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Published on: December 23, 2022
Clonal Diversity of Extraintestinal Pathogenic Escherichia coli Strains Isolated from Canine Urinary Tract Infections
Luciana Sartori1, João Pedro Rueda Furlan2, Fábio Parra Sellera3,4
1Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, Brazil.
Background/Objectives:
Extraintestinal pathogenic Escherichia coli (ExPEC) strains, particularly those belonging to phylogenetic group B2, are clinically significant due to their frequent involvement in urinary tract infections (UTIs) and display antimicrobial resistance profiles. While the association of phylogroup B2 E. coli with human urinary tract infections is well established, the growing number of reports of ExPEC strains in canine UTIs highlights their clinical relevance in small animal medicine and raises concerns about their potential role in zoonotic transmission. This study investigated the microbiological and genomic features of E. coli strains isolated from dogs with UTIs in São Paulo, Brazil.
Methods:
Between March and May 2023, a total of 60 E. coli strains from canine UTIs were screened for antimicrobial susceptibility and phylotyping. Accordingly, four strains (6.6%) were identified as multidrug-resistant (MDR) or belonging to phylogroup B2 and, therefore, were submitted for characterization by whole-genome sequencing.
Results:
The four E. coli strains exhibited diverse antimicrobial resistance profiles, including resistance to third- and fourth-generation cephalosporins and fluoroquinolones. Phylogenetic groups B1, B2, and G, and sequence types (ST) 73, ST224, ST1193, and ST12960 were identified. The resistome included clinically important β-lactam resistance genes, such as blaCTX-M-55 and blaCMY-2, as well as mutations in the quinolone-resistance-determining region. Virulence factors associated with ExPEC pathogenesis, including adhesion, iron acquisition, immune evasion, and toxin, were detected. Plasmid sequences were identified as carrying antimicrobial resistance and virulence genes, highlighting the potential for horizontal gene transfer.
Conclusions:
Our findings underscore the importance of genomic surveillance in companion animals to better understand the epidemiology of ExPEC strains and monitor the spread of MDR strains.
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