Building the Tools for Enhanced Waterway Surveillance: Prediction of Antimicrobial‐Resistant Escherichia coli and Their Genes From an Urban River in Aotearoa New Zealand

Urban waterways are reservoirs and vectors of antimicrobial resistance (AMR), yet AMR is not routinely measured alongside faecal indicator bacteria. Using 2 years of data on Escherichia coli and AMR in a New Zealand urban river, we tested how AMR quantification could improve water quality risk assessment. Persistently high frequencies of AMR and pathogenic E. coli sequence types were detected near homes and places of recreation. We measured AMR phenotypes and gene mobilisation by conjugation. We compared phenotyping with genotyping by whole‐genome sequencing to assess whether phenotyping could serve as a proxy for costly sequencing methods. Results suggest that one AMR phenotype could act as a sentinel for less common but problematic resistances, potentially due to plasmid‐based linkage of antibiotic resistance genes or enrichment of clinically relevant sequence types. The study offers a low‐cost water quality monitoring strategy to meet community needs. Widespread adoption of AMR hazard reporting could support the World Health Organization's Sustainable Development Goals and Global Action Plan on AMR.