Interactions Between Foodborne Bacterial Pathogens and the Microbiome

大多数食源性细菌病原体起源于食用动物的胃肠道，并在生产、加工或分销过程中污染食品。如果农场中细菌病原体的总体丰度减少，将导致食源性疾病负担的减少。在食用动物的胃肠道中，细菌病原体与常驻的非致病菌相互作用，以下简称微生物组。在健康的动物中，胃肠道微生物群是由多样化和动态的细菌群组成的。在这种环境下，对资源的竞争非常激烈。去年，一些肠道细菌病原体已被证明含有一系列负责杀死胃肠道微生物组成员的系统。这些系统为细菌病原体提供了竞争优势，因为杀死竞争对手会增加空间和营养的可用性，以支持它们自己的生长和增殖。拮抗胃肠道微生物群的能力似乎是一些病原体的重要毒力因素，但这还远未被理解。在分子水平上，我们对细菌病原体和微生物群之间相互作用的细节知之甚少。我的研究项目的重点是扩大细菌病原体和食用动物微生物群之间相互作用的基础知识。更彻底地了解病原体/微生物组的相互作用将在几个方面有助于提高食品安全。阐明细菌病原体用来对抗微生物组的机制，并了解这些机制在毒力中的作用，将有助于更准确的风险评估。胃肠道微生物组的组成，换句话说，存在哪些细菌种类和丰度，在个体宿主之间和随着时间的推移会有很大差异。微生物组中的一些细菌似乎具有遗传特征，使它们能够抵抗细菌病原体的杀伤，有些细菌似乎具有对病原体发起致命反击的能力。因此，微生物组组成可能在确定病原体是否将成功建立感染方面具有作用。表征和最终操纵病原体/微生物组相互作用可能提供新的病原体排除策略，同时减少使用治疗性农业抗生素的需求。通过增加对细菌病原体和微生物组之间相互作用的基本知识，我的研究计划将扩大对细菌病原体毒力特性的理解，为农业应用产生新的病原体减少策略，并有助于减轻食源性疾病的负担。

Most foodborne bacterial pathogens originate in the gastrointestinal tract of food-producing animals and contaminate food-products during production, processing, or distribution. If the overall abundance of bacterial pathogens was reduced on the farm it would result in a decrease in the burden of foodborne illness. In the gastrointestinal tract of food-producing animals, bacterial pathogens interact with resident non-pathogenic bacteria, hereafter referred to as the microbiome. In a healthy animal, the gastrointestinal microbiome is composed of a diverse and dynamic bacterial population. Competition for resources in this environment is fierce. In the last year, several enteric bacterial pathogens have been shown to contain a range of systems that are responsible for killing members of the microbiome in the gastrointestinal tract. These systems offer a competitive advantage to bacterial pathogens since killing competitors increases the availability of space and nutrients to support their own growth and proliferation. The ability to antagonize the gastrointestinal microbiome appears to be an important virulence factor for some pathogens, but this is far from being understood. At the molecular level, very little is known about the details of the interactions between bacterial pathogens and the microbiome. The focus of my research program is expanding the fundamental knowledge of the interactions that occur between bacterial pathogens and the microbiome of food-producing animals. A more thorough understanding of pathogen/microbiome interactions will contribute to improving food safety in several ways. Elucidating the mechanisms that bacterial pathogens use to antagonize the microbiome and understanding the role of these mechanisms in virulence will contribute to more accurate risk assessments. The composition of the gastrointestinal microbiome, in other words which bacterial species are present and in what abundance, can vary widely between individual hosts and over time. Some bacterial species in the microbiome appear to have genetic traits that allow them to resist killing by bacterial pathogens, and some appear to have the ability to launch a counter attack that is fatal for the pathogen. Thus, the microbiome composition may have a role in determining if the pathogen will be successful in establishing an infection. Characterizing and ultimately manipulating pathogen/microbiome interactions may offer novel pathogen exclusion strategies while reducing the requirement to use therapeutic agricultural antibiotics. By increasing the fundamental knowledge of the interactions that occur between bacterial pathogens and the microbiome, my research program will broaden the understanding of bacterial pathogen virulence traits, generate novel pathogen reduction strategies for use in agriculture, and contribute to decreasing the burden of foodborne illness.