Anjum Muna F, Lucchini Sacha, Thompson Arthur, Hinton Jay C D, Woodward Martin J
Department of Bacterial Diseases, Veterinary Laboratories Agency-Weybridge, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom.
Infect Immun. 2003 Aug;71(8):4674-83. doi: 10.1128/IAI.71.8.4674-4683.2003.
The Escherichia coli O26 serogroup includes important food-borne pathogens associated with human and animal diarrheal disease. Current typing methods have revealed great genetic heterogeneity within the O26 group; the data are often inconsistent and focus only on verotoxin (VT)-positive O26 isolates. To improve current understanding of diversity within this serogroup, the genomic relatedness of VT-positive and -negative O26 strains was assessed by comparative genomic indexing. Our results clearly demonstrate that irrespective of virulence characteristics and pathotype designation, the O26 strains show greater genomic similarity to each other than to any other strain included in this study. Our data suggest that enteropathogenic and VT-expressing E. coli O26 strains represent the same clonal lineage and that VT-expressing E. coli O26 strains have gained additional virulence characteristics. Using this approach, we established the core genes which are central to the E. coli species and identified regions of variation from the E. coli K-12 chromosomal backbone.
大肠杆菌O26血清群包含与人和动物腹泻病相关的重要食源性病原体。目前的分型方法已揭示出O26组内存在巨大的遗传异质性；数据往往不一致，且仅关注产志贺毒素（VT）的O26分离株。为了增进目前对该血清群内多样性的了解，通过比较基因组索引评估了产VT和不产VT的O26菌株的基因组相关性。我们的结果清楚地表明，无论毒力特征和致病型如何，O26菌株彼此之间的基因组相似性都高于本研究中包含的任何其他菌株。我们的数据表明，肠致病性和产VT的大肠杆菌O26菌株代表相同的克隆谱系，且产VT的大肠杆菌O26菌株获得了额外的毒力特征。利用这种方法，我们确定了对大肠杆菌物种至关重要的核心基因，并鉴定了与大肠杆菌K-12染色体主干的变异区域。
