Chicken‐source Escherichia coli within Phylogroup F Shares Virulence Genotypes and is Closely Related to Extraintestinal pathogenic E. coli (ExPEC) Causing Human Infections

ExPEC is an important pathogen that causes diverse infection in the humans extraintestinal sites. Although avian-source phylogroup F E. coli isolates hold a high level of virulence traits, few studies have systematically assessed the pathogenicity and zoonotic potential of E. coli isolates within phylogroup F. A total of 1332 E. coli strains were recovered from chicken colibacillosis in China from 2012 to 2017. About 21.7% of chicken-source E. coli isolates were presented in phylogroup F. We characterized phylogroup F E. coli isolates both genotypically and phenotypically. There was a widespread prevalence of ExPEC virulence-related genes among chicken-source E. coli isolates within phylogroup F. ColV/BM plasmid-related genes (i.e. hlyF, mig-14p, ompTp, iutA, and tsh) occurred in the nearly 65% phylogroup F E. coli isolates. Population structure of chicken-source E. coli isolates within phylogroup F were revealed and contained several dominant STs (such as ST59, ST354, ST362, ST405, ST457, and ST648). Most chicken-source phylogroup F E. coli held the property to produce biofilm, and exhibited strongly swimming and swarming motilities. Our result showed that the complement resistance of phylogroup F E. coli isolates was closely associated with its virulence genotype. Our research further demonstrated the zoonotic potential of chicken-source phylogroup F E. coli isolates. The phylogroup F E. coli isolates were able to cause multiple diseases in animal models of avian colibacillosis and human infections (sepsis, meningitis, and UTI). The chicken-source phylogroup F isolates, especially dominant ST-types, might be recognized as a high-risk foodborne pathogen. This was the first study to identify that chicken-source E. coli isolates within phylogroup F were associated with human ExPEC pathotypes and exhibited zoonotic potential.