Identification and characterisation of novel virulence genes in attaching and effacing strains of Escherichia coli

大肠杆菌附着和消除菌株中新毒力基因的鉴定和表征

• 批准号: nhmrc : 216709
• 负责人: Prof Elizabeth Hartland
• 金额: $ 18.76万
• 依托单位: Murdoch Childrens Research Institute
• 依托单位国家: 澳大利亚
• 项目类别: NHMRC Project Grants
• 财政年份: 2002
• 资助国家: 澳大利亚
• 起止时间: 2002-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/identification-characterisation-novel-escherichia-coli/99958
• 关键词: Identification; characterisation; novel; virulence; genes

Some varieties of Escherichia (E.) coli are harmless bacteria that live in the healthy intestinal tract, whereas others can cause diarrhoea. Those varieties of E. coli which cause diarrhoea include so-called enteropathogenic E. coli (EPEC), which is a leading cause of life- diarrhoea in infants and young children in less developed countries, and enterohaemorrhagic E. coli (EHEC) the cause of hamburger disease. These bacteria are able to cause disease because they possess specific genetic information that is absent from harmless varieties of E. coli. Although many of these disease-associated genes have been identified, the specific role of many of them is not known. In addition, it seems likely that many more genes of this type remain to be discovered. The fact that EPEC is host specific means that the mechanisms by which these bacteria cause disease can only be investigated in humans. This is extremely limiting for the number and type of investigations that can be performed. However, there are rabbit-specific strains of EPEC which cause a disease in rabbits that is indistinguishable from that caused by EPEC in children. The aims of this study are to use the rabbit model of diarrhoea to learn more about the contribution of certain specific factors of EPEC to disease causation and to discover new factors of this type. This will be achieved by three complementary strategies: (1) investigating rabbit E. coli for virulence genes and determining if they are present in human strains; (2) examining the effect of inactivating these genes on the ability of E. coli to cause diarrhoea in rabbits; and (3) infecting rabbits with pools of mutant E. coli strains to identify factors that the bacteria require to survive in rabbits. The results of these studies will improve understanding of the mechanisms by which E. coli cause disease and may provide opportunities for the development of novel tools to diagnose, treat and prevent E. coli-associated diarrhoea.

Escherichia（E.）大肠杆菌是生活在健康肠道内的无害细菌，而其他细菌则会导致腹泻。E.引起腹泻的大肠杆菌包括所谓的肠病原性大肠杆菌。大肠杆菌（EPEC），这是一个主要的原因，生活在欠发达国家的婴儿和幼儿腹泻，肠出血性大肠杆菌。大肠杆菌（EHEC）是汉堡包病的病因。这些细菌能够引起疾病，因为它们拥有特定的遗传信息，而这些信息是无害的E。杆菌虽然这些疾病相关基因中的许多已经被确定，但其中许多基因的具体作用尚不清楚。此外，似乎还有更多的这种类型的基因有待发现。EPEC是宿主特异性的事实意味着这些细菌引起疾病的机制只能在人类中进行研究。这极大地限制了可以进行的调查的数量和类型。然而，存在兔特异性的EPEC菌株，其在兔中引起的疾病与在儿童中由EPEC引起的疾病难以区分。本研究的目的是利用兔腹泻模型，了解更多关于EPEC的某些特定因素对疾病病因的贡献，并发现这种类型的新因素。这将通过三个互补的策略来实现：（1）调查兔E。大肠杆菌中的毒力基因，并确定它们是否存在于人类菌株中;大肠杆菌致家兔腹泻;（3）用突变大肠杆菌混合物感染家兔。大肠杆菌菌株，以确定细菌在兔子体内生存所需的因素。这些研究的结果将提高对E.大肠杆菌引起的疾病，并可能提供新的工具，诊断，治疗和预防大肠杆菌的发展机会。大肠杆菌相关腹泻。