Jensen C, Ethelberg S, Olesen B, Schiellerup P, Olsen K E P, Scheutz F, Nielsen E M, Neimann J, Høgh B, Gerner-Smidt P, Mølbak K, Krogfelt K A
Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark.
Clin Microbiol Infect. 2007 Sep;13(9):863-72. doi: 10.1111/j.1469-0691.2007.01773.x.
This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin-producing E. coli (VTEC), isolated in a case-control study of Danish children aged <5 years. Among 424 children with diarrhoea and 866 healthy controls, EPEC and VTEC were more prevalent in cases (2.4% and 2.6%, respectively) than in controls (0.7% and 0.7%, respectively). There was a high frequency of A/EEC isolates (n = 121), but these were equally prevalent in cases (11.3%) and controls (12.5%), and comprised a heterogeneous distribution of O:H serotypes. The intimin (eae) subtypes in A/EEC isolates showed an even distribution; the eae-gamma subtype predominated in classical EPEC cases. The virulence genes encoding the bundle-forming pilus (bfpA) and enteroaggregative heat-stable enterotoxin (astA) were rare among all isolates, and seemed to be of limited pathogenic importance in this population. Virulence characterisation of A/EEC isolates did not reveal any significant differences between cases and controls. Colonisation of children with A/EEC was associated with contact with sheep or goats (OR 2.2). The role of A/EEC, not being VTEC or belonging to the classical EPEC serotypes, requires further clarification, but serotyping is useful in discriminating between EPEC and A/EEC strains.
本研究描述了在一项针对丹麦5岁以下儿童的病例对照研究中分离出的黏附性和侵蚀性大肠杆菌菌株的流行情况、临床表现及微生物学特征，即属于经典肠致病性大肠杆菌（EPEC）血清型的肠致病性大肠杆菌、非EPEC黏附性和侵蚀性大肠杆菌（A/EEC）以及产志贺毒素大肠杆菌（VTEC）。在424例腹泻儿童和866例健康对照中，EPEC和VTEC在病例组中的流行率更高（分别为2.4%和2.6%），而在对照组中分别为0.7%和0.7%。A/EEC菌株的频率较高（n = 121），但在病例组（11.3%）和对照组（12.5%）中的流行率相同，且O:H血清型分布不均一。A/EEC菌株中的紧密黏附素（eae）亚型分布均匀；eae-γ亚型在经典EPEC病例中占主导。在所有分离株中，编码束状菌毛（bfpA）和肠聚集性耐热肠毒素（astA）的毒力基因很少见，在该人群中似乎致病性有限。A/EEC分离株的毒力特征在病例组和对照组之间未显示出任何显著差异。儿童感染A/EEC与接触绵羊或山羊有关（比值比2.2）。不属于VTEC或经典EPEC血清型的A/EEC的作用需要进一步阐明，但血清分型有助于区分EPEC和A/EEC菌株。
