Chattaway Marie Anne, Dallman Tim, Okeke Iruka N, Wain John
Laboratory of Gastrointestinal Pathogens, Health Protection Agency, London, England.
J Infect Dev Ctries. 2011 Jul 4;5(6):425-36. doi: 10.3855/jidc.2166.
Enterohaemorrhagic E. coli (EHEC) particularly O157:H7 (Sequence type 11 complex), is the best documented and most well-known of E. coli that cause diarrhoea. The importance of EHEC lies in the severity of disease. Outbreaks can infect thousands of people causing bloody diarrhoea and haemolytic uremic syndrome (HUS) that in turn can result in protracted illness or even death. The ability of EHEC to colonise the human gut is normally associated with the presence of genes from another group of diarrhoeagenic E. coli, the enteropathogenic E. coli (EPEC), via the locus of enterocyte effacement. However, the massive outbreak in Germany was caused by an EHEC which had acquired virulence genes from yet another group of diarrhoeagenic E. coli, the enteroaggregative E. coli (EAEC). In reality EAEC is probably the most common bacterial cause of diarrhoea but is not identified in most diagnostic laboratories. This outbreak emphasises the importance of being able to detect all diarrhoeagenic E. coli and not to focus on E. coli O157:H7 alone. Routine surveillance systems for EAEC, a once ignored global pathogen, would go a long way to reaching this goal. This review describes methods for identifying non-O157 EHEC and describes the key genetic features of EHEC and EAEC. Our aim is to provide information for laboratories and policy makers which enables them to make informed decisions about the best methods available for detecting newly emergent strains of diarrhoeagenic E. coli.
肠出血性大肠杆菌（EHEC），尤其是O157:H7（序列型11复合体），是引发腹泻的大肠杆菌中记录最完备、最为人所知的菌株。EHEC的重要性在于其疾病的严重性。疫情爆发可感染数千人，导致血性腹泻和溶血尿毒综合征（HUS），进而可能导致长期患病甚至死亡。EHEC在人类肠道中定殖的能力通常与另一组致泻性大肠杆菌——肠致病性大肠杆菌（EPEC）的基因通过肠细胞损伤位点的存在有关。然而，德国的大规模疫情是由一种从另一组致泻性大肠杆菌——肠聚集性大肠杆菌（EAEC）获得毒力基因的EHEC引起的。实际上，EAEC可能是腹泻最常见的细菌病因，但在大多数诊断实验室中并未得到识别。此次疫情凸显了能够检测所有致泻性大肠杆菌而非仅关注O157:H7大肠杆菌的重要性。针对EAEC（一种曾被忽视的全球病原体）的常规监测系统将大大有助于实现这一目标。本综述描述了鉴定非O157 EHEC的方法，并描述了EHEC和EAEC的关键遗传特征。我们的目的是为实验室和政策制定者提供信息，使他们能够就检测新出现的致泻性大肠杆菌菌株的最佳可用方法做出明智的决策。
