title: Virulence, Antimicrobial Resistance Properties and Phylogenetic Background of Non-H7 EnteropathogenicEscherichia coliO157.
abstract: Escherichia coli(E.coli) O157 that do not produce Shiga toxin and do not possess flagellar antigen H7 are of diverse H serotypes. In this study, the antibiotic resistance properties, genotype of a set of virulence associated genes and the phylogenetic background ofE. coliO157:non-H7 groups were compared. Whole genome sequencing was performed on fourteen O157:non-H7 isolates collected in the STEC-ID-net study. The genomes were compared withE. coliO157 genomes and a typical EnteropathogenicE. coli(tEPEC) genome downloaded from NCBI. Twenty-six (86%) of the analyzed genomes had the intimin encoding geneeaebut of different types mostly correlating with their H types, e.g., H16, H26, H39, and H45 carried intimin type ε, β, κ, and α, respectively. They belonged to severalE. coliphylogenetic groups, i.e., to phylogenetic group A, B1, B2, and D. Seven (50%) of our collected O157:non-H7 isolates were resistant to two or more antibiotics. Several mobile genetic elements, such as plasmids, insertion elements, and pathogenicity islands, carrying a set of virulence and resistance genes were found in theE. coliO157:non-H7 isolates. Core genome phylogenetic analysis showed that O157:non-H7 isolates probably evolved from different phylogenetic lineages and were distantly related to theE. coliO157:H7 lineage. We hypothesize that independent acquisition of mobile genetic elements by isolates of different lineages have contributed to the different molecular features of the O157:non-H7 strains. Although distantly related to the STEC O157,E. coliO157:non-H7 isolates from multiple genetic background could be considered as pathogen of concern for their diverse virulence and antibiotic resistance properties.
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen, University of Groningen Groningen, Netherlands.
authors.forename: Mithila
authors.initials: M
authors.lastname: Ferdous
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; Department of Medical Microbiology, Certe Laboratory for Infectious DiseasesGroningen, Netherlands.
authors.forename: Anna M D
authors.initials: AM
authors.lastname: Kooistra-Smid
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhou
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen, University of Groningen Groningen, Netherlands.
authors.forename: John W A
authors.initials: JW
authors.lastname: Rossen
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen, University of Groningen Groningen, Netherlands.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Friedrich
keywords: antimicrobial resistance; enteropathogenic Escherichia coli (EPEC); evolution; mobile genetic elements; phylogenetic relationship; virulence; whole genome sequencing