Campylobacter spp. colonization of pigs and turkeys: Investigations on the impact of species-associated factors and availability of intestinal nutrients

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Campylobacter (C.) spp. colonize the gut of a variety of species including humans. In poultry and pigs colonization occurs generally without lesion and disease development. It is speculated that factors including feed and microbiome composition, host factors determined by species and/or genotype associated with immune functions may modify the colonization pattern. While in chickens genotype and feed effects have been studied in more detail, nothing is known about the influence of the intestinal environment on Campylobacter colonization in pigs and turkeys, although both species can be considered as important reservoirs. Previously it was demonstrated that both Campylobacter species, C. coli and C. jejuni, vary in their host specificity, localization of colonization, and virulence. The factors contributing to these differences between species but possibly also between strains within the species have not been fully elucidated yet. Differences in nutrient requirements may determine the chance of certain Campylobacter strains to use ecological niches in the gut. Very little is known about the differences in nutrient availability, its association with microbiota composition and subsequently the influence of Campylobacter colonization in different intestinal sections. This project will investigate the possible correlation between these influencing factors by comparing C. coli and C. jejuni colonization pattern between turkeys and piglets. We hypothesize that both Campylobacter species will colonize the gut of turkeys and piglets but they will use different niches due to differences in nutrient availability and associated microbiota composition along the gut axis. We will inoculate turkeys as well as piglets either with one of the strains alone or in combination and determine the following parameters in different defined gut sections: Localization of colonization of Campylobacter (quantitatively), distinctive spatial distribution of intestinal metabolites, and spatial composition of the mucosal microbiota. In addition evasion of Campylobacter from the gut to other organs (spleen, liver) will be determined and the gut integrity will be evaluated histologically and by using the Ussing chamber. These in vivo investigations will be accompanied by in vitro investigations on the nutrient requirements of strains of C. jejuni and C. coli. We expect that this study will provide a deeper insight in the association between nutrient availability, and subsequently metabolom and microbiota composition and its effect of Campylobacter colonization in pigs and turkeys. This type of a comprehensive multidisciplinary study has not been conducted before. We will deliver important information to subsequently develop new intervention strategies based on a balanced approach combining feed composition aspects and microbiota influencing factors such as probiotics, which may help to reduce the risk of human infections down the food chain.