Abstract
This article details the identification and biological characterization of three Salmonella isolates recovered from wild gadwalls (Anas strepera) in the Lake Balkhash basin (Jambyl region). The research is necessitated by the prevalence of Salmonellosis of Waterfowl (SW) in agricultural settings and the relative lack of surveillance data regarding infection dynamics in wild populations. SW remains a critical factor in poultry mortality, particularly affecting young birds between 5 and 45 days of age, while inducing chronic shedding in adults. Within the "One Health" framework—integrating animal, human, and environmental health—the interspecies transmission of pathogens is a significant biological challenge. Factors such as the lack of migratory monitoring, the spread of antibiotic-resistant strains, and environmental contamination of water bodies exacerbate the epizootic situation. The objective of this study was to diagnose the infection in wild avian species, isolate the pathogen, and determine its antibiotic susceptibility profile. The experimental framework employed bacteriological, serological, and biochemical analysis methods. Out of 30 wild duck specimens examined, three individuals tested positive for the SW pathogen. These findings highlight the role of wild waterfowl as reservoirs for Salmonella, posing a potential risk of foodborne toxicoinfections in humans. The study emphasizes the necessity for integrated monitoring systems to mitigate the spread of infection between wild and domestic ecosystems.