• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Infection and immunity >Pathogenicity of an Escherichia coli O115:K'V165' mutant negative for F165(1) fimbriae in septicemia of gnotobiotic pigs.
【24h】

Pathogenicity of an Escherichia coli O115:K'V165' mutant negative for F165(1) fimbriae in septicemia of gnotobiotic pigs.

机译：大肠埃希氏菌败血症中F165（1）菌毛阴性的大肠杆菌O115：K“ V165”突变体的致病性。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

To evaluate the role of the F165(1) fimbrial system in the pathogenesis of septicemia, 2-day-old germfree pigs were inoculated intragastrically with Escherichia coli O115:K"V165":F165 wild-type strain 5131, its F165(1)-negative TnphoA mutant M48, or E. coli O115:K(-):F165(-) wild-type strain 862B. Pigs were sacrificed at different times (3, 6, 12, 24, 48, and 96 h) postinfection (p.i.). Pigs inoculated with strain 5131 developed clinical signs (anorexia, lameness, reluctance to move, or lack of motor coordination) and were moribund within 48 h p.i., and, at necropsy, infecting bacteria were isolated in various extraintestinal organs. Strain 5131 was isolated as early as 6 h p.i. from the blood of inoculated pigs. Pigs inoculated with mutant M48 developed only mild clinical signs at 96 h p.i. Mutant M48 colonized extraintestinal organs of pigs but to a lesser extent than the parent strain did. In contrast to the parent strain, this mutant was not isolated in the blood of inoculated pigs. Pigs inoculated with strain 862B remained normal during the experiment. All of the strains colonized the mucus layer of the intestine, but no histological changes of intestinal mucosa were observed by either light or electron microscopy. The parent strain, but not the mutant M48, expressed F165(1) in vivo. In a competitive study in which the parent strain and its afimbrial mutant were inoculated simultaneously, clinical signs of septicemia developed 24 h after inoculation, and only the parent strain 5131 was isolated from the blood of inoculated pigs. Our results suggest that the F165(1) fimbrial system of E. coli O115:K"V165" strains may play an important role in the ability of the bacteria to survive in the blood and spread systemically through the porcine host.
机译：为了评估F165（1）纤维系统在败血病发病机理中的作用，用大肠杆菌O115：K“ V165”：F165野生型菌株5131对其胃内接种了2天大的无菌猪，其F165（1）阴性的TnphoA突变体M48，或大肠杆菌O115：K（-）：F165（-）野生型菌株862B。在感染后（p.i.）的不同时间（3、6、12、24、48和96 h）处死猪。接种5131株的猪出现临床体征（厌食，la行，不愿移动或缺乏运动协调），并在48 h内垂死，尸体剖检时在各种肠外器官中分离出感染细菌。早在6 h p.i分离出菌株5131。从接种猪的血液中提取。接种突变M48的猪在p.i时仅出现了轻度的临床体征。突变的M48定植在猪的肠外器官中，但程度低于亲本菌株。与亲本菌株相反，该突变体未在接种猪的血液中分离。在实验期间，接种862B株的猪保持正常。所有菌株都定殖在肠的粘液层，但是通过光学或电子显微镜未观察到肠粘膜的组织学变化。亲本菌株，但不是突变体M48，在体内表达F165（1）。在一项竞争研究中，同时接种了亲本菌株及其亲本突变体，接种后24小时出现了败血病的临床体征，仅从接种猪的血液中分离出了亲本5131。我们的结果表明，大肠杆菌O115：K“ V165”菌株的F165（1）纤维系统可能在细菌在血液中存活并通过猪宿主系统传播的能力中发挥重要作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号