Wild Nutria ( Myocastor coypus ) Is a Potential Reservoir of Carbapenem-Resistant and Zoonotic Aeromonas spp. in Korea

The emergence and spread of antibiotic-resistant spp. is a serious public and animal health concern. Wild animals serve as reservoirs, vectors, and sentinels of these bacteria and can facilitate their transmission to humans and livestock. The nutria ( ), a semi-aquatic rodent, currently is globally considered an invasive alien species that has harmful impacts on natural ecosystems and carries various zoonotic aquatic pathogens. This study aimed to determine the prevalence of antibiotic-resistant zoonotic spp. in wild invasive nutrias captured in Korea during governmental eradication program. Three potential zoonotic spp. ( , , and ) were identified among isolates from nutria. Some strains showed unexpected resistance to fluoroquinolones, third-generation cephalosporins, and carbapenems. In carbapenem-resistant isolates, the gene, which is related to intrinsic resistance of to carbapenems, was identified, and phylogenetic analysis based on this gene revealed the presence of two major groups represented by (including ) and other spp. These results indicate that wild nutrias in Korea are a potential reservoir of zoonotic and antibiotic-resistant spp. that can cause infection and treatment failure in humans. Thus, measures to prevent contact of wild nutrias with livestock and humans are needed.