Evolutionary multispecies transcriptomics to reveal genes conferring pathogenicity within Leptospira spp

项目总结 钩端螺旋体病是一种新出现的传染病，是导致发病率和死亡率的主要人畜共患病原因。 在世界范围内，自给自足的农民和城市贫民窟人口承受着最大的负担。钩端螺旋体病导致生命- 具有威胁性的疾病，已成为世界范围内肺出血综合征(LPHS)的主要原因 和急性肾损伤。到目前为止，在资源贫乏地区尚无有效预防和控制钩端螺旋体病的方法。 设置。在美国和其他工业化国家，钩端螺旋体病是市中心疾病的主要原因 从事游泳和水上运动的人群、军事人员和个人。钩端螺旋体病是由 环境传播的螺旋体属于17个致病菌中的300多个血清型 钩端螺旋体属内的种，该属还包括26个非致病种和21个中间体 物种，后者具有不明的致病因素作用。钩端螺旋体感染的特征 它是在生物体穿过粘膜后迅速的血源性传播，传播 到宿主体内的多个器官。尽管与钩端螺旋体病相关的疾病负担相当大，但 钩端螺旋体致病的生物学和遗传学机制尚不清楚。这 知识的严重差距阻碍了更好的诊断和控制工具的开发。在这个探索性的 建议，我们假设基因表达的转变，以及基因的发散和趋同进化 功能，导致钩端螺旋体在寄主和兼性之外生存和繁衍的能力不同 致病性。为了鉴定致病基因，我们将使用比较系统生物学 方法，其中我们使用体内感染的体外模型来描述跨物种的转录 基因表达的代用品。这些体外模型模拟了细菌的流行病学生命周期和 建立疾病所必需的生物过程。通过访问我们基于HIMAR1的广泛库 突变株，我们将为其中一些目标鉴定基因中断的菌株。通过已知的功能 使用体外黏附和易位以及存活能力的良好表征的表型分析 并在水和土壤等环境基质中茁壮成长，我们将确定和表征这些环境基质的作用 致病性和传播性基因。获取致病相关基因身份的知识 而传播是理解钩端螺旋体致病机制的主要分子基础 这将通过开发改进的诊断方法直接促进公共卫生措施的进展 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.