Raccoons (Procyon lotor) in the Madrid region of Spain are carriers of antimicrobial-resistant Escherichia coli and enteropathogenic E. coli.

The role of wildlife in the epidemiology of antimicrobial resistance is unclear. Raccoons in North America can carry a variety of enteric bacteria, with associated antimicrobial resistance, that could infect humans and livestock. The potential for raccoons to carry these bacteria in Europe, where they are an invasive species, has not been explored. Our objectives were to determine the prevalence of Escherichia coli with associated antimicrobial resistance in raccoons from the Madrid region of Spain and to determine whether they are carriers of potential human pathogens, including verotoxin-producing E. coli (VTEC) and enteropathogenic E. coli (EPEC). In total, we tested 237 E. coli isolates from the faeces of 83 euthanized raccoons for susceptibility to 14 antimicrobial agents and the presence of VTEC and EPEC. Antimicrobial resistance to at least one antimicrobial was detected in the faeces of 51% (42/83; 95% CI, 40.1-61.1) of the raccoons tested. A high percentage of raccoons carried, in their faeces, E. coli isolates resistant to ampicillin (33%), streptomycin (33%), tetracycline (30%), sulphafurazole (31%) and trimethoprim-sulphamethoxazole (23%). We detected one isolate of extended-spectrum β-lactamase-producing E. coli from the faeces of one raccoon. We detected VTEC in the faeces of one raccoon, and EPEC in the faeces of 12% (10/83) of the raccoons. Of the raccoons that carried EPEC in their faeces, 60% (6/10) carried EPEC isolates that exhibited characteristics associated with pathogenicity in humans. Raccoons in Madrid can carry pathogenic and antimicrobial-resistant E. coli in their faeces and may be a risk to public health because of their potential to contaminate food and the environment with their faeces.