Research on the traceability and transmission factors of Salmonella in the broiler production chain: A one health perspective.

Salmonella contamination in chicken is a food safety problem that is widely concerned by all countries around the world. Based on the "One Health" concept, this study systematically collected samples from animals, the environment and workers across 5 stages of the broiler production chain (breeding farms, hatcheries, commercial broiler farms, slaughterhouses, retail) in China, to investigate the prevalence of Salmonella. Meanwhile, based on whole genome sequencing and risk assessment technology, combined with MLST, cgMLST traceability analysis was conducted to clarify the critical control points and transmission factors associated with Salmonella contamination. The results showed that the prevalence rate of Salmonella in the broiler production chain was 10.22% (469/4589). The broiler production chain encompassed 11 serotypes of Salmonella, with S.Enteritidis ran through the entire production chain. Fourteen types of ST were detected from 99 representative strains, and the dominant types were ST11, ST198 and ST1543. ST11 covered the samples from animals, environment and workers in all stages of broider production chain, and was further divided into 14 cgST types. Analysis using @RISK software revealed that the Spearman correlation coefficients for slaughterhouses and hatcheries were 0.54 and 0.26, respectively. These research findings are expected to comprehensively guide chicken production and provide effective strategies for preventing and controlling Salmonella contamination in the broiler production chain.