中国农业科学 ›› 2012, Vol. 45 ›› Issue (24): 5110-5116.doi: 10.3864/j.issn.0578-1752.2012.24.017

• 兽医 • 上一篇    

信号分子AI-2对禽致病性大肠杆菌的调控作用

 白灏, 韩先干, 刘蕾, 单雪芹, 宋军, 刘瑞, 董洪亮, 刘海文, 丁铲, 于圣青   

  1. 中国农业科学院上海兽医研究所,上海 200241
  • 收稿日期:2012-10-26 出版日期:2012-12-15 发布日期:2012-12-14
  • 通讯作者: 通信作者于圣青,Tel:021-34293461;E-mail:yus@shvri.ac.cn;韩先干,Tel:021-34293412;E-mail:hanxgan@163.com
  • 作者简介:白 灏,Tel:021-34293153;E-mail:baihao07@163.com
  • 基金资助:

    国家自然科学基金项目(31001078,31072161,30871851)

The Regulation of Autoinducer-2 in Avian Pathogenic Escherichia coli

 BAI  Hao, HAN  Xian-Gan, LIU  Lei, DAN  Xue-Qin, SONG  Jun, LIU  Rui, DONG  Hong-Liang, LIU  Hai-Wen, DING  Chan, YU  Sheng-Qing   

  1. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241
  • Received:2012-10-26 Online:2012-12-15 Published:2012-12-14

摘要: 【目的】研究信号分子AI-2对禽致病性大肠杆菌(APEC)的调控作用。【方法】采用改良结晶紫半定量法和荧光染色法检测AI-2对APEC生物被膜形成能力的影响。Real-time PCR检测AI-2对APEC毒力基因转录水平的影响。活菌计数法观察AI-2对APEC黏附和入侵鸡胚成纤维细胞DF-1的影响。【结果】AI-2在浓度为0.185 mmol•L-1时,生物被膜形成能力显著增强,而浓度为0.037mmol•L-1和0.285mmol•L-1时,生物被膜形成能力无显著变化。Real-time PCR结果显示加入AI-2后,APEC毒力基因pfs,vat,luxS,tsh,fuyA,iucD转录水平显著下调,ompA和iss则上调。加入AI-2后,APEC对DF-1细胞的黏附和入侵能力分别下降到原来的57.35%和36.64%。【结论】AI-2对禽致病性大肠杆菌生物被膜形成具有浓度依赖性,在适宜浓度下能显著增强。AI-2能减弱禽致病性大肠杆菌毒力基因的转录水平和对DF-1的黏附和入侵能力。表明AI-2参与调控APEC致病性。

关键词: 禽致病性大肠杆菌 , AI-2 , 生物被膜 , 毒力基因 , 黏附 , 入侵

Abstract: 【Objective】 The aim of the study was to investigate the modulation of AI-2 on the biofilm forming ability and virulence in Avian Pathogenic Escherichia coli (APEC). 【Method】 The improved crystal violet seme-quantitative method and fluorescence staining method were used to study the effects of AI-2 on the biofilm forming ability in APEC. The effects of AI-2 on the mRNA levels of the virulence genes were analyzed using real-time PCR. Viable bacteria counting method was used to evaluate the effects of AI-2 on the capability of APEC to adhere and invade DF-1cell. 【Result】The results showed that the biofilm forming ability decreased at the concentration of 0.185 mmol•L-1 AI-2,while the biofilm forming ability had no significant change at the concentration of 0.037mmol•L-1 and 0.278 mmol•L-1 AI-2. Real-time PCR showed that Al-2 decreased the transcription of pfs, vat, lux, tsh, fuyA, iucD genes, while increased the transcription of ompA and iss genes. The adherence and invasion was decreased to 57.35% and 36.64% by supplementation with AI-2 in APEC. 【Conclusion】The biofilm forming ability increased at an optimal concentration of AI-2. The transcription of the virulence genes, the adherence and invasion to DF-1 cells of the bacteria were decreased by supplementation with AI-2 in the medium to culture the APEC. These findings will be of benefit to future studies of the role of AI-2 in APEC.

Key words: Avian Pathogenic Escherichia coli , AI-2 , biofilm , virulence genes , adherence , invasion