Reservoirs of antimicrobial resistance in the context of One Health

Publication Summary

In relation to infectious disease, One Health represents a transdisciplinary approach that shifts the focus from disease treatment and control to disease prevention and surveillance. This review highlights the latest insights into the emergence and spread of antimicrobial resistance (AMR) from the One Health perspective, considering humans, animals, and the environment. A major challenge remaining for most One Health studies is attributing the directionality of transmission of antimicrobial resistance genes (ARGs) between different metagenomes.

Who this is for

• One Health researchers
• Policymakers

Key findings

• In the context of One Health, natural microbial communities (or microbiomes) have an important role in the dissemination of AMR even when most of the microorganisms constituting the microbiome are considered commensals. 
• The role of human-influenced environments in sustaining and disseminating AMR is largely unexplored, although the environment as a reservoir cannot be discounted and recent evidence suggests that ARGs in environmental bacteria can be rapidly acquired by human-associated and pathogenic bacteria.
• Nonpathogenic bacteria that are regularly excluded from surveillance programs may serve as a reservoir for AMR along food supply chains, underscoring the need for more comprehensive analyses and monitoring of food animal reservoirs of AMR (including seafood).
• Many metagenomic studies still target only one side of the One Health triad, for example human-animal, animal-environment, or environment-human.
• There is a need for more in-depth characterization of AMR transmission mechanisms, including methods to determine and classify transmission. Approaches should combine metagenomic data analysis (including phylogenetic analysis) with epidemiology and time series information.
• Better understanding of the directionality of AMR transmission between human, animal, and environmental reservoirs can help improve management of reservoirs, especially in terms of anthropogenic effects, and antibiotic stewardship practices.