Functional characterisation of a Campylobacter flagellin glycosylation island important in avian adaptation

空肠弯曲杆菌是一种能引起严重食物中毒的细菌。它是世界上最常见的细菌性食物中毒原因，通常是通过处理或食用受污染的家禽，特别是鸡只而感染的。大量的空肠弯曲杆菌可以生活在鸡体内而不会引起任何症状，但我们不知道它们是如何在鸡身上生存的，以及为什么它们会在人身上引起疾病，而不是在禽类身上。这项研究的总体目的是寻找减少食物链中空肠弯曲菌数量的方法，特别是在鸡肉中，以减少食物中毒病例的数量。抗生素耐药性是一个日益严重的问题，因此我们需要通过准确了解细菌的工作原理来找到抗生素的智能替代品。我们希望，如果我们能够了解空肠弯曲菌是如何在鸡身上存活的，我们就可以找到阻止这一过程的方法，也许可以通过给鸟类喂食无害的细菌来阻止致病细菌的存活，或者通过选择细菌不能在其中生存的鸡来阻止。在写这份拨款计划之前，我们比较了91种不同空肠弯曲菌的基因组。这些毒株是从各地的鸡、牛、羊和人以及一般环境中分离出来的。我们发现了一组六个基因，这些基因只存在于来自鸡的菌株中，我们认为这些基因可能是解释细菌如何能够在鸟类体内生存的关键。这是令人兴奋的，因为这是第一次有人发现一个或一组特定来源的空肠弯曲菌菌株的基因。我们发现的基因位于基因组的一个区域内，该区域涉及修改一种特定的蛋白质，称为鞭毛蛋白，这种蛋白质出现在细菌的表面。这些基因通过在鞭毛蛋白中添加糖结构来修饰它。我们知道，为了致病细菌，这种糖的修饰是重要的，因为它影响细菌与他们感染的动物的细胞结合的方式，并影响他们在动物中触发的免疫反应。在拟议的研究计划中，我们对这六个基因(我们称之为cj1321-26)进行了详细的研究，以找出它们到底起什么作用，以及它们是如何帮助细菌在鸡体内生存的。与BB/D521849/1连接。

Campylobacter jejuni is a type of bacterium that causes severe food poisoning. It is the most common cause of bacterial food poisoning in the world and it is usually caught from handling or eating contaminated poultry, especially chickens. Large numbers of C. jejuni bacteria can live inside chickens without causing any symptoms, but we don¿t understand how they survive in chickens, and why they cause disease in people but not in birds. The overall aim of this research is to find ways to reduce the number of C. jejuni bacteria in the food chain, especially in chickens, to reduce the number of cases of food poisoning. Antibiotic resistance is a growing problem, so we need to find clever alternatives to antibiotics by understanding exactly how the bacteria work. We hope that if we can understand how C. jejuni survives in chickens, we can work out how to block the process, perhaps by feeding the birds harmless bacteria that stop the disease-causing ones from surviving, or by selecting chickens that the bacteria aren¿t able to live in. Before writing this grant proposal, we compared the genomes of 91 different strains of C. jejuni. These strains had been isolated from all over the place: chickens, cows, sheep and humans, as well as from the general environment. We found a set of six genes that were only present in the strains that came from chickens, and we think that these genes may be key to explaining how the bacteria are able to survive inside birds. This is exciting, because it is the first time that anyone has found a gene or set of genes that is specific to strains of C. jejuni from one particular source. The genes we found are within a region of the genome that is involved in modifying a particular protein, called flagellin, which appears on the surface of the bacteria. The genes modify the flagellin protein by adding sugar structures to it. We know that in order disease-causing bacteria, this kind of sugar modification is important because it affects they way the bacteria bind to cells in the animals they infect, and it affects the kind of immune response they trigger in the animals. In the proposed programme of research, we went to investigate these six genes (we¿ve called them cj1321-26) in detail, to find out exactly what they do, and just how they help the bacteria to survive in the chicken. Joint with BB/D521849/1.