Genetic analysis of beneficial bacterial colonization

有益细菌定植的遗传分析

• 批准号: 10555034
• 负责人: Mark J Mandel
• 金额: $ 40.81万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-08 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10555034
• 关键词: Address; Animals; Bacteria; Bacterial Genes; Behavior; Biological Models; Cells; Chemicals; Communication; Environment; Exclusion; Goals; Hour; Image; Immune; Individual; Infection; Investigation; Laboratories; Laboratory Study; Life Style; Ligands; Light; Microbe; Microbial Biofilms; Modeling; Molecular; Organ; Play; Probiotics; Process; Proteins; RNA-Binding Proteins; Reproducibility; Route; Seawater; Signal Pathway; Signal Transduction; Site; Specificity; Squid; System; Therapeutic Intervention; V. fischeri-squid system; Vibrio fischeri; Work; antimicrobial; beneficial microorganism; genetic analysis; genetic approach; genetic manipulation; host colonization; host-microbe interactions; microbiome; novel; pathogenic microbe; protein function; small molecule; success; symbiont; transmission process

PROJECT SUMMARY The objective of my laboratory is to characterize how molecular communication between bacteria and their animal hosts leads to specific and reproducible colonization. To accomplish this goal, the laboratory studies the Vibrio fischeri-squid system, in which the animal’s “light organ” is colonized exclusively by one bacterial species. This system is advantageous because bacteria colonize through the natural route of infection, all animals are colonized within three hours of bacterial inoculation into the seawater, the bacteria can be subject to detailed genetic manipulation, the precise site of infection can be imaged directly in the live animal host, and chemical analysis of the animal host enables detailed molecular investigations. Focusing on how squid are reproducibly colonized by the specific symbiont, to the exclusion of the millions of competing bacteria in seawater, has revealed key roles for bacterial aggregation and biofilm formation in promoting specific host- microbe interactions. Questions that our group is asking include: (1) How does a symbiont regulate a beneficial biofilm? Biofilms provide microbes with a protected environment in which they can act collectively and resist innate immune insults and antimicrobial compounds. V. fischeri elaboration of a symbiotic biofilm is required for entry into the host, providing an opportunity to study this process in the context of a natural host colonization model. Our past work identified BinK as a key negative regulator of biofilm formation and the planktonic-to-biofilm transition in the host. In this study, we examine how BinK interprets signals from the host and how that information is transmitted to V. fischeri. We examine mechanisms of signal transduction and seek to identify and characterize a ligand that regulates BinK activity. (2) What novel bacterial factors play critical functions in colonization processes? We have had success in applying global genetic approaches to identify bacterial colonization factors in V. fischeri. With a focus on novel and understudied bacterial genes for which the V. fischeri-squid system has the potential to elucidate protein functions, we identified a protein that has a substantial impact on biofilm formation and squid colonization. The protein is annotated as a putative RNA-binding protein, and we will characterize the molecular mechanisms by which this protein acts and determine how it impacts symbiotic biofilm formation. (3) How do small molecules influence microbiome specificity and colonization? We have begun to identify compounds that are present in the host and that are co-regulated with symbiotic behaviors. We will integrate genetic approaches to elucidate signaling pathways in the context of host colonization. A major strength of the V. fischeri-squid system is the ability to interrogate bacterial behavior in the intact animal host, and completion of these projects will enable a deeper understanding of the mechanisms underlying animal colonization by beneficial microbes.

项目概要 我实验室的目标是表征细菌及其细菌之间的分子通讯方式 为了实现这一目标，实验室对动物宿主进行了研究。 费氏弧菌-鱿鱼系统，其中动物的“发光器官”专门由一种细菌定殖 该系统是有利的，因为细菌通过自然感染途径定植。 动物在细菌接种到海水中后三小时内定殖，细菌可以受到影响 通过详细的基因操作，可以直接在活体动物宿主中对感染的精确部位进行成像，并且 对动物宿主的化学分析可以对鱿鱼进行详细的分子研究。 特定共生体可重复地定植，排除了数百万种竞争性细菌 海水，揭示了细菌聚集和生物膜形成在促进特定宿主的关键作用 我们小组提出的问题包括：（1）共生体如何调节微生物的相互作用。 有益的生物膜？生物膜为微生物提供了一个可以集体行动的受保护环境。 并抵抗先天免疫损伤和抗菌化合物 V. fischeri 共生生物膜的阐述。 进入宿主所需的，提供了在自然宿主的背景下研究这一过程的机会 我们过去的工作将 BinK 确定为生物膜形成和定植的关键负调节因子。 在这项研究中，我们研究了 BinK 如何解释来自宿主的信号。 以及该信息如何传递给 V. fischeri 我们检查信号转导机制并寻找。 (2) 哪些新的细菌因素起着关键作用 我们已经成功地将全球遗传方法应用于 鉴定 V. fischeri 中的细菌定植因子，重点是新的和尚未研究的细菌基因。 由于 V. fischeri-squid 系统具有阐明蛋白质功能的潜力，我们鉴定了一种蛋白质 对生物膜形成和鱿鱼定殖有重大影响 该蛋白质被注释为假定的。 RNA 结合蛋白，我们将描述该蛋白作用的分子机制并 确定它如何影响共生生物膜的形成 (3) 小分子如何影响微生物组。 特异性和定殖？我们已经开始鉴定存在于宿主中的化合物 我们将整合遗传方法来阐明信号通路。 V. fischeri-鱿鱼系统的一个主要优势是询问宿主的能力。 完整动物宿主中的细菌行为，以及这些项目的完成将能够更深入地研究 了解有益微生物在动物定植的机制。