Detection of OXA-244 – Carbapenemase - Producing Escherichia coli in companion animals: An emerging resistance threat

Resumo

Introduction: The emergence and spread of extended-spectrum beta-lactamases (ESBL), plasmid-mediated AmpC (pAmpC), and carbapenemases pose a critical threat to animal, human, and environmental health, underscoring the urgent need for surveillance strategies. In this study, we propose to evaluate and characterize the presence of ESBL/pAmpC- and carbapenemases-producing Enterobacterales in fecal samples from companion animals undergoing clean orthopedic surgery.
Material and methods: In 2023, fecal swab samples from companion animals (n=64) undergoing clean orthopedic surgery at Veterinary Hospitals in the Lisbon area were collected and inoculated on MacConkey agar plates supplemented with 1.5 μg/mL cefotaxime and 1.0 μg/mL meropenem. β-lactamases genes were detected by PCR and Sanger sequencing. Antimicrobial susceptibility testing was performed using disk diffusion according to CLSI guidelines, and phylogenetic typing of Escherichia coli isolates was conducted using PCR. WGS was performed for carbapenemase-producing strains (Oxford Nanopore Technologies (ONT), United Kingdom).
Results: ESBL/AmpC-producing Enterobacterales were detected in 20.3% (13/69) of the companion animals. Of these, 84.6% (11/13) were identified as Escherichia coli, mainly from phylogenetic group B1. Furthermore, 46.1% (6/13) of the Enterobacterales isolates were multidrug resistant (MDR). The blaCTX-M-15 gene was the most common. One E. coli strain belonging to ST4981 and serotyping O101:H9, also exhibited resistance to carbapenems and harbored the blaOXA-244 gene.
Conclusions: To our best knowledge, this is the first report of a companion animal colonized with an OXA–244–producing E. coli. These results underscore the importance of early detection and effective infection control strategies. This study highlights the critical need for a One Health approach to mitigate the spread of carbapenems antimicrobial resistance.
Keywords: Escherichia coli, ESBL, Carbapenemases, dogs, One-health
Acknowledgments: This work was supported by a Project funded by FMV-ULusófona/ILIND.