First Report of a blaOXA-484-Harbouring Escherichia coli ST167 Isolated from the Urine Sample of a Dog of Italian Origin

Antimicrobial resistance (AMR) is a global threat to both human and animal health. Carbapenems are last-resort antimicrobials used to treat severe infections with multidrug-resistant Gram-negative nosocomial pathogens in humans. Therefore, the dissemination of carbapenemase-producing Enterobacterales (CPE) has emerged as a major concern worldwide. Although carbapenems are not routinely used in veterinary medicine, CPE, including OXA-48-like-producing Escherichia coli, are increasingly being reported in companion animals. We document the first report of E. coli-harbouring blaOXA-484 isolated from a urine sample from a dog with a history of chronic thoracolumbar myelopathy. Using a combined Oxford Nanopore (ONT) long-reads and Illumina short-reads sequencing approach, the isolate was characterized and an IncF plasmid containing blaOXA-484 was reconstructed. The isolate belonged to sequence type (ST)167, which is an emerging high-risk clone frequently reported among human clinical isolates. The blaOXA-484 gene was harboured in a composite transposon bracketed by IS26 identical to that of blaOXA-484 carried on an IncX plasmid pOXA-484-JS316 from a human clinical E. coli ST410 from Germany. The isolation of the epidemic clone ST167 harbouring blaOXA-484 from a canine infection raises the hypothesis of a transmission event between humans and companion animals.