Inhibition and Interactions of Campylobacter jejuni from Broiler Chicken Houses with Organic Acids

is a bacterium that causes major diarrheal disease worldwide and is also one of the top five foodborne pathogens encountered in the United States. Poultry is a major source of , and a high-risk factor for contracting campylobacteriosis. Organic acids are used in the United States during food animal processing for removal of bacterial contamination from animal carcasses. Six organic acids were evaluated in inhibition studies of 96 strains obtained from shoe covers used in broiler chicken houses at different poultry farms in several states by determining the susceptibilities of the strains, along with the pH values at the molar minimum inhibitory concentrations (MIC s). The undissociated and dissociated organic acid concentrations were calculated at the MIC s with the Henderson-Hasselbalch equation. The results for the 96 strains were treated similarly for each different organic acid. inhibition did correlate with the dissociated organic acids, but did not correlate with pH or with the undissociated organic acids. When the concentrations of dissociated organic acids decreased, the strains were not disinfected. A carcass wash using organic acids should have the concentration of dissociated acid species carefully controlled. It is suggested to maintain a dissociated acid concentration for propionic, l-lactic, formic, citric, butyric, and acetic acids at 24, 40, 36, 21, 23, and 25 mM, respectively, and at these dissociated organic acid levels an acid wash would be expected to remove or inhibit 97% or more of the bacteria studied here. However, studies must be undertaken to confirm that the suggested concentrations of dissociated organic acids are adequate to remove bacteria in the field vs. the laboratory. Due to propionate, l-lactate, formate, butyrate, and acetate being utilized by , these organic acids may not be appropriate for use as a carcass wash to remove surface contamination. Of all tested organic acids, dissociated citric acid was the most efficient at inhibiting .