Epidemiology and antimicrobial resistance of dominant Salmonella serotypes in Iraqi broiler hatcheries: a comprehensive One Health analysis, Епідеміологія та антимікробна резистентність домінуючих серотипів Salmonella в бройлерних інкубаторах Іраку: комплексний аналіз «Єдиного здоров’я»

<jats:p>Hatcheries are critical points for Salmonella dissemination, and the distribution of its serotypes significantly impacts public health. Despite this global threat, surveillance deficits remain regarding these foodborne pathogens within regional production environments. To address these gaps, this investigation evaluated the occurrence rates, serotype distribution, and antimicrobial resistance profiles of bacterial isolates recovered from commercial broiler production facilities. A multi-facility cross-sectional study was conducted from march to october 2023, encompassing 450 specimens stratified equally into 150 chick cecal contents, 150 eggshells, and 150 worker hand swabs. Microbiological isolation followed international horizontal protocols. Biochemical profiling and slide agglutination methods were employed for serovar identification, while phenotypic susceptibility profiles were determined utilizing the disk diffusion method under clinical laboratory criteria. The analysis detected an overall pathogen prevalence of 8.4 %, corresponding to 38 positive samples out of the 450 tested. Specific isolation rates were distributed across chick ceca at 12.0 % (18 positive samples), eggshells at 7.3 % (11 positive samples), and worker hands at 6.0 % (9 positive samples). Serological typing revealed a predominance of Salmonella Enteritidis at 34.2 % (13 isolates) and Salmonella Kentucky at 26.3 % (10 isolates), each exhibiting alarming multidrug resistance at 38.5 % (5 isolates) and 60.0 % (6 isolates), respectively. Notably, the recovered Salmonella Kentucky strains demonstrated concerning ciprofloxacin resistance at 40.0 % (4 isolates) and cefotaxime resistance at 20.0 % (2 isolates). Both dominant serotypes were consistently recovered from all three sample matrices, demonstrating active circulation within the facilities. In conclusion, commercial broiler facilities serve as reservoirs for highly resistant multidrug-resistant strains. The concurrent presence of a classic egg-associated pandemic variant and an environmentally durable, fluoroquinolone-resistant clone represents a severe threat to food safety. This scenario calls for the immediate implementation of an integrative national health framework incorporating environmental biosecurity measures, strict antimicrobial stewardship, and ongoing systematic monitoring across the production continuum.</jats:p>