Ability of Garlic and Ginger Oil to Reduce Salmonella in Post-Harvest Poultry

SIMPLE SUMMARY: Reducing Salmonella contamination of poultry meat is vital to reducing the incidence of human Salmonella infections in the United States. While individual birds can carry Salmonella, poultry meat often becomes contaminated in the processing plant where a high risk of cross contamination also exists. Currently, chemicals such as peracetic acid are used during processing to kill microbes and prevent contamination. However, consumers are increasingly weary of chemical use with interest in natural alternatives growing. Garlic and ginger oils have proven antimicrobial activity and possess many benefits for human health. Therefore, we sought to determine the ability of garlic and ginger to reduce Salmonella in the processing environment. A combination of both oils reduced Salmonella on chicken skin by up to 99% and prevented Salmonella growth in the simulated scalding tank environment. Investigation into the antibacterial mode-of-action revealed a potential of the oils to inhibit the ability of Salmonella to adhere to host cells. In total, this data demonstrates the potential of garlic and ginger oil to serve as a natural alternative to reduce Salmonella prevalence and cross-contamination in the processing plant. ABSTRACT: Approximately 1.35 million human salmonellosis cases are reported in the United States every year, resulting in over 26,000 hospitalizations and 400 deaths. Consumption of contaminated poultry products is one of the leading causes of human salmonellosis. Poultry meat becomes contaminated when feces from an infected bird comes into contact with the carcass during processing. Additional carcasses can then become cross-contaminated along the processing line. While chemicals such as peracetic acid are currently used to kill microbes such as Salmonella, consumers are increasingly calling for more natural alternatives. Our objective for this study was to determine the ability of the phytochemicals garlic and ginger oil to reduce Salmonella prevalence in the processing environment. In a simulated scalding tank environment, dipping contaminated chicken skin samples in a solution containing both garlic and ginger oil reduced Salmonella by up to 2 log CFU. Furthermore, the oils prevented Salmonella growth in the tank solution. The mechanism of action of garlic and ginger was evaluated using the sub-inhibitory concentration of each oil individually. While both were found to decrease autoinducer-2 (AI-2) levels, no effect was seen on expression of 10 genes involved in Salmonella virulence and survival. In total, this work demonstrates the potential of garlic and ginger to reduce Salmonella prevalence in the post-harvest environment. However, more work remains to be done to understand the mechanism of action.