Evolutionary multispecies transcriptomics to reveal genes conferring pathogenicity within Leptospira spp

项目摘要 钩端螺旋体病是一种新出现的传染病，是导致发病和死亡的主要人畜共患病原因 在世界范围内，自给农民和城市贫民窟人口的负担最大。钩端螺旋体病会导致生命- 肺出血综合征（LPHS）是一种严重威胁人类健康的疾病，已成为世界范围内肺出血综合征的主要病因 和急性肾损伤到目前为止，在资源贫乏的地区， 设置.在美国和其他工业化国家，钩端螺旋体病是市中心居民的主要致病原因 人口、军事人员和从事游泳和水上运动的个人。钩端螺旋体病是由 环境传播的螺旋体属于十七种致病性中的300多种血清型 钩端螺旋体属内的26个种，该属还包括26个非致病性种和21个中间种 物种，后者作为疾病病原体的作用不明确。钩端螺旋体感染的标志 是其在生物体穿透粘膜后的快速血行播散， 感染到宿主的多个器官尽管与钩端螺旋体病相关的疾病负担相当大， 与钩端螺旋体相关的发病机理的生物学和遗传学机制仍然知之甚少。这 知识上的重大差距阻碍了更好的诊断和控制工具的发展。在这个探索性的 我们假设，基因表达的变化，以及基因的趋异和趋同进化， 功能，导致钩端螺旋体在宿主和兼性宿主外生存和繁衍能力的多样性 致病性为了确定致病基因，我们将使用比较系统生物学方法， 方法，在该方法中，我们使用体内感染的体外模型对跨物种的转录进行分析， 基因表达的替代物。这些体外模型模拟了细菌的流行病学生命周期， 生物学过程对疾病的形成至关重要。通过访问我们广泛的基于himar 1的库， 突变体，我们将确定其中一些目标的基因破坏菌株。通过已知的功能 表型使用良好表征的体外粘附和易位测定，以及存活能力 并在水和土壤等环境基质中茁壮成长，我们将确定和描述这些环境基质的作用。 致病和传播的基因。了解致病基因的特性 和传播是从分子水平上了解钩端螺旋体致病机制的一个主要优先事项 这将直接促进公共卫生措施的进步，通过发展改进的诊断， 和预防方法。

PROJECT SUMMARY Leptospirosis is an emerging infectious disease and the leading zoonotic cause of morbidity and mortality worldwide, with its greatest burden on subsistence farmers and urban slum populations. Leptospirosis causes life- threatening disease and has emerged as a major cause worldwide of pulmonary hemorrhage syndrome (LPHS) and acute kidney injury. To date, there is no effective prevention and control for leptospirosis in resource-poor settings. In the US and other industrialized countries, leptospirosis is a major cause of disease among inner-city populations, military personnel, and individuals engaged in swimming and water sports. Leptospirosis is caused by environmentally transmitted spirochetes belonging to more than 300 serovars among seventeen pathogenic species within the genus Leptospira, a genus that also comprises 26 non-pathogenic species and 21 intermediate species, the latter with undefined role as disease causative agent. The hallmark of infection with Leptospira species is its rapid hematogenous dissemination after the organism penetrates through mucous membranes, disseminating to multiple organs throughout the host. Despite the sizable burden of disease associated with leptospirosis, the biological and genetic mechanisms of pathogenesis associated with Leptospira remain poorly understood. This crucial gap of knowledge has impaired the development of better diagnostic and control tools. In this exploratory proposal, we hypothesize that shifts in gene expression, together with divergent and convergent evolution of gene function, have led to diversity in ability of Leptospira to survive and thrive outside of the host and facultative pathogenicity. To identify genes responsible for pathogenicity, we will use a comparative systems biological approach, in which we profile transcription across species using in vitro models of infection that are in vivo surrogates for gene expression. Those in vitro models mimic the epidemiological life cycle of the bacteria and the biological processes essential to establish disease. Through access to our extensive library of himar1-based mutants, we will identify strains with gene disruption for some of those targets. Through known functional phenotypes using well-characterized in vitro assays of adherence and translocation, as well as ability to survive and thrive in environmental matrices such as water and soil, we will determine and characterize the role of those genes in pathogenicity and transmission. Acquiring knowledge of the identity of genes responsible for pathogenicity and transmission is a major priority for the molecular understanding of the mechanisms of leptospiral pathogenesis that will directly facilitate the advance of public health measures through the development of improved diagnostic and prevention methods.