Increase in bacteraemia cases in the East Midlands region of the UK due to MDR Escherichia coli ST73: high levels of genomic and plasmid diversity in causative isolates
Increase in bacteraemia cases in the East Midlands region of the UK due to MDR Escherichia coli ST73: high levels of genomic and plasmid diversity in causative isolates
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DOI：
10.1093/jac/dkv365
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发表时间：
2016-02-01
影响因子：
5.2
通讯作者：
Mcnally, Alan
中科院分区：
文献类型：
--
作者：
Alhashash, Fahad;Wang, Xiaohui;Mcnally, Alan
本研究的目的是确定从人类菌血症和泌尿道感染中分离的大肠杆菌ST 73的种群结构。使用Illumina HiSeq平台对大肠杆菌ST 73分离株进行测序。高分辨率SNP分型用于创建系统发育树。还使用泛基因组方法进行比较基因组学。进行了计算机模拟和S1-PFGE质粒谱分析，并检查了分离株暴露于人血清后存活的能力。在临床上不相关的事件中循环的大肠杆菌ST 73分离株在全基因组水平上显示出高度的多样性，但在基因内容上表现出保守性，特别是在毒力相关基因携带方面。这些分离株还含有一个高度多样的质粒库，通过携带CTX-M基因而产生MDR。大肠杆菌ST 73临床分离株不是由于流行爆发菌株，如在大肠杆菌中。coli ST 131。相反，ST 73循环菌株是远亲，并携带一组不同的耐药质粒。这表明，耐药大肠杆菌出现背后的进化事件。大肠杆菌在不同谱系之间存在差异。
The objective of this study was to determine the population structure of Escherichia coli ST73 isolated from human bacteraemia and urinary tract infections.The genomes of 22 E. coli ST73 isolates were sequenced using the Illumina HiSeq platform. High-resolution SNP typing was used to create a phylogenetic tree. Comparative genomics were also performed using a pangenome approach. In silico and S1-PFGE plasmid profiling was conducted, and isolates were checked for their ability to survive exposure to human serum.E. coli ST73 isolates circulating in clinically unrelated episodes show a high degree of diversity at a whole-genome level, but exhibit conservation in gene content, particularly in virulence-associated gene carriage. The isolates also contain a highly diverse plasmid pool that confers MDR via carriage of CTX-M genes.Our data show that a rise in incidence of MDR E. coli ST73 clinical isolates is not due to a circulating outbreak strain as in E. coli ST131. Rather the ST73 circulating strains are distantly related and carry a diverse set of resistance plasmids. This suggests that the evolutionary events behind emergence of drug-resistant E. coli differ between lineages.