Antimicrobial-resistant Escherichia Coli and Salmonella in poultry production and spread and effect in the one health framework.

Antimicrobial resistance in poultry-associated Escherichia coli and Salmonella poses a significant threat to animal, food, and public health, particularly when viewed through the One Health framework. Consider the statistics: global data reveal substantial resistance to tetracyclines (45-92 %), aminopenicillins (38-85 %), sulfonamides (40-78 %), and fluoroquinolones (25-68 %). Additionally, a considerable proportion of isolates (32-74 %) exhibit multidrug resistance. However, the manifestation of this resistance varies widely both between and within countries, influenced by factors such as antimicrobial usage, production scale, biosecurity measures, and the rigor of regulations and surveillance. Notably, the two primary Salmonella serovars-Salmonella Typhimurium and S. Enteritidis, along with increasingly prevalent avian pathogenic E. coli strains, reflect a complex ecological and evolutionary resistance profile characterized by persistence and transmission. Variability in study design, breakpoint criteria, and the use of phenotypic versus genotypic methods contribute to inconsistent findings. Furthermore, geographical differences and limited genomic data hinder accurate estimation of the global burden of antimicrobial resistance. The evolution of resistance occurs through multiple pathways. In high-income countries, robust stewardship programs result in a resistance profile that differs significantly from those in low- and middle-income countries, where antimicrobial use is often less regulated, veterinary services are limited, and prophylactic antimicrobial use is more common. However, resistance is not confined to farms; environmental dissemination through manure, processing, and interspecies transmission of resistance genes to other microbes all contribute to the spread of resistance beyond the farm gate. To address this issue, it is essential to harmonize surveillance systems, improve governance, carefully monitor antimicrobial use, and rationalize economic incentives to achieve stewardship objectives. This includes investing in vaccine development, biosecurity measures, and environmental interventions to reduce the initial need for antimicrobial use. Without a coordinated approach across the entire poultry production chain, poultry will continue to serve as a significant reservoir and vector for the transmission of zoonotic antimicrobial-resistant bacteria.