Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2017
Publication Date: 3/5/2018
Citation: Sylte, M.J., Inbody, M.H., Johnson, T., Looft, T.P., Line, J.E. 2018. Evaluation of different Campylobacter jejuni isolates to colonize the intestinal tract of commercial turkey poults and selective media for enumeration. Poultry Science. 97(5):1689-1698. https://doi.org/10.3382/ps/pex384.
Interpretive Summary: Campylobacter jejuni is the main bacterial foodborne disease in humans and ingesting contaminated poultry products is the most common route by which humans become exposed. Reducing the amount of Campylobacter in turkeys before they go to slaughter may reduce the amount of Campylobacter in retail poultry products, and lower disease transmission to humans. In order to test strategies to limit Campylobacter in turkeys, research models must be developed using relevant strains of the bacteria for testing in turkeys. We have identified isolates of Campylobacter jejuni that colonize the intestinal tract of turkeys, and identified a specific culture system to precisely determine the number of Campylobacter bacteria in turkey intestinal samples. We also determined the preferred site in the intestinal tract of turkeys where Campylobacter jejuni can be found. Our results provide vital information for scientists to develop and test strategies that reduce the amount of Campylobacter in turkeys, which will promote a safe food supply and benefit consumers of retail turkey products.
Technical Abstract: Consumption of contaminated poultry products is the main source of human campylobacteriosis, which Campylobacter jejuni is responsible for 90 percent of human cases. Although chickens are believed to be a main source of human exposure to C. jejuni, turkey also contributes to cases of human infection. Little is known about the kinetics of C. jejuni intestinal colonization in turkeys, or best selective media for their recovery. Enumeration of C. jejuni from intestinal samples can be challenging because most selective Campylobacter media support the growth of non-Campylobacter organisms. In this study, we sought to identify a) C. jejuni isolates that persistently colonize different compartments of the poult intestinal tract, and b) selective media to enumerate C. jejuni from turkey intestinal samples. Isolates were selected by evaluating motility and in vitro growth. Three week-old poults were orally colonized with C. jejuni isolates NCTC 11168 or NADC 20827 (isolated from a turkey flock). Mock-colonized poults were orally gavaged with uninoculated media. Poults were euthanized at days 3, 7, and 21 post-colonization and direct plated on different selective Campylobacter media (Campy Line agar with sulfamethoxazole (CLA-S), CHROMagar Campylobacter (CAC) and Campy Cefex) for enumeration. Isolates NCTC 11168 and NADC 20827 poorly colonized the distal ileum. Both isolates colonized the colon, but the number of NADC 20827 significantly decreased at day 21. Isolates NCTC 11168 and NADC 20287 persistently colonized the cecum for up to 21 days. There was no significant difference in the Campylobacter amount recovered on CLA-S and CAC. Campy Cefex failed to prevent growth of background microbes to enumerate C. jejuni from turkey samples. Two independent PCR assays (multiplex PCR and qPCR) confirmed that colonies grown on CLA-S or CAC were C. jejuni. Data from this study demonstrated that isolates NCTC 11168 and NADC 20827 persistently colonized the cecum, and CLA-S or CAC were successful to enumerate Campylobacter from intestinal samples. These findings will be useful to evaluate the host-response by C. jejuni in turkeys, and test pre-harvest strategies to reduce its colonization and promote food safety.