Canine feces as a reservoir of extraintestinal pathogenic Escherichia coli.
To test the canine reservoir hypothesis of extraintestinal pathogenic Escherichia coli (ExPEC), 63 environmental canine fecal deposits were evaluated for the presence of ExPEC by a combination of selective culturing, extended virulence genotyping, hemagglutination testing, O serotyping, and PCR-based phylotyping. Overall, 30% of canine fecal samples (56% of those that yielded viable E. coli) contained papG-positive E. coli, usually as the predominant E. coli strain and always possessing papG allele III (which encodes variant III of the P-fimbrial adhesin molecule PapG). Multiple other virulence-associated genes typical of human ExPEC were prevalent among the canine fecal isolates. According to serotyping, virulence genotyping, and random amplified polymorphic DNA analysis, over 50% of papG-positive fecal E. coli could be directly correlated with specific human clinical isolates from patients with cystitis, pyelonephritis, bacteremia, or meningitis, including archetypal human ExPEC strains 536, CP9, and RS218. Five canine fecal isolates and (clonally related) archetypal human pyelonephritis isolate 536 were found to share a novel allele of papA (which encodes the P-fimbrial structural subunit PapA). These data confirm that ExPEC representing known virulent clones are highly prevalent in canine feces, which consequently may provide a reservoir of ExPEC for acquisition by humans.
Johnson
J R
JR
VA Medical Center and Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55417, USA. johns007@tc.umn.edu
Stell
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AL
Delavari
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D018830:Adhesins, Escherichia coli / Q000302:isolation & purification; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D004197:Disease Reservoirs / Q000662:veterinary*; D004285:Dogs; D004926:Escherichia coli / Q000145:classification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000209:etiology* / Q000662:veterinary; D029968:Escherichia coli Proteins; D005243:Feces / Q000382:microbiology*; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial; D014644:Genetic Variation; D008969:Molecular Sequence Data; D019081:O Antigens; D010641:Phenotype; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique; D012703:Serotyping; D014552:Urinary Tract Infections / Q000209:etiology* / Q000662:veterinary
D018830:Adhesins, Escherichia coli; C078802:AtpA protein, E coli; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D019081:O Antigens; C092426:PapG protein, E coli; D036781:Fimbriae Proteins