畜牧兽医学报 ›› 2021, Vol. 52 ›› Issue (4): 1053-1060.doi: 10.11843/j.issn.0366-6964.2021.04.020

• 预防兽医 • 上一篇    下一篇

双组分系统CpxR影响禽致病性大肠杆菌的耐药性、抗血清杀菌能力及毒力

易正飞1, 张耀东1, 王瑶1,2, 朱红1, 陶程琳1,3, AFAYIBO Dossêh Jean Apôtre1, 李涛1, 祁晶晶1, 田明星1, 丁铲1, 于圣青1*, 王少辉1*   

  1. 1. 中国农业科学院上海兽医研究所, 上海 200241;
    2. 西南民族大学生命科学与技术学院, 成都 610041;
    3. 扬州大学兽医学院, 扬州 225009
  • 收稿日期:2020-09-02 出版日期:2021-04-23 发布日期:2021-04-25
  • 通讯作者: 王少辉,主要从事畜禽细菌性传染病研究,Tel:021-34293412;E-mail:shwang0827@126.com;于圣青,主要从事畜禽细菌性传染病研究,Tel:021-34293461,E-mail:yus@shvri.ac.cn
  • 作者简介:易正飞(1992-),男,安徽马鞍山人,硕士,主要从事禽致病性大肠杆菌致病机制研究,E-mail:zhengfeiyi666@163.com
  • 基金资助:
    国家自然科学基金项目(31972654;31872483);上海市浦江人才计划项目(2019PJD057)

Two Component System CpxR Contributes to the Antibiotic Resistance, Serum Bactericidal Resistance and Virulence of Avian Pathogenic Escherichia coli

YI Zhengfei1, ZHANG Yaodong1, WANG Yao1,2, ZHU Hong1, TAO Chenglin1,3, AFAYIBO Dossêh Jean Apôtre1, LI Tao1, QI Jingjing1, TIAN Mingxing1, DING Chan1, YU Shengqing1*, WANG Shaohui1*   

  1. 1. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China;
    2. College of Life Science and Technology, Southwest Minzu University, Chengdu 610041, China;
    3. College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
  • Received:2020-09-02 Online:2021-04-23 Published:2021-04-25

摘要: CpxR是细菌中Cpx双组分系统(two component system,TCS)的反应调控蛋白,通过调控靶基因的转录表达,在细菌细胞膜稳定及毒力方面发挥作用。本研究旨在探究TCS CpxR对禽致病性大肠杆菌(avian pathogenic Escherichia coli,APEC)基本生物学特性、抗血清杀菌能力及致病性的影响。利用Red同源重组系统及互补质粒构建cpxR基因缺失株、互补株,然后比较分析野生株、基因缺失株与互补株的生长曲线、运动性、生物被膜形成能力、药物敏感性、抗血清杀菌能力、动物致病性的差异。结果显示:cpxR基因缺失株与野生株、互补株的生长速度和运动性能无明显差异,且缺失cpxR基因不影响APEC的生物被膜形成能力。然而,缺失CpxR导致APEC对阿米卡星和卡那霉素耐药性降低。血清杀菌试验结果显示,CpxR有助于APEC的抗血清杀菌能力。动物感染试验结果显示,野生株、cpxR基因缺失株和互补株对雏鸭的半数致死量(LD50)分别为7.50×105、7.50×106、1.33×106 CFU,表明CpxR缺失显著降低APEC的毒力。综上表明,TCS CpxR在APEC耐药性、抗血清杀菌能力及毒力方面发挥作用,为阐明APEC的环境适应性、生存能力及致病机制提供参考。

关键词: 禽致病性大肠杆菌, CpxR, 耐药性, 抗血清杀菌, 毒力

Abstract: CpxR is the response regulator of the Cpx two component system (TCS), which is involving in maintaining stability of membrane and virulence through regulating the transcriptional expression of target genes in bacteria. This study investigated the effects of TCS CpxR on the biological characteristics, serum bactericidal resistance and pathogenicity of avian pathogenic Escherichia coli (APEC). The cpxR gene mutant and complemented strains of APEC was constructed by Red homologous recombination system and complementation plasmid. Then, the growth curve, motility, biofilm formation, antibiotic sensitivity, serum bactericidal resistance, virulence among wild-type, cpxR mutant and complemented strains were compared and analyzed. There is no significant difference in growth rate and motility among wild-type, cpxR mutant and complemented strains. Moreover, CpxR did not affect the biofilm formation of APEC. However, the antibiotic sensitivity assays showed that cpxR mutant was less resistant to amikacin and kanamycin. The results indicated that of CpxR could enhance the survival ability of APEC in serum. Animal infection experiment showed that the median lethal dose (LD50) of wild-type, cpxR mutant and complemented strains were 7.50×105, 7.50×106 and 1.33×106 CFU respectively, indicating that cpxR mutant strain exhibited attenuated virulence in ducks. These data indicated that TCS CpxR contributes to the antibiotic resistance, serum bactericidal resistance and virulence of APEC, providing help for elucidating the environment adaptability, survival ability and pathogenic mechanism of APEC.

Key words: avian pathogenic Escherichia coli, CpxR, antibiotic resistance, serum bactericidal resistance, virulence

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