Chicken-sourceEscherichia coliwithin phylogroup F shares virulence genotypes and is closely related to extraintestinal pathogenicE. colicausing human infections

ExPEC is an important pathogen that causes diverse infection in the human extraintestinal sites. Although avian-source phylogroup FEscherichia coliisolates hold a high level of virulence traits, few studies have systematically assessed the pathogenicity and zoonotic potential ofE. coliisolates within phylogroup F. A total of 1,332E. colistrains were recovered from chicken colibacillosis in China from 2012 to 2017. About 21.7% of chicken-sourceE. coliisolates were presented in phylogroup F. We characterized phylogroup FE. coliisolates both genotypically and phenotypically. There was a widespread prevalence of ExPEC virulence-related genes among chicken-sourceE. coliisolates within phylogroup F. ColV/BM plasmid-related genes (i.e.hlyF,mig-14p,ompTp,iutAandtsh) occurred in the nearly 65% of phylogroup FE. coliisolates. Population structure of chicken-sourceE. coliisolates within phylogroup F was revealed and contained several dominant STs (such as ST59, ST354, ST362, ST405, ST457 and ST648). Most chicken-source phylogroup FE. coliheld the property to produce biofilm and exhibited strongly swimming and swarming motilities. Our result showed that the complement resistance of phylogroup FE. coliisolates was closely associated with its virulence genotype. Our research further demonstrated the zoonotic potential of chicken-source phylogroup FE. coliisolates. The phylogroup FE. coliisolates 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 food-borne pathogen. This was the first study to identify that chicken-sourceE. coliisolates within phylogroup F were associated with human ExPEC pathotypes and exhibited zoonotic potential.

Automated summary

Chicken-source E. coli isolates within phylogroup F in China showed high prevalence of virulence-related genes, stable population structure, and strong biofilm formation, swimming, and swarming abilities. The research revealed the potential zoonotic transmission and association with human ExPEC pathotypes, indicating a potential high-risk food-borne pathogen.