A role for ColV plasmids in the evolution of pathogenic Escherichia coli ST58

Escherichia coli ST58 has recently emerged as a globally disseminated uropathogen that often progresses to sepsis. Unlike most pandemic extra-intestinal pathogenic E. coli (ExPEC), which belong to pathogenic phylogroup B2, ST58 belongs to the environmental/commensal phylogroup B1. Here, we present a pan-genomic analysis of a global collection of 752 ST58 isolates from diverse sources. We identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage includes three-quarters of all ExPEC sequences in our study and has a broad host range, although poultry and porcine sources predominate. By contrast, strains isolated from cattle often lack ColV plasmids. Our data indicate that ColV plasmid acquisition contributed to the divergence of the major ST58 sub-lineage, and different sub-lineages inhabit poultry, swine and cattle. Escherichia coli ST58 has recently emerged as a globally disseminated extra-intestinal pathogen. Here, Reid et al. present a pan-genomic analysis of a global collection of ST58 isolates from animal and human sources, showing that ColV plasmid acquisition likely contributed to the divergence of a major sub-lineage that has a broad host range but is more commonly found in poultry and swine.

Automated summary

This study presents a pan-genomic analysis of Escherichia coli ST58 isolates from animal and human sources. The analysis reveals a major sub-lineage of ST58 that is characterized by the presence of ColV plasmids carrying virulence genes, and a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage has a broad host range, with poultry and swine being the predominant sources.