 233000
    3安徽省蚌埠市水产技术推广中心,安徽蚌埠 233000
  • 收稿日期:2020-09-22 修回日期:2021-01-21 出版日期:2021-07-15 发布日期:2021-08-06
  • 通讯作者: 孟彦
  • 作者简介:薛明洋,男,1991年出生,湖北十堰人,研究实习员,硕士,研究方向为水生动物病害防治。通信地址:430223 湖北省武汉市东湖新技术开发区武大园一路8号 中国水产科学研究院长江水产研究所,Tel:027-81785198,E-mail:xmy@yfi.ac.cn
  • 基金资助:
    国家“淡水水产种质资源库”(FGRC18537)

Isolation, Identification and Virulence Gene Analysis of an Aeromonas hydrophila from Diseased Pelodiscus sinensis

Xue Mingyang1(), Zhou Yong1, Liang Hongwei1, Li Xiang2, Fan Yuding1, Zeng Lingbing1, Qu Chunjuan3, Meng Yan1()   

  1. 1Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223
    2Anhui XiJia Agricultural Technology Co., LTD., Anhui Bengbu 233000
    3Bengbu Aquatic Technology Promotion Station, Anhui Bengbu 233000
  • Received:2020-09-22 Revised:2021-01-21 Online:2021-07-15 Published:2021-08-06
  • Contact: Meng Yan

摘要:

为了确定安徽某中华鳖养殖场导致中华鳖发病的病原,为今后生产中有效防控该疾病提供参考。本研究无菌条件下从患病中华鳖体内分离病原,通过形态学、生理生化特征和16SrDNA序列分析对病原菌进行鉴定;利用回归感染试验对病原菌致病性进行确定,采用琼脂扩散法进行药敏试验,并对病原的毒力基因进行分析。结果从患病中华鳖体内分离纯化得到一株致病菌,命名为AM-1,经鉴定该菌为嗜水气单胞菌(Aeromonas hydrophila);用该菌进行人工感染得到的症状与自然发病中华鳖症状一致;该菌对恩诺沙星和左氧氟沙星等药物敏感,对复方新诺明、氨苄西林和四环素等不敏感。毒力基因检测显示,该嗜水气单胞菌AM-1分离株携带气溶素、热不稳定性肠毒素、热稳定性肠毒素、溶血素、弹性蛋白酶5种毒力基因。最终表明嗜水气单胞菌AM-1是引起此次中华鳖发病的病原,可以使用恩诺沙星和左氧氟沙星等药物进行防治。

关键词: 中华鳖, 嗜水气单胞菌, 毒力基因, 致病性

Abstract:

The study aims to determine the pathogen causing disease in a Chinese soft-shelled turtle farm in Anhui Province, and provide reference for effective prevention and control of the disease in future production. The pathogenic bacteria were isolated from the moribund turtle with typical symptoms under aseptic condition, and then were identified by the morphological examination, biochemical analysis, and sequence analysis of bacterial 16S rDNA. The drug susceptibility test was conducted by Kirby-Bauer agar diffusion method, and the virulence genes of the pathogen were analyzed. The results showed that the pathogen was identified as Aeromonas hydrophila, called AM-1. Artificial infection showed that the typical symptoms of the disease could be replicated as the ones naturally occurred and this bacterium was of high pathogenicity to Chinese soft-shelled turtle. The drug resistance tests showed that the isolated pathogen was highly sensitive to enrofloxacin and levofloxacin, while extremely resistant to cotrimoxazole, ampicillin and tetracycline. The amplification results of 6 virulence genes showed that the isolated pathogen carried 5 virulence genes including aerolysin, heat-labile enterotoxin, heat-stable enterotoxin, hemolysin and elastase. This study indicates that Aeromonas hydrophila AM-1 is the pathogenic bacteria which could cause the deadly disease outbreak of the Chinese turtle. Enrofloxacin and levofloxacin can be used for treatment.

Key words: Pelodiscus sinensis, Aeromonas hydrophila, virulence gene, pathogenicity

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