Antimicrobial Resistance in E. coli and Salmonella spp. Across Romanian Animal–Food–Environment Interfaces: Current Evidence and One Health Knowledge Gaps

Antimicrobial resistance (AMR) is an important One Health challenge, yet evidence on resistant Escherichia coli and Salmonella spp. in Romania is dispersed across animal species, food matrices, environmental compartments, and surveillance systems. This comprehensive narrative review synthesizes and critically evaluates evidence across animal–food–environment interfaces and places it in the context of broader European AMR patterns. Particular attention is given to isolate origin, resistance phenotypes, multidrug resistance, major resistance determinants, molecular epidemiology, and the strength of evidence supporting cross-sector connections. Studies most frequently addressed poultry and swine, where resistance to ampicillin, fluoroquinolones, sulfonamides, and tetracyclines was repeatedly reported, together with extended-spectrum cephalosporin resistance, particularly in E. coli. Evidence from cattle, foods of animal origin, companion animals, wildlife, wastewater, and aquatic environments shows that resistant bacteria and antimicrobial resistance genes occur across multiple compartments. Substantial heterogeneity in sampling design, susceptibility testing, and molecular characterization limits direct comparison between studies, while epidemiologically linked investigations and whole-genome sequencing across connected reservoirs remain uncommon. Priorities include more standardized cross-sector surveillance, stronger environmental monitoring, expanded genomic epidemiology, improved data interoperability, and continued antimicrobial stewardship. By integrating fragmented national evidence, this review identifies both well-characterized sectors and interfaces where important evidence gaps remain.