title: Characterization of urinary tract infection-associated Shiga toxin-producing Escherichia coli.
abstract: Enterohemorrhagic Escherichia coli (EHEC), a subgroup of Shiga toxin (Stx)-producing E. coli (STEC), is a leading cause of diarrhea and hemolytic-uremic syndrome (HUS) in humans. However, urinary tract infections (UTIs) caused by this microorganism but not associated with diarrhea have occasionally been reported. We geno- and phenotypically characterized three EHEC isolates obtained from the urine of hospitalized patients suffering from UTIs. These isolates carried typical EHEC virulence markers and belonged to HUS-associated E. coli (HUSEC) clones, but they lacked virulence markers typical of uropathogenic E. coli. One isolate exhibited a localized adherence (LA)-like pattern on T24 urinary bladder epithelial cells. Since the glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer) are well-known receptors for Stx but also for P fimbriae, a major virulence factor of extraintestinal pathogenic E. coli (ExPEC), the expression of Gb3Cer and Gb4Cer by T24 cells and in murine urinary bladder tissue was examined by thin-layer chromatography and mass spectrometry. We provide data indicating that Stxs released by the EHEC isolates bind to Gb3Cer and Gb4Cer isolated from T24 cells, which were susceptible to Stx. All three EHEC isolates expressed stx genes upon growth in urine. Two strains were able to cause UTI in a murine infection model and could not be outcompeted in urine in vitro by typical uropathogenic E. coli isolates. Our results indicate that despite the lack of ExPEC virulence markers, EHEC variants may exhibit in certain suitable hosts, e.g., in hospital patients, a uropathogenic potential. The contribution of EHEC virulence factors to uropathogenesis remains to be further investigated.
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Francisco
authors.initials: F
authors.lastname: Toval
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
authors.forename: Roswitha
authors.initials: R
authors.lastname: Schiller
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Meisen
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Putze
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Ivan U
authors.initials: IU
authors.lastname: Kouzel
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Wenlan
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Karch
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Bielaszewska
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Mormann
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Müthing
authors.affiliation: Institute of Hygiene, University of Münster, Münster, Germany Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany dobrindt@uni-muenster.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dobrindt
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002460:Cell Line; D003556:Cystitis / Q000382:microbiology*; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D051379:Mice; D014552:Urinary Tract Infections / Q000382:microbiology*; D055815:Young Adult