Mechanisms for Vibrio cholerae colonization and pathogenesis in zebrafish

霍乱弧菌在斑马鱼中的定植机制和发病机制

• 批准号: 9924438
• 负责人: JEFFREY H WITHEY
• 金额: $ 38.6万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-05 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9924438
• 关键词: Adherence; Adult; Animal Model; Bacteria; Bacterial Adhesins; Biological; Biology; Cessation of life; Cholera; Developing Countries; Diarrhea; Disease; Disease Outbreaks; Dose; Environment; Feces; Fishes; Gene Expression; Gene Expression Profile; Genes; Global Change; Goals; Hour; Human; In Vitro; Infection; Insecta; Intestines; Knock-out; Knowledge; Laboratories; Life Cycle Stages; Life Style; Measures; Mediating; Modeling; Movement; Mus; Oryctolagus cuniculus; Pathogenesis; Pathogenicity; Pathogenicity Island; Phenotype; Plankton; Play; Process; Production; Research; Role; Severities; Shellfish; Source; Southern Asia; Study models; System; Testing; Toxin; Vibrio cholerae; Virulence Factors; Water; Work; Zebrafish; aquatic organism; combat; diarrheal disease; disease transmission; disorder prevention; egg; gut colonization; gut microbiota; human disease; human pathogen; microbiome; microbiota; new therapeutic target; novel; pandemic disease; pathogen; programs; remediation; targeted treatment; transcriptome sequencing; transmission process; transposon sequencing; water sampling

PROJECT SUMMARY The aquatic bacterium Vibrio cholerae causes human diarrheal disease that can range from mild to deadly. Pandemic O1/O139 strains cause cholera, a potentially deadly disease, whereas non-O1/O139 strains, also known as “environmental” V. cholerae, cause a range of diarrheal diseases from mild to severe. Animal models have been useful in characterizing major V. cholerae virulence factors, but rabbits and mice are not natural V. cholerae hosts and require absent or damaged microbiota to enable colonization. Vertebrate fish are natural V. cholerae hosts and recent work has established zebrafish as a model that recapitulates the entire infectious process in the presence of intact intestinal microbiota. Fish are rapidly colonized by V. cholerae exposure in water, develop diarrhea, excrete large numbers of V. cholerae, and transmit the infection to naïve fish. Because this is a model in a natural host, it presents new opportunities for V. cholerae study that are not possible with mammalian models. However, the V. cholerae factors that act in fish pathogenesis are unknown for both O1 and non-O1/O1319 strains. This proposal will examine the infectious processes used by both O1 and non-O1/O139 V. cholerae and test the following hypotheses: 1) V. cholerae produce specific colonization factors in fish that are also important in human infections. These factors are shared among all V. cholerae strains. This hypothesis will be tested using Tn-Seq to identify genes important for fish colonization. 2) V. cholerae produces factor(s) that directly cause diarrhea. This hypothesis will be tested by knocking out known toxins in each strain and measuring diarrhea. 3) V. cholerae perturbs specific components of the intestinal microbiota, creating a niche for colonization. This hypothesis will be tested by assessing microbiome before and after infection. 4) The type six secretion system (T6SS) is important for competition with intestinal microbiota. This hypothesis will be tested by knocking out T6SS and further identifying T6SS effectors that are important for this competition. 5) V. cholerae excreted by fish are hyperinfectious, as they are in human cholera stool, and this is a likely source of V. cholerae outbreaks. This hypothesis will be tested by comparing infectious doses required for colonization from in vitro grown and fish-passaged V. cholerae. 6) V. cholerae shifts its gene expression program prior to host escape to enable transmission and contribute to hyperinfectivity. This hypothesis will be tested using RNA-Seq to determine global changes in gene expression between in vitro grown, actively colonizing, and excreted V. cholerae. Completion of the proposed work, using zebrafish as a natural V. cholerae host model, will significantly advance our understanding of the environmental lifestyle of V. cholerae in a natural reservoir, the requirements for V. cholerae to become a pathogen, and should uncover new targets for therapeutics, environmental remediation, and disease prevention. The long term goal of this project is to use the zebrafish model to better understand V. cholerae pathogenesis in humans and identify new strategies to combat V. cholerae disease and transmission. .

项目摘要 水生细菌霍乱弧菌导致人类肠道疾病，范围从轻微到致命。 流行性O 1/O 139菌株引起霍乱，这是一种潜在的致命疾病，而非O 1/O 139菌株也 被称为“环境”霍乱弧菌，引起一系列从轻微到严重的肠道疾病。动物模型 在描述霍乱弧菌的主要毒力因子方面是有用的，但兔和小鼠不是天然的霍乱弧菌。 霍乱宿主，需要缺乏或受损的微生物群才能定植。脊椎鱼类是天然的V。 霍乱宿主和最近的工作已经建立了斑马鱼作为一个模型，重演了整个传染性 在完整的肠道微生物群的存在下进行。鱼类在暴露于霍乱弧菌后迅速定殖， 水，发展腹泻，排泄大量的霍乱弧菌，并将感染传播给幼稚的鱼。 因为这是一个自然宿主的模型，它为霍乱弧菌的研究提供了新的机会， 对于哺乳动物模型来说是可能的。然而，在鱼类致病中起作用的霍乱弧菌因子是未知的 O 1和非O 1/O 1319菌株。该提案将研究O 1和O2使用的感染过程， 和非O 1/O 139型霍乱弧菌，并验证了以下假设：1）霍乱弧菌产生特异性定殖 鱼类中的因子在人类感染中也很重要。这些因素在所有霍乱弧菌中共享 菌株这一假设将使用Tn-Seq进行测试，以确定对鱼类定殖重要的基因。2)诉 霍乱产生直接引起腹泻的因子。这一假设将通过敲除已知的 每种菌株的毒素和测量腹泻。3)霍乱弧菌干扰肠道的特定成分， 微生物群，为殖民创造一个利基。这一假设将通过评估微生物组进行测试， 感染后。4)第六型分泌系统（T6 SS）在与肠道竞争中起重要作用。 微生物群这一假设将通过敲除T6 SS并进一步鉴定T6 SS效应子来检验， 对这次比赛很重要。5)鱼类分泌的霍乱弧菌具有高度传染性，就像人类霍乱一样 粪便，这是霍乱弧菌爆发的可能来源。这一假设将通过比较 体外生长和鱼传代的霍乱弧菌定殖所需的感染剂量。6)霍乱弧菌 在宿主逃逸之前改变其基因表达程序，以使其能够传播并有助于 高传染性这一假设将使用RNA-Seq进行检验，以确定基因表达的总体变化 在体外生长、活跃定植和排泄的霍乱弧菌之间。完成拟议的工作，使用 斑马鱼作为一种天然的霍乱弧菌宿主模型，将大大推进我们对霍乱弧菌的认识。 环境生活方式的霍乱弧菌在天然水库，要求霍乱弧菌成为一个 病原体，并应发现新的治疗目标，环境修复和疾病 预防该项目的长期目标是使用斑马鱼模型更好地了解霍乱弧菌 在人类的发病机制，并确定新的战略，以打击霍乱弧菌疾病和传播。 .