Complete Genome Sequence and Comparative Genome Analysis of Enteropathogenic Escherichia coli O127:H6 Strain E2348/69
Complete Genome Sequence and Comparative Genome Analysis of Enteropathogenic Escherichia coli O127:H6 Strain E2348/69
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DOI：
10.1128/jb.01238-08
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发表时间：
2009-01-01
影响因子：
3.2
通讯作者：
Frankel, Gad
中科院分区：
文献类型：
--
作者：
Iguchi, Atsushi;Thomson, Nicholas R.;Frankel, Gad
肠致病性大肠杆菌（EPEC）是大肠杆菌的第一致病变种。大肠杆菌与人类疾病有关;然而，到目前为止还没有EPEC菌株被完全测序。菌株E2348/69（血清型为O 127：H6，属于E.大肠杆菌EPEC B2群）已在全世界用作研究EPEC生物学、遗传学和毒力的原型菌株。对E2348/69的研究发现了肠上皮细胞消失编码的III型分泌系统（T3 SS）及其同源效应子的位点，其在肠上皮细胞上的附着和消失病变形成中起重要作用。在本研究中，我们测定了E2348/69的全基因组序列，并与其他重要的E.大肠杆菌菌株。我们鉴定了424个E2348/69特异性基因，其中大部分基因携带在移动的遗传元件上，以及许多在E2348/69中特异性保守的遗传性状，包括ETT 2相关的T3 SS的缺失，该基因存在于E.大肠杆菌菌株属于所有其他大肠杆菌群。基因组分析揭示了与E2348/69毒力相关的整个基因库。有趣的是，E2348/69只含有21个完整的T3 SS效应基因，所有这些基因都携带在原噬菌体和整合元件上，而肠出血性大肠杆菌中有50多个效应基因。coli O157。E2348/69是目前研究最多的致病性大肠杆菌。大肠杆菌菌株，这项研究提供了大量的现有实验数据的基因组背景。E2348/69 T3 SS出乎意料的简单性首次提供了在基因组背景下全面剖析附着和消除病原体的整个毒力策略的机会。
Enteropathogenic Escherichia coli (EPEC) was the first pathovar of E. coli to be implicated in human disease; however, no EPEC strain has been fully sequenced until now. Strain E2348/69 (serotype O127:H6 belonging to E. coli phylogroup B2) has been used worldwide as a prototype strain to study EPEC biology, genetics, and virulence. Studies of E2348/69 led to the discovery of the locus of enterocyte effacement-encoded type III secretion system (T3SS) and its cognate effectors, which play a vital role in attaching and effacing lesion formation on gut epithelial cells. In this study, we determined the complete genomic sequence of E2348/69 and performed genomic comparisons with other important E. coli strains. We identified 424 E2348/69-specific genes, most of which are carried on mobile genetic elements, and a number of genetic traits specifically conserved in phylogroup B2 strains irrespective of their pathotypes, including the absence of the ETT2-related T3SS, which is present in E. coli strains belonging to all other phylogroups. The genome analysis revealed the entire gene repertoire related to E2348/69 virulence. Interestingly, E2348/69 contains only 21 intact T3SS effector genes, all of which are carried on prophages and integrative elements, compared to over 50 effector genes in enterohemorrhagic E. coli O157. As E2348/69 is the most-studied pathogenic E. coli strain, this study provides a genomic context for the vast amount of existing experimental data. The unexpected simplicity of the E2348/69 T3SS provides the first opportunity to fully dissect the entire virulence strategy of attaching and effacing pathogens in the genomic context.