Molecular analysis as an aid to assess the public health risk of non-O157 Shiga toxin-producing Escherichia coli strains
Molecular analysis as an aid to assess the public health risk of non-O157 Shiga toxin-producing Escherichia coli strains
复制标题
DOI：
10.1128/aem.02566-07
复制
发表时间：
2008-04-01
影响因子：
4.4
通讯作者：
Karmali, Mohamed A.
中科院分区：
文献类型：
--
作者：
Coombes, Brian K.;Wickham, Mark E.;Karmali, Mohamed A.
产志贺毒素的大肠杆菌(STEC)菌株是牛的共生菌，具有很高的环境和人畜传播潜力。虽然O157：H7是最常见的STEC血清型，但人们越来越关注全球分布的200多种高毒力非O157 STEC血清型，其中一些与暴发和/或严重的人类疾病有关，如溶血性尿毒症综合征(HUS)和出血性结肠炎。目前，非O157 STEC毒力潜势的潜在遗传基础尚不清楚，尽管水平基因转移和获得新的致病岛是可能的来源。我们使用血清病理分类作为框架，以确定区分对人类构成严重风险的非O157 STEC菌株和与严重和流行疾病无关的STEC菌株的遗传元件。我们报告了在非O157 STEC菌株中发现了编码非Lee效应(NLE)基因的三个基因组岛和14个单独的NLE基因，这些基因与人类暴发和HUS潜力独立相关。讨论了对可传播的人畜共患病传播和公共卫生的影响。这些结果和方法提供了一种分子风险评估战略，以快速识别和应对来自环境和动物来源的可能对人类构成严重公共卫生风险的非O157 STEC菌株。
Shiga toxin-producing Escherichia coli (STEC) strains are commensal bacteria in cattle with high potential for environmental and zoonotic transmission to humans. Although O157:H7 is the most common STEC serotype, there is growing concern over the emergence of more than 200 highly virulent non-O157 STEC serotypes that are globally distributed, several of which are associated with outbreaks and/or severe human illness such as hemolytic-uremic syndrome (HUS) and hemorrhagic colitis. At present, the underlying genetic basis of virulence potential in non-O157 STEC is unknown, although horizontal gene transfer and the acquisition of new pathogenicity islands are an expected origin. We used seropathotype classification as a framework to identify genetic elements that distinguish non-O157 STEC strains posing a serious risk to humans from STEC strains that are not associated with severe and epidemic disease. We report the identification of three genomic islands encoding non-LEE effector (nle) genes and 14 individual nle genes in non-O157 STEC strains that correlate independently with outbreak and HUS potential in humans. The implications for transmissible zoonotic spread and public health are discussed. These results and methods offer a molecular risk assessment strategy to rapidly recognize and respond to non-O157 STEC strains from environmental and animal sources that might pose serious public health risks to humans.