Phylogenetic group D extraintestinal pathogenic Escherichia coli (ExPEC), including O15:K52:H1 and clonal group A, have spread globally and become fluoroquinolone-resistant. Here we investigated the role of canine feces as a reservoir of these (and other) human-associated ExPEC and their potential as canine pathogens. We characterized and compared fluoroquinolone-resistant E. coli isolates originally identified as phylogenetic group D from either the feces of hospitalized dogs (n = 67; 14 dogs) or extraintestinal infections (n = 53; 33 dogs). Isolates underwent phylogenetic grouping, random amplified polymorphic DNA (RAPD) analysis, virulence genotyping, resistance genotyping, human-associated ExPEC O-typing, and multi-locus sequence typing. Five of seven human-associated sequence types (STs) exhibited ExPEC-associated O-types, and appeared in separate RAPD clusters. The largest subgroup (16 fecal, 26 clinical isolates) were ST354 (phylogroup F) isolates. ST420 (phylogroup B2); O1-ST38, O15:K52:H1-ST393, and O15:K1-ST130 (phylogroup D); and O7-ST457, and O1-ST648 (phylogroup F) were also identified. Three ST-specific RAPD sub-clusters (ST354, ST393, and ST457) contained closely related isolates from both fecal or clinical sources. Genes encoding CTX-M and AmpC β-lactamases were identified in isolates from five STs. Major human-associated fluoroquinolone-resistant ± extended-spectrum cephalosporin-resistant ExPEC of public health importance may be carried in dog feces and cause extraintestinal infections in some dogs.
Bibliographical noteFunding Information:
The assistance with sample collection from Ms Rhonda Foreman and Dr. Kenneth Cockwill from University Veterinary Teaching Hospital, Sydney is gratefully acknowledged. We acknowledge the technical assistance of Ms Amanda Kidsley. SYG was the recipient of a University of Queensland Postgraduate Student scholarship. This material was presented in part as: Guo, S; Platell, J; Brouwers, H; Chapman, T; Cobbold, R; Barrs, V; and Trott, D (2011) Molecular comparison of canine fluoroquinolone resistant phylogenetic group D Escherichia coli isolated from extra-intestinal infections and faeces, In: 4th Symposium on Antimicrobial Resistance in Animals and the Environment. Tours, France, 27–29 June, 2011, Abstract O47, p. 75. This study was supported by an Australian Research Council Linkage Project with Bayer Health Group (grant number LP0776358 ; SYG; HJMB; RNC; DJT) and New South Wales Department of Primary Industries. This material is also based upon work supported by Office of Research and Development, Medical Research Service, Department of Veterans Affairs , grant # 1 I01 CX000192 01 (JRJ).
- Extended-spectrum cephalosporin-resistant
- Extraintestinal pathogenic Escherichia coli
- Phylogenetic group D