Antibacterial effect of Trans-cinnamaldehyde on Salmonella enteritidis and Campylobacter jejuni in chicken drinking water

Salmonella Enteritidis and Campylobacter jejuni are 2 major foodborne pathogens in the United States, estimated to cause more than 3 million cases of human illness annually. Chickens are the natural hosts of these bacteria, and their drinking water can be a source of S. Enteritidis and C, jejuni, contributing to the colonization of birds. In this study, trans-cinnamaldehyde (TC), a natural, generally recognized as safe ingredient in cinnamon oil was evaluated for its efficacy to inactivate S. Enteritidis and C. jejuni in the drinking water of chickens. Well water containing 0, 0.016, 0.03, and 0.06% TC was inoculated with a 5-strain mixture of S. Enteritidis or C. jejuni (∼6 log₁₀ cells/mL). Water samples containing 1% chicken feces or feed were also included. The samples were incubated at 12.5 or 25°C for 7 d and analyzed for bacterial populations on d 0, 1, 3, 5, and 7. Duplicate samples of treatments and control were included, and the study was replicated 3 times. Trans-cinnamaldehyde at 0.06% inactivated Salmonella completely after 24 h in water with 1% feces at both temperatures. In water containing 1% feed, TC (0.06%) reduced S. Enteritidis to undetectable levels after 3 d at 12.5°C or 7 d at 25°C. Presence of feed or feces in water reduced the antibacterial effect (P < 0.001) of TC. The effect of TC on C. jejuni was more pronounced than that on S. Enteritidis. The TC at 0.06% completely inactivated the pathogen after 1 d of incubation at both temperatures. The presence of feces or feed did not have any effect (P > 0.001) on the antibacterial property of TC on C. jejuni. Results indicate that TC is effective in killing S. Enteritidis and C. jejuni in chicken drinking water and may decrease the likelihood that water will contribute to colonization of chickens by these pathogens.