Environmental antimicrobial resistance: key reservoirs, surveillance and mitigation under One Health

Environmental antimicrobial resistance (AMR) represents a critical yet understudied dimension within the One Health framework, which emphasizes the interconnections of human, animal, and environmental health. This review systematically examines the sources and key reservoirs of environmental AMR, as well as surveillance and mitigation strategies for environmental resistomes. It begins by discussing the sources of AMR and identifying the primary reservoirs that sustain and disseminate resistance in the environment. Next, it summarizes both phenotypic and genotypic approaches for AMR surveillance and compares their advantages and limitations. This analysis underscores the need for integrated methods that combine phenotypic profiling of resistance capacity with genotypic characterization of antibiotic resistance genes, particularly their mobility and pathogenicity, to enable more accurate monitoring of clinically relevant resistome risks. Furthermore, the review summarizes global source and process control strategies to mitigate environmental AMR. Finally, it offers perspectives on future technological developments to enhance AMR surveillance capacity within complex environmental systems.