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.)SPP.在包括人类在内的各种物种的肠道上定居。在家禽和猪中，定植一般没有病变和疾病发展。据推测，包括饲料和微生物群组成在内的因素，由物种和/或与免疫功能相关的基因决定的宿主因素可能会改变定植模式。虽然在鸡体内的基因和饲料效应已经得到了更详细的研究，但关于肠道环境对弯曲杆菌在猪和火鸡中定植的影响尚不清楚，尽管这两个物种都可以被认为是重要的宿主。以往的研究表明，空肠弯曲杆菌和大肠埃希氏菌在寄主专一性、定植定位和毒力等方面存在差异。造成这些物种间差异的因素，也可能是物种内菌株之间的差异，目前还没有完全阐明。营养需求的差异可能决定了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、其与微生物区系组成的关系以及随后弯曲杆菌在不同肠段定植的影响，人们知之甚少。本项目将通过比较火鸡和仔猪的大肠埃希氏菌和空肠埃希氏菌的定植模式来研究这些影响因素之间的可能相关性。我们假设这两种弯曲杆菌都会在火鸡和小猪的肠道中定居，但由于营养可获得性和肠道轴上相关微生物群组成的不同，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，并在不同定义的肠道切片上测定以下参数：弯曲杆菌的定植定位(定量)，肠道代谢物的独特空间分布，以及粘膜微生物区系的空间组成。此外，将确定弯曲杆菌从肠道向其他器官(脾、肝)的逃逸，并通过组织学和使用Ussing小室来评估肠道的完整性。在这些体内研究的同时，还将对空肠弯曲菌和大肠杆菌菌株的营养需求进行体外研究。我们期望这项研究将提供一个更深入的洞察力之间的联系，以及随后的代谢和微生物组成之间的关系，以及它的影响弯曲菌在猪和火鸡的定植。这种类型的综合性多学科研究以前从未进行过。我们将提供重要信息，以便随后开发基于平衡方法的新干预策略，将饲料组成方面和微生物区系影响因素(如益生菌)结合起来，这可能有助于降低食物链下游人类感染的风险。

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.