Antimicrobial resistance, virulence factors and phylogenetic analysis of canine Escherichia coli causing cystitis and comparison with human uropathogenic

Abstract

Escherichia coli (E. coli) are the main pathogen causing urinary tract infection (UTI), both in humans and animals worldwide and usually phylogenetic group (PG) B2 and D are known to have more virulence factors (VFs) and less antimicrobial resistance (AR)-determinant genes than group A and B1 in human community, but the correlations between PGs, VFs, and AR of uropathogenic Escherichia coli (UPEC) strains isolated from cystitis have not been conducted in small animal strains. A total of 49 E. coli strains were isolated from canine cystitis patients. For all strains, PGs and VFs were analyzed by polymerase chain reaction (PCR), and the AR was screened by disk diffusion tests. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to compare canine UPEC and human ST131 strains. PG B2 was the most prevalent group (25/49, 51.0%) and significantly associated with VFs of cnf (Extraintestinal pathogenicity), papA (fimbriae), focG (fimbriae), cvaC (colicin V), ibeA (brain endothelium gene), kpsMPIII (capsule synthesis gene) and PAI (pathogenicity associated island). PG D was associated with fyuA (yersiniabactin). There was no significantly different distribution between PGs and AR, with the exception that PG B2 was associated with quinolones susceptibility. Interestingly, 40.8% of isolates showed resistance to trimethoprim/ sulfamethoxazole, and 63.3% and 55.1% showed resistance to quinolones, nalidixic acid and ciprofloxacin respectively. Human UPEC ST131 and canine UPEC strains were included in different PFGE groups. PGs of canine E. coli strains causing cystitis were associated with several VFs and quinolones resistance. Human UPEC ST131 isolates displayed similar PFGE patterns and clustered separately from canine isolates.