Organic acids target bacterial motility to reduce Salmonella enterica serovar Typhimurium attachment to chicken meat during storage

Salmonella, a foodborne pathogen that causes illness worldwide, can utilise its flagellum as a significant virulence factor during infection or colonisation of food matrices. In this study, we have employed a comprehensive approach to evaluate the antimicrobial efficacy of an innovative mixture of organic acids (5% maltodextrin, 1% sodium chloride, 42% citric acid, 18% sodium citrate, 10% silica, 12% malic acid, 9% citrus extract, and 3% olive extract), AuraShield, against Salmonella Typhimurium SE10/72 ability to attach to chicken meat. At sub-inhibitory concentrations (0.25% and 0.45%), AuraShield substantially reduced the bacterium’s ability to form biofilms and its motility, observations that also correlated with lower mRNA levels of the flagellar genes flhD, fliZ, cheA, fliC, and flgM , thereby mechanistically explaining the observed decrease in motility. The incorporation of the antimicrobial mixture in cellulose absorbent pads decreased bacterial survival and adherence to both chicken meat and skin across various storage temperatures (4°C, RT and 37°C), while reducing spoilage markers such as lipid oxidation and total bacterial counts, including E. coli and Lactobacillus . The As-impregnated pads equilibrated the meat pH during the incubation period and did not support Salmonella survival when the pathogen was in direct contact with them. Conclusively, the observed downregulation of key flagellar genes indicates a mechanistic basis for decreased motility and virulence and highlights the potential of AuraShield-impregnated pads as a practical, food-compatible strategy to limit Salmonella persistence and transmission along the poultry production chain and to extend shelf life.