Detection of Campylobacter jejuni liver dissemination in experimentally colonized turkey poults

Abstract Consumption of contaminated poultry products, including chicken livers, is the main source of human campylobacteriosis and approximately 90% of human cases are caused by Campylobacter jejuni subsp. jejuni (C. jejuni). Recent culinary trends that favor undercooked chicken livers may be responsible for outbreaks. Turkey is an emerging human protein source, and poultry livers are commonly prepared into popular cuisine such as pâte. The mechanism of how Campylobacter disseminates to poultry liver tissue is unknown. We have previously demonstrated that certain strains of C. jejuni persistently colonize turkeys with the highest density in the ceca. Whether C. jejuni disseminates to the liver of turkeys following intestinal colonization is unknown. In this study, 45 day of hatch turkey poults were co-housed for 30 days. Five poults were euthanized to screen for Campylobacter colonization, and were free of detectable Campylobacter. The remaining 40 poults were randomly split into two rooms, with 20 per room. At 35 days of age, poults were inoculated by oral gavage with 1x106 colony forming units of C. jejuni isolate NCTC 11168 or mock-inoculated with sterile medium. Ten poults from each room were euthanized at 7 and 14 days post-inoculation (dpi), and cecal contents and livers were cultured and/or enriched for Campylobacter. Livers were harvested aseptically. The ceca of C. jejuni inoculated poults were highly colonized at 7 and 14 dpi with approximately 108 cfu/ml of cecal contents. At 7 and 14 dpi, 3/10 and 5/10 liver samples were positive for C. jejuni culture (8.6x103 cfu/g of liver ± 4.43 x103 and 5.10x103 cfu/g of liver ± 1.74 x103), respectively. At 14 dpi, liver samples were cultured by enrichment, and 6/10 were positive for Campylobacter. Some liver samples may be below the limit of detection for direct plate culturing. These data determined that turkey liver is a potential reservoir of C. jejuni following intestinal colonization, and identified a potential food safety consideration when turkey liver is prepared for human or pet food consumption.