Antimicrobial resistance in foodborne Escherichia coli and Salmonella spp. from animal-origin foods: Transmission pathways, global surveillance gaps, and alternative therapeutic strategies

Antimicrobial resistance (AMR) in enteric pathogens such as Escherichia coli and Salmonella spp. has emerged as a critical global health challenge affecting both human and animal populations. The widespread use of antibiotics in food-producing animals for therapeutic, prophylactic, and growth-promoting purposes has accelerated the selection and dissemination of resistant bacteria and resistance genes throughout the food chain. Animal-origin foods, including meat, milk, eggs, and fish, serve as important vehicles for the transmission of multidrug-resistant organisms and AMR genes to humans, repre­senting a significant One Health concern. This review provides an overview of the occurrence, molecular mechanisms, and transmission pathways of AMR in E. coli and Salmonella isolated from animal-derived foods. Common resistance determi­nants include β-lactamase genes (blaTEM and blaCTX-M), tetracycline resistance genes (tetA and tetB), and plasmid-mediated quinolone resistance genes, which facilitate horizontal gene transfer through plasmids, integrons, and transposons. Global surveillance reports from World Health Organization’s Global Antimicrobial Resistance Surveillance System, European Food Safety Authority, and World Organization for Animal Health reveal significant regional disparities, with limited monitoring capacity in Central Asia, Africa, and Latin America. Data from Kazakhstan indicate a high prevalence of multidrug-resistant E. coli and Salmonella in poultry, dairy, and cheese products, underscoring the urgent need for harmonized national sur­veillance and risk management strategies. The review also discusses alternative approaches to reduce antibiotic use in livestock production, including bacteriophage therapy, probiotics, phytogenic feed additives, vaccination, and nanotech­nology-based interventions. While these strategies show promising results in laboratory and pilot studies, their practical application remains constrained by regulatory, economic, and field validation challenges. An integrated One Health strategy, combining surveillance, antimicrobial stewardship, and non-antibiotic interventions, is crucial to mitigating the dissemina­tion of AMR along the farm-to-fork continuum. Strengthening laboratory networks, enhancing data sharing, and promoting collaboration among veterinary, environmental, and public health sectors will be crucial to safeguard food safety and global health security. Keywords: animal-origin foods, antimicrobial resistance, antimicrobial stewardship, bacteriophage therapy, Escherichia coli, food safety, foodborne pathogens, Kazakhstan, One Health, probiotics, Salmonella spp., surveillance systems, sustainable livestock production.