中国畜牧兽医 ›› 2022, Vol. 49 ›› Issue (5): 1977-1984.doi: 10.16431/j.cnki.1671-7236.2022.05.039

• 预防兽医 • 上一篇    下一篇

鸭源大肠杆菌的分离鉴定及致病性分析

董洪燕1, 宋海港2, 朱善元1, 于圣青3, 谢军1, 洪双鹏1, 郭长明1, 徐海1, 高月秀1   

  1. 1. 江苏农牧科技职业学院, 泰州 225300;
    2. 扬州大学兽医学院, 扬州 225009;
    3. 中国农业科学院上海兽医研究所, 上海 200241
  • 收稿日期:2021-11-07 出版日期:2022-05-05 发布日期:2022-04-29
  • 通讯作者: 朱善元, 于圣青 E-mail:jstzzsy@126.com;yus@shvri.ac.cn
  • 作者简介:董洪燕,E-mail:56770779@qq.com。
  • 基金资助:
    江苏省农业科技自主创新资金项目(CX(18)1004);江苏现代农业产业技术体系集成创新中心(JATS[2020]345);江苏省高等学校自然科学研究重大项目(20KJA230004);江苏农牧科技职业学院院级课题(NSF201902);2020年大学生创新创业训练计划项目(202012806078Y);泰州市农业支撑项目(TN201917)

Isolation,Identification and Pathogenicity Analysis of Escherichia coli from Ducks

DONG Hongyan1, SONG Haigang2, ZHU Shanyuan1, YU Shengqing3, XIE Jun1, HONG Shuangpeng1, GUO Changming1, XU Hai1, GAO Yuexiu1   

  1. 1. Jiangsu Agri-animal Husbandry Vocational College, Taizhou 225300, China;
    2. College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China;
    3. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
  • Received:2021-11-07 Online:2022-05-05 Published:2022-04-29

摘要: 【目的】 了解江苏、江西、安徽地区鸭源大肠杆菌的分布以及致病性情况。【方法】 本研究对江苏、江西、安徽地区的病死鸭进行了鸭源大肠杆菌的分离鉴定,运用PCR结合玻片凝集法测定鸭源大肠杆菌分离株的血清型,并进行了18种毒力基因的PCR检测,随后进行雏鸭致病性试验,并对毒力较强和毒力较弱的菌株进行生长曲线以及半数致死量(LD50)测定。【结果】 本研究共分离鉴定获得鸭源大肠杆菌74株,鉴定为O1、O2、O18、O78血清型的分别有1、2、2和4株,其余均未定型;18种毒力基因鉴定结果表明,ibeB、yijp、OmpAmat基因检出率分别为97.3%、97.3%、95.95%和90.54%。动物致病性试验结果表明,经107 CFU/只攻毒后,74株分离株均引起雏鸭不同程度发病,但仅有2株对雏鸭致死率≥50%。生长曲线测定结果表明,2株强毒株与2株弱毒株的生长速度无显著差异(P>0.05),2株强毒株的LD50分别为104.75和107.375 CFU。【结论】 本研究分离的74株鸭源大肠杆菌O1、O2、O18和O78型仅占12.16%,毒力基因谱分布广泛,但仅有2株毒力较强,该研究为鸭源大肠杆菌病的预防控制以及研究血清型、毒力基因与致病性之间的相互关系奠定基础。

关键词: 鸭源大肠杆菌; 血清型; 毒力基因; 动物致病性试验

Abstract: 【Objective】 This study was aimed to understand the distribution and pathogenicity of Escherichia coli from ducks in Jiangsu,Jiangxi and Anhui provinces.【Method】 This study isolated and identified duck derived Escherichia coli from dead ducks in Jiangsu,Jiangxi and Anhui,determined the serotype of duck derived Escherichia coli isolates by PCR combined with slide agglutination,detected 18 virulence genes by PCR,and then carried out the pathogenicity test of ducklings.The growth curve and median lethal dose (LD50) of the strains with strong and weak virulence were determined.【Result】 A total of 74 strains of duck derived Escherichia coli were isolated and identified in this study,1,2,2 and 4 strains were identified as O1,O2,O18 and O78 serotypes respectively,and the rest were not finalized.The identification test of 18 virulence genes showed that positive rates of genes ibeB,yijp,ompA and mat were 97.3%,97.3%,95.95% and 90.54%,respectively.Animal pathogenicity tests showed that 74 strains of Escherichia coli isolates were pathogenic to ducklings at infection dose of 107 CFU/duck,but only 2 strains of isolates caused the death rate of ducklings ≥50%.The growth curve detemination showed that there was no significant difference between 2 strains of virulent isolates and 2 strains of attenuated isolates (P>0.05),and the LD50 of 2 strains of virulent isolates were 104.75and 107.375 CFU,respectively.【Conclusion】 The rate of serotypes O1,O2,O18,O78 in 74 isolates was only 12.16%.The virulence gene spectrum was widely distributed,but only 2 strains of isolates were more virulent.This study laid the foundation for the prevention and control of Escherichia coli from ducks,it was also helpful for studying the relationship among serotypes,virulence genes and pathogenicity.

Key words: Escherichia coli from ducks; serotypes; virulence genes; animal pathogenicity test

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