Current understanding and knowledge gaps regarding wildlife as reservoirs of antimicrobial resistance

Antimicrobial resistance (AMR) is a serious health issue shared across all One Health domains. Wildlife species represent a key intersection of the animal and environmental domains. They are a relevant but understudied reservoir and route of spread for AMR throughout the environment. Most wildlife AMR research thus far has focused on avian species, terrestrial mammals, and a selection of aquatic and marine species. Pathogens often identified in terrestrial wildlife include enteric zoonotic organisms such as Eschericia coli and Salmonella spp, in addition to nonenterics such as Staphylococci. Resistances have been commonly identified to antimicrobials important in veterinary and human medicine, including β-lactams, tetracyclines, aminoglycosides, and macrolides. Our emerging understanding of the dynamics of AMR distribution across life on Earth provides further opportunities for us to assess the risk it poses to veterinary and human health. Future work will require prioritizing which wildlife most exacerbates and indicates AMR in domestic animals. However, decreasing prices and increasing ease for metagenomic sequencing allows for synergies with expanding wildlife viral disease surveillance. Improved understanding of how wildlife impacts veterinary and human healthcare may increase opportunities for related research funding and global equity in such research. The companion Currents in One Health article by Vezeau and Kahn, JAVMA, June 2024, addresses in further detail the routes of spread of AMR across different animal populations and actions that can be taken to mitigate AMR with special consideration for wildlife sources.