Escherichia coli as a sentinel organism for One Health antimicrobial resistance surveillance: integrating phenotypic, genomic, environmental, and proteomic evidence

Antimicrobial resistance (AMR) surveillance increasingly requires systems that integrate human, animal, food-chain, and environmental data. Escherichia coli (E. coli) is a valuable sentinel organism for this purpose because it is ubiquitous across One Health compartments, easy to isolate and phenotypically test, clinically relevant as both a commensal and an extraintestinal pathogen, and genetically equipped to acquire and disseminate mobile genetic determinants of AMR. This narrative review revises and updates the scientific rationale for using E. coli as an indicator organism in integrated AMR surveillance, with emphasis on current publications and institutional guidance. The evidence supports E. coli as a practical cross-sector indicator, but interpretation requires caution: clonal overlap between sectors is often limited, whereas plasmids, resistance genes, and mobile genetic elements (MGEs) may circulate across ecological boundaries. A robust One Health surveillance system should therefore combine standardized sampling, harmonized antimicrobial susceptibility testing, whole-genome sequencing (WGS), selected long-read sequencing for plasmid reconstruction, environmental and wastewater surveillance, metagenomics, and, for selected questions, proteomic approaches that assess the expression and function of resistance mechanisms. The review proposes a pragmatic framework for surveillance design, interpretation, and action. E. coli should not be treated as a universal proxy for all AMR hazards, but as a high-value sentinel when data are generated and interpreted through explicit epidemiological objectives, comparable methods, and sector-specific metadata. Finally, this review briefly summarizes the challenges confronting AMR surveillance and recommends key actions to overcome them.