title: Characteristics of clinical Shiga toxin-producing Escherichia coli isolated from British Columbia.
abstract: Shiga toxin-producing Escherichia coli (STEC) are significant public health threats. Although STEC O157 are recognized foodborne pathogens, non-O157 STEC are also important causes of human disease. We characterized 10 O157:H7 and 15 non-O157 clinical STEC derived from British Columbia (BC). Eae, hlyA, and stx were more frequently observed in STEC O157, and 80 and 100% of isolates possessed stx₁ and stx₂, respectively. In contrast, stx₁ and stx₂ occurred in 80 and 40% of non-O157 STEC, respectively. Comparative genomic fingerprinting (CGF) revealed three distinct clusters (C). STEC O157 was identified as lineage I (LI; LSPA-6 111111) and clustered as a single group (C1). The cdi gene previously observed only in LII was seen in two LI O157 isolates. CGF C2 strains consisted of diverse non-O157 STEC while C3 included only O103:H25, O118, and O165 serogroup isolates. With the exception of O121 and O165 isolates which were similar in virulence gene complement to STEC O157, C1 O157 STEC produced more Stx2 than non-O157 STEC. Antimicrobial resistance (AMR) screening revealed resistance or reduced sensitivity in all strains, with higher levels occurring in non-O157 STEC. One STEC O157 isolate possessed a mobile bla(CMY-2) gene transferrable across genre via conjugation.
authors.affiliation: Food, Nutrition and Health Program, Faculty of Land and Food Systems, University of British Columbia, 218-2205 East Mall, Vancouver, BC, Canada V6T 1Z4.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Allen
authors.forename: Chad R
authors.initials: CR
authors.lastname: Laing
authors.forename: Ana
authors.initials: A
authors.lastname: Cancarevic
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lili R
authors.initials: LR
authors.lastname: Mesak
authors.forename: Hai
authors.initials: H
authors.lastname: Xu
authors.forename: Ana
authors.initials: A
authors.lastname: Paccagnella
authors.forename: Victor P J
authors.initials: VP
authors.lastname: Gannon
authors.forename: Linda
authors.initials: L
authors.lastname: Hoang
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D001955:British Columbia; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D029968:Escherichia coli Proteins / Q000235:genetics; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics; D006801:Humans; D012703:Serotyping; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli