Escherichia coli includes clonal groups of both commensal and pathogenic strains, with some of the latter causing serious infectious diseases. O antigen variation is current standard in defining strains for taxonomy and epidemiology, providing the basis for many serotyping schemes for Gram-negative bacteria. This review covers the diversity in E. coli O antigen structures and gene clusters, and the genetic basis for the structural diversity. Of the 187 formally defined O antigens, six (O31, O47, O67, O72, O94 and O122) have since been removed and three (O34, O89 and O144) strains do not produce any O antigen. Therefore, structures are presented for 176 of the 181 E. coli O antigens, some of which include subgroups. Most (93%) of these O antigens are synthesized via the Wzx/Wzy pathway, 11 via the ABC transporter pathway, with O20, O57 and O60 still uncharacterized due to failure to find their O antigen gene clusters. Biosynthetic pathways are given for 38 of the 49 sugars found in E. coli O antigens, and several pairs or groups of the E. coli antigens that have related structures show close relationships of the O antigen gene clusters within clades, thereby highlighting the genetic basis of the evolution of diversity.

中文翻译：

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大肠杆菌O抗原的结构和遗传

大肠杆菌包括共生和致病菌株的克隆群，其中一些会引起严重的传染病。O抗原变异是确定分类学和流行病学菌株的当前标准，为革兰氏阴性细菌的许多血清分型方案提供了基础。这篇综述涵盖了大肠杆菌O抗原结构和基因簇的多样性，以及结构多样性的遗传基础。此后，在187种形式明确的O抗原中，有6种（O31，O47，O67，O72，O94和O122）已被去除，其中3种（O34，O89和O144）菌株不产生任何O抗原。因此，提出了181株大肠杆菌中176株的结构O抗原，其中一些包括亚组。这些O抗原中的大多数（93％）通过Wzx / Wzy途径合成，通过ABC转运蛋白途径合成11，由于未能找到O抗原基因簇，O20，O57和O60仍未表征。给出了大肠杆菌O抗原中发现的49种糖中的38种的生物合成途径，具有相关结构的几对或几组大肠杆菌抗原显示进化枝中O抗原基因簇的紧密关系，从而突出了遗传基础多样性的演变。