Genetic diversity and features analysis of type VI secretion systems loci in avian pathogenic Escherichia coli by wide genomic scanning
Genetic diversity and features analysis of type VI secretion systems loci in avian pathogenic Escherichia coli by wide genomic scanning
复制标题
通过广泛基因组扫描分析禽类致病性大肠杆菌 VI 型分泌系统位点的遗传多样性和特征。
DOI：
10.1016/j.meegid.2013.09.031
复制
发表时间：
2013-12-01
影响因子：
3.2
通讯作者：
Yao, Huochun
中科院分区：
文献类型：
--
作者：
Ma, Jiale;Sun, Min;Yao, Huochun
禽致病性大肠杆菌（APEC）是引起禽肠道外感染的常见病原菌，造成了严重的经济损失。近年来的研究表明，VI型分泌系统（T6 SS）参与了APEC的发病机制。在这里，我们提供了APEC基因组中三个可区分且保守的T6 SS基因座的第一个证据。此外，我们提出的患病率和比较基因组分析这三个T6 SS位点在472 APEC分离株。T6 SS 1、T6 SS 2和T6 SS 3位点在APEC分离株中的检出率分别为14.62%（69/472）、2.33%（11/472）和0.85%（4/472），表明85%以上的分离株含有T6 SS位点，由毒力系统发育群D和B2组成。综合分析表明，T6 SS 1基因具有广泛的流行性、丰富的序列多样性、多样的VgrG岛以及在多种大肠杆菌中良好的表达能力等特点。大肠杆菌致病型。而T6 SS 2基因座则是ECOR B2群，序列保守，仅在脑膜炎E.杆菌令人遗憾的是，T6 SS 3基因座编码在微不足道的APEC分离物，缺乏几个关键基因。对VgrG蛋白的深入分析表明，其COG 4253和gp 27结构域分别参与了效应岛的转运和宿主细胞的识别，表明VgrG蛋白在T6 SS功能形成中起重要作用。(C)2013作者由Elsevier B出版。V.保留所有权利。
Avian pathogenic Escherichia coli (APEC) strains frequently cause extra-intestinal infections and significant economic losses. Recent studies revealed that the type VI secretion system (T6SS) is involved in APEC pathogenesis. Here we provide the first evidence of three distinguishable and conserved T6SS loci in APEC genomes. In addition, we present the prevalence and comparative genomic analysis of these three T6SS loci in 472 APEC isolates. The prevalence of T6SS1, T6SS2 and T6SS3 loci were 14.62% (69/472), 2.33% (11/472) and 0.85% (4/472) positive in the APEC collections, respectively, and revealed that >85% of the strains contained T6SS loci which consisted of the virulent phylogenetic groups D and B2. Comprehensive analysis showed prominent characteristics of T6SS1 locus, including wildly prevalence, rich sequence diversity, versatile VgrG islands and excellent expression competence in various E. coli pathotypes. Whereas the T6SS2 locus infatuated with ECOR groups B2 and sequence conservation, of which are only expressed in meningitis E. coli. Regrettably, the T6SS3 locus was encoded in negligible APEC isolates and lacked several key genes. An in-depth analysis about VgrG proteins indicated that their COG4253 and gp27 domain were involved in the transport of putative effector islands and recognition of host cells respectively, which revealed that VgrG proteins played an important role in functions formation of T6SS. (C) 2013 The Authors. Published by Elsevier B. V. All rights reserved.