Evolution of atypical enteropathogenic E. coli by repeated acquisition of LEE pathogenicity island variants
Evolution of atypical enteropathogenic E. coli by repeated acquisition of LEE pathogenicity island variants
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DOI：
10.1038/nmicrobiol.2015.10
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发表时间：
2016-02-01
影响因子：
28.3
通讯作者：
Holt, Kathryn E.
中科院分区：
文献类型：
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作者：
Ingle, Danielle J.;Tauschek, Marija;Holt, Kathryn E.
非典型肠致病性大肠杆菌（aEPEC）是大肠杆菌的总称。大肠杆菌具有肠上皮细胞消失位点（LEE）编码的III型分泌系统，但缺乏肠出血性大肠杆菌特有的毒力因子（stx、bfpA）。大肠杆菌和典型的EPEC。由aEPEC引起的疾病负担最近在工业化国家和发展中国家有所增加，但对这种新兴病原体的种群结构和毒力特征知之甚少。在这里，我们生成了全球肠道多中心研究期间从亚洲和非洲的7个研究地点收集的185个aEPEC分离株的全基因组序列，并将其与公开可用的E.大肠杆菌基因组。系统基因组学分析揭示了10个不同的广泛分布的aEPEC克隆。LEE致病岛的遗传变异分析确定了30种不同的LEE亚型，分为三大谱系。每个LEE谱系表现出一个首选的染色体插入位点和不同的互补的非LEE编码的效应基因，表明这些谱系的进化模式不同。这项研究提供了第一个详细的基因组框架aEPEC的背景下，EPEC致病型，并将促进进一步研究EPEC的流行病学和致病性，使检测和跟踪特定的克隆和LEE变异。
Atypical enteropathogenic Escherichia coli (aEPEC) is an umbrella term given to E. coli that possess a type III secretion system encoded in the locus of enterocyte effacement (LEE), but lack the virulence factors (stx, bfpA) that characterize enterohaemorrhagic E. coli and typical EPEC, respectively. The burden of disease caused by aEPEC has recently increased in industrialized and developing nations, yet the population structure and virulence profile of this emerging pathogen are poorly understood. Here, we generated whole-genome sequences of 185 aEPEC isolates collected during the Global Enteric Multicenter Study from seven study sites in Asia and Africa, and compared them with publicly available E. coli genomes. Phylogenomic analysis revealed ten distinct widely distributed aEPEC clones. Analysis of genetic variation in the LEE pathogenicity island identified 30 distinct LEE subtypes divided into three major lineages. Each LEE lineage demonstrated a preferred chromosomal insertion site and different complements of non-LEE encoded effector genes, indicating distinct patterns of evolution of these lineages. This study provides the first detailed genomic framework for aEPEC in the context of the EPEC pathotype and will facilitate further studies into the epidemiology and pathogenicity of EPEC by enabling the detection and tracking of specific clones and LEE variants.