Making Waves: towards a harmonized approach for monitoring antimicrobial resistance in European surface waters

Antimicrobial resistance (AMR) in aquatic environments is an emerging public health concern, yet environmental surveillance remains underdeveloped compared to human and animal sector. A harmonized European approach to AMR monitoring in aquatic environments is urgently needed due to lack of standardized methods, suitable indicators, reference materials, reporting, and data sharing mechanisms. This perspective paper presents insights from a pilot study, coordinated by the European Environment Agency (EEA), Eionet, and the European Topic Centre Biodiversity and Ecosystems (ETC-BE), aimed at testing the feasibility of harmonized monitoring of AMR in surface waters within regulatory-authority-led water monitoring structures. Ten countries participated, applying harmonized protocols for sampling, culture-based detection, qPCR analysis of antimicrobial resistance genes, and data reporting. The collaboration helped to build capacity and overcome technical barriers. The study demonstrated that harmonized environmental AMR monitoring is feasible and can be implemented consistently across countries and institutions, offering a path to obtaining critical insights into AMR sources, spread, and mitigation strategies. The pilot generated harmonized baseline data, validated methodological choices, and identified key challenges for large-scale implementation. Remaining challenges include the lack of standardized methods, quality criteria, and data infrastructure. Future efforts should focus on defining clear objectives, selecting relevant indicators, establishing environmental thresholds, and building capacity through collaboration. A harmonized European framework would support One Health integration, align with EU water legislation, and contribute to global AMR efforts. The findings underscore the importance of transitioning from fragmented research and ad hoc initiatives to coordinated, routine surveillance of AMR in aquatic environments.