| Summary: | The practice of feeding dogs raw meat-based diets (RMBDs) is growing in several countries, and the risks associated with the ingestion of pathogenic and antimicrobial-resistant <i>Escherichia coli</i> in dogs fed these diets are largely unknown. We characterized <i>E. coli</i> strains isolated from dogs fed either an RMBD or a conventional dry feed, according to the phylogroup, virulence genes, and antimicrobial susceptibility profiles of the bacteria. Two hundred and sixteen <i>E. coli</i> strains were isolated. Dogs fed RMBDs shed <i>E. coli</i> strains from the phylogroup E more frequently and were positive for the <i>E. coli</i> heat-stable enterotoxin 1-encoding gene. Isolates from RMBD-fed dogs were also frequently positive for multidrug-resistant <i>E. coli</i> isolates including extended-spectrum beta-lactamase (ESBL) producers. Whole-genome sequencing of seven ESBL-producing <i>E. coli</i> strains revealed that they predominantly harbored <i>blaCTX-M-55</i>, and two strains were also positive for the colistin-resistant gene <i>mcr-1</i>. These results suggest that feeding an RMBD can affect the dog’s microbiota, change the frequency of certain phylogroups, and increase the shedding of diarrheagenic <i>E. coli</i>. Also, feeding an RMBD seemed to be linked with the fecal shedding of multidrug-resistant <i>E. coli</i>, including the spread of strains harboring mobilizable colistin resistance and ESBL genes. This finding is of concern for both animal and human health.
|
|---|