畜牧兽医学报 ›› 2016, Vol. 47 ›› Issue (1): 149-156.doi: 10.11843/j.issn.0366-6964.2016.01.020

• 预防兽医 • 上一篇    下一篇

猪源产新德里金属β-内酰胺酶-1大肠埃希菌的感染特性研究

常世恺1,赵战勤1*,薛云2,龙塔1,丁轲1,程相朝1   

  1. (1.河南科技大学动物科技学院,河南省高等学校环境与畜产品安全重点学科开放实验室,洛阳 471003;2.河南科技大学医学技术与工程学院,微生物检验实验室,洛阳 471003)
  • 收稿日期:2015-06-03 出版日期:2016-01-23 发布日期:2016-01-23
  • 通讯作者: 赵战勤(1980-),男,博士,副教授,E-mail:zhaozhanqin@126.com
  • 作者简介:常世恺(1989-),男,河南安阳人,硕士生,主要从事动物病原微生物学研究,E-mail:cskvip8@qq.com
  • 基金资助:

    国家自然科学基金项目(31302106);河南省科技攻关计划项目(132300410279)

Transmissibility of New Delhi Metallo-β-lactamase-1-Producing Escherichia coli Isolate from Pig

CHANG Shi-kai1,ZHAO Zhan-qin1* ,XUE Yun2,LONG Ta1,DING Ke1,CHENG Xiang-chao1   

  1. (1.Lab of Veterinary Microbiology,College of Animal Science and Technology,Henan University of Science and Technology,Luoyang 471003,China;2.Lab of Medical Engineering,College of Medical Technology and Engineering,Henan University of Science and Technology,Luoyang 471003,China)
  • Received:2015-06-03 Online:2016-01-23 Published:2016-01-23

摘要:

对猪源产NDM-1大肠埃希菌E120413株在猪群中的交互传播、致病力和体内分布特性等进行初步探讨。仔猪粪便样本的细菌学检测结果表明,E120413株细菌能从接种仔猪快速传染给未接种的同居组仔猪;接种组仔猪粪便样本检测到E120413株细菌的持续时间最短为7周,最长超过11周;同居组的持续时间介于7~9周。仔猪血液样本的检测结果表明,E120413株细菌能快速突破仔猪的免疫防御进入血液循环形成菌血症;接种组和同居组仔猪菌血症的持续时间为第2—10天和第4—10天,并在第7天达到最高活菌浓度3.7×105和4.3×105 CFU•mL-1。仔猪组织样本的检测结果表明,从感染仔猪的脑、心、肝、脾、肺、肾、胃、肠系膜淋巴结和十二指肠中均能分离到该菌,且能在十二指肠长期存在(≥11周)。但仔猪的临床症状与病理学检查结果表明,该菌仅能引起感染猪的体温升高和轻微的局部炎症反应,并不能导致猪的明显临床症状和严重病理变化。产NDM-1大肠埃希菌E120413株对猪具有较强的传播扩散能力和持续感染能力。

Abstract:

 One NDM-1-Producing Escherichia coli strain,designated as E120413,was isolated from a clinical pig case in China.Here we determined its transmissibility,pathogenicity and in vivo distribution in pigs.We performed kinetic bacterial distribution assays of porcine fecal samples,blood samples and organ tissues.The results demonstrated that E120413 strain can quickly infect the Close contacts of piglets from the inoculated piglets after being given 2 mL of the bacterial suspension containing 1.1×1010 CFU of E120413 strain.In these two groups,similar numbers of organisms were isolated from the fecal samples of these two groups of piglets,giving the longest persistence terms of over 11 weeks and 9 weeks,respectively.The E120413 organisms also could be isolated from the blood samples from day 2 to day 10 in the inoculated piglets and from day 4 to day 10 in the control piglets with the peaks of 3.7×105 and 4.3×105 CFU•mL-1 respectively,suggesting that the E120413 organisms might reach the porcine blood circulation and tissues effectively after infection.The presence of live E120413 organisms was then observed in brain,heart,liver,spleen,lung,kidney,stomach,duodenum,and mesenteric lymph nodes in both oral delivery group and control group.The stronger persistence of E120413 organisms in the mesenteric lymph nodes (≥11 weeks) may result from the environment,which was less hostile than that in any other organs of pig based on tissue specificity.But,no obvious signs of disease and serious pathological changes were observed in these two groups of pigs during the entire experimental period.In conclusion,we have shown that the NDM-1-Producing Escherichia coli E120413 strain has the stronger transmissibility and ability to cause persistent infection in pigs.

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