Fecal carriage of extended-spectrum β-lactamase-, AmpC β-lactamase- and carbapenemase-producing Escherichia coli in stray cats in Italy

The spread of carbapenem-resistant bacteria is a global threat to public health and the role of pets in the rise in antimicrobial resistance is gaining attention worldwide. This study aimed to determine the fecal carriage of extended-spectrum β-lactamase (ESBL)-, AmpC- and carbapenemase (CP)-producing E. coli and associated risk factors in healthy and unhealthy stray cats admitted to the Veterinary Teaching Hospital of Lodi, University of Milan, Italy. Fecal samples collected in, 2020–2022 were microbiologically and molecularly analyzed. Overall, ESBL-/AmpC-/CP-producing E. coli were detected in 18/94 (19.1 %) stray cats. Twelve (12.8 %), 4 (4.3 %) and 7 (7.4 %) stray cats carried ESBL-, AmpC- and CP-producing E. coli phenotypes respectively, supported by the detection of blaCTX-M in all ESBL-producing E. coli, blaCMY-2 in all AmpC-producing E. coli and blaNDM (4/7; 57.1 %) or blaOXA-48 (3/7; 42.9 %) genes in CP-producing E. coli. Multiple combination of resistance genes and phenotypes were detected. MIC results showed that all E. coli were multidrug resistant isolates. Risk factors associated with ESBL-, AmpC- and/or CP-producing E. coli fecal carriage were hospitalization (P < 0.0001), antibiotic treatment during hospitalization (P < 0.0001) and unhealthy status (P < 0.0001). Fecal carriage of CP- producing E. coli is of concern and highlights the need of specific surveillance programs for CP-producing Enterobacteriaceae and antimicrobial stewardship in stray cats to reduce the emergence and spread of resistant bacteria. Limitations of this study suggest a One Health approach to characterize the whole genome of the isolates and the epidemiology of AMR bacteria among stray cats, including additional bacterial species and the environment.