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

弯曲杆菌（C.）在包括人类在内的多种物种的肠道中定植。在家禽和猪中，定植通常发生在没有损伤和疾病发展的情况下。据推测，饲料和微生物组组成、由物种决定的宿主因素和/或与免疫功能相关的基因型等因素可能会改变定植模式。虽然对鸡的基因型和饲料效应进行了更详细的研究，但肠道环境对弯曲杆菌在猪和火鸡中的定植的影响尚不清楚，尽管这两种物种都被认为是重要的宿主。以前的研究表明，两种弯曲杆菌，C. coli和C. jejuni，在宿主特异性、定殖定位和毒力方面各不相同。造成这些物种之间差异的因素，可能也包括物种内菌株之间的差异，尚未完全阐明。营养需求的差异可能决定某些弯曲杆菌菌株利用肠道生态位的机会。关于营养可利用性的差异，其与微生物群组成的关系以及随后弯曲杆菌在不同肠道部分定殖的影响，我们知之甚少。本项目将通过比较大肠杆菌和空肠杆菌在火鸡和仔猪之间的定殖模式，探讨这些影响因素之间可能存在的相关性。我们假设这两种弯曲杆菌都将在火鸡和仔猪的肠道中定植，但由于营养可利用性和肠道轴上相关微生物群组成的差异，它们将使用不同的生态位。我们将用其中一种菌株单独或联合接种火鸡和仔猪，并确定不同肠道部分的以下参数：弯曲杆菌定植的定位（定量），肠道代谢物的独特空间分布，以及粘膜微生物群的空间组成。此外，将确定弯曲杆菌从肠道向其他器官（脾脏、肝脏）的逃避情况，并使用乌辛室从组织学上评估肠道完整性。这些体内研究将伴随对空肠梭菌和大肠杆菌菌株营养需求的体外研究。我们希望这项研究能够更深入地了解营养有效性、代谢和微生物群组成之间的关系，以及弯曲杆菌在猪和火鸡中定植的影响。这种综合性的多学科研究以前还没有进行过。我们将提供重要的信息，以基于平衡的方法开发新的干预策略，结合饲料成分方面和益生菌等微生物群影响因素，这可能有助于降低人类在食物链中感染的风险。

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.