Prevalence and Molecular Characterization of Extended-Spectrum beta-Lactamase Producing Enterobacterales in Healthy Community Dogs in Israel

Antimicrobial resistance is a global problem in human and veterinary medicine. We aimed to investigate extended spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) gut colonization in healthy community dogs in Israel. Methods: Rectal swabs were sampled from 145 healthy dogs, enriched, plated on selective plates, sub-cultured to obtain pure cultures, and ESBL production was confirmed. Bacterial species and antibiotic susceptibility profiles were identified. WGS was performed on all ESBL-PE isolates and their resistomes were identified in-silico. Owners' questioners were collected for risk factor analysis. Results: ESBL-PE gut colonization rate was 6.2% (n=9/145, 95% CI 2.9-11.5). Overall, ten isolates were detected (one dog had two isolates), the main species was Escherichia coli (eight isolates), belonging to diverse phylogenetic groups - B1, A and C. Two iso-lates were identified as Citrobacter braakii, and C. portucalensis. A phylogenetic analysis indicated that all isolates were genetically unrelated and sporadic. Isolates possessed diverse ESBL genes and antibiotic resistance gene content, suggesting independent ESBL spread. In a multivariable risk factor analysis, coprophagia was identified as a risk factor for ESBL-PE gut colonization (p=0.048, aOR=4.408, 95% CI 1.014-19.169). Conclusions: healthy community dogs may be colonized with ESBL-PE MDR strains, some of which were previously reported in humans, that carry wide and diverse resistomes and may serve as a possible source for AMR.