中国畜牧兽医 ›› 2020, Vol. 47 ›› Issue (3): 902-910.doi: 10.16431/j.cnki.1671-7236.2020.03.030

• 基础兽医 • 上一篇    下一篇

牛源大肠杆菌对秀丽隐杆线虫的致病性研究

白慧丽1, 彭昊2,3, 李军2,3, 李常挺2,3, 陶立2,3, 陈忠伟2,3, 吴翠兰2,3, 潘艳2,3, 曾芸1, 龚俞4   

  1. 1. 广西大学动物科学技术学院, 南宁 530004;
    2. 广西兽医研究所, 南宁 530001;
    3. 广西兽医生物技术重点实验室, 南宁 530001;
    4. 贵州省畜禽遗传资源管理站, 贵阳 550001
  • 收稿日期:2019-08-15 出版日期:2020-03-20 发布日期:2020-03-17
  • 通讯作者: 李军, 曾芸 E-mail:jlee9981@163.com;yzeng323@163.com
  • 作者简介:白慧丽(1994-),女,河南周口人,硕士生,研究方向:兽医药理与毒理学,E-mail:1305163227@qq.com;彭昊(1980-),男,湖南永顺人,博士,高级兽医师,研究方向:动物疫病防控与病原分子生物学,E-mail:hpeng2006@163.com
  • 基金资助:
    广西科技重大专项(桂科AA18118051);广西重点研发计划(桂科AB16380106、桂科AB18221074);桂科专项(18-3、19-3);国家现代农业产业体系广西肉牛肉羊产业创新团队建设(nycytxgxcxtd-09-05);贵州省科技攻关项目(黔科合NY[2015]3004-3号)

Study on the Pathogenicity of Escherichia coli from Cattle to Caenorhabditis elegans

BAI Huili1, PENG Hao2,3, LI Jun2,3, LI Changting2,3, TAO Li2,3, CHEN Zhongwei2,3, WU Cuilan2,3, PAN Yan2,3, ZENG Yun1, GONG Yu4   

  1. 1. College of Animal Science and Technology, Guangxi University, Nanning 530004, China;
    2. Guangxi Veterinary Research Institute, Nanning 530001, China;
    3. Guangxi Key Laboratory of Veterinary Biotechnology, Nanning 530001, China;
    4. Animal Science and Technology Station of Guizhou, Guiyang 550001, China
  • Received:2019-08-15 Online:2020-03-20 Published:2020-03-17

摘要: 为建立牛源大肠杆菌-秀丽隐杆线虫致病模型,本研究从广西南宁、桂林、柳州等地区收集的牛病料中分离出13株大肠杆菌,继而对这些大肠杆菌进行血清学鉴定及小鼠、秀丽隐杆线虫的致病性试验。采用玻片凝集法鉴定大肠杆菌的O血清型,并将13株大肠杆菌培养液以3.0×109 CFU/mL、0.2 mL/10 g体重给小鼠腹腔注射,同时分别喂食N2野生型秀丽隐杆线虫。结果显示,大肠杆菌的O血清型为O127、O126和O44,其中O126为优势血清型(4/13)。致病性结果显示,有11株大肠杆菌能使小鼠致死(致死率为40%~100%),2株大肠杆菌对小鼠没有致死性(致死率为0)。对小鼠有强致病性的大肠杆菌,对线虫的致死率也较高,死亡率在第3~6天最为显著,半数致死时间为3~4.5 d,最长存活时间为9 d;对小鼠不致死的两株大肠杆菌对线虫的致死率也较低,线虫死亡率下降趋势缓慢,半数致死时间为5~6 d,最长存活时间为10~11 d。肠道细菌计数结果显示,大肠杆菌在线虫体内的数量与时间呈线性关系,大肠杆菌不断破坏线虫的免疫系统,从而导致了线虫的死亡。本研究结果表明,大肠杆菌对线虫和小鼠的致病力试验结果一致,说明成功建立了牛源大肠杆菌-秀丽隐杆线虫致病模型,为牛病防治与临床用药提供了依据。

关键词: 牛; 大肠杆菌; 秀丽隐杆线虫; 小鼠; 致病性

Abstract: In order to study the pathogenicity of Escherichia coli (E.coli)to Caenorhabditis elegans (C.elegans),13 strains of E.coli were isolated from cattle disease materials collected in Nanning,Guilin,Liuzhou and Guangxi in this study.Then,the E. coli were subjected to serological identification,mouse pathogenicity test and C.elegans pathogenicity test.The O serotype of E.coli were identified by slide agglutination and the 13 E.coli bacterial liquids were intraperitoneally injected into the mice at a concentration of 3.0×109 CFU/mL and 0.2 mL/(10 g·BW).At the same time,these 13 strains of E. coli were infected with N2 wild type C.elegans.The results showed that the O serotypes of these E. coli were O127,O126 and O44,of which O126 was the dominant serotype (4/13).The pathogenicity results showed that 11 strains of E. coli could kill mice (40% to 100%),and 2 strains of E. coli were not lethal to mice (the mortality rates were 0). E.coli,which had strong pathogenicity to mice,also had a high lethal rate to nematodes,and the mortality rate were most significant on the 3rd to 6th day.The median lethal time was 3 to 4.5 d,and the longest survival time was 9 d.Two strains of E.coli which were not lethal to mice also had a low lethal rate to nematodes,the mortality of nematodes decreased slowly,the half lethal time was 5 to 6 d,and the longest survival time was 10 to 11 d.The results of intestinal bacterial count showed that the number of E.coli in the worm was linear with time,and E.coli constantly destroyed the nematode's immune system,which led to the death of nematodes.The results of this study indicated that the pathogenicity test of E.coli was consistent with the results of mouse pathogenicity test,indicating that the pathogenic model of E.coli-C.elegans was successfully established and laid the theoretical foundation for prevention and clinical use of bovine disease.

Key words: bovine; Escherichia coli; Caenorhabditis elegans; mouse; pathogenicity

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