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 水生细菌弧菌霍乱会引起人类腹泻病，可能从轻度到致命。 大流行O1/O139菌株会导致霍乱，一种潜在的致命疾病，而非O1/O139菌株也会引起霍乱 被称为“环境” V.霍乱，引起一系列腹泻疾病，从轻度到重度。动物模型 在表征主要的霍乱病毒因素方面非常有用，但是兔子和小鼠不是天然V。 霍乱宿主，需要没有或损坏的微生物群才能实现定殖。脊椎动物是天然V。 霍乱宿主和最近的工作已将斑马鱼建立为概括整个感染力的模型 在存在完整肠道菌群的情况下进行过程。鱼被V.霍乱迅速殖民 水，腹泻，大量霍乱葡萄菌，并将感染传递给幼稚的鱼。 因为这是自然寄主中的模型，所以它为霍乱弧菌研究提供了新的机会 哺乳动物模型可能。但是，在鱼发病机理中起作用的霍乱因子是未知的 对于O1和非O1/O1319菌株。该提案将检查两个O1使用的传染过程 和非O1/O139 V.霍乱并检验以下假设：1）V。霍乱产生特定的定殖 在人类感染中也很重要的鱼类因素。这些因素在所有V.霍乱中共享 菌株。该假设将使用TN-Seq进行检验，以鉴定对鱼类定植很重要的基因。 2）V。 霍乱会产生直接引起腹泻的因子。该假设将通过淘汰已知 每个菌株中的毒素并测量腹泻。 3）V。Cholerae perturbs肠的特定成分 微生物群，为定殖建立一个利基。该假设将通过评估微生物组来检验 并在感染后。 4）六型分泌系统（T6SS）对于与肠道的竞争很重要 微生物群。该假设将通过淘汰T6S和进一步识别的T6SS效应来检验 对于这场比赛很重要。 5）V。Cholerae由鱼类独占性高感，因为它们在人类霍乱中 凳子，这可能是V.霍乱爆发的来源。该假设将通过比较 从体外种植和鱼类霍乱的V.霍乱中殖民所需的传染剂量。 6）V。霍乱 在主机逃生之前，将其基因表达程序转移以启用传播并做出贡献 高感染性。该假设将使用RNA-Seq进行测试以确定基因表达的全局变化 在体外成长，积极殖民和独家V.霍乱之间。完成建议的工作，使用 斑马鱼作为天然V.霍乱宿主模型，将大大促进我们对 V. Cholerae的环境生活方式在天然水库中，V。Cholerae成为一个 病原体，应揭示用于治疗，环境修复和疾病的新目标 预防。该项目的长期目标是使用斑马鱼模型更好地了解V.霍乱 人类的发病机理，并确定对抗V.霍乱疾病和传播的新策略。 。