Bacteriophage-host dynamics as a factor in the etiology of bacterial vaginosis

项目摘要 调节健康和生殖健康中阴道微生物群的物种组成和功能的机制 对这些疾病的认识不足，构成了一个基本的知识空白。阴道微生物群失调 导致与细菌性阴道病（BV）相关的症状; 妇女，导致数以百万计的医疗保健访问，每年增加风险，以获得性 传播感染和不良妊娠结局。不幸的是，治疗BV的干预措施 通常无效，复发是常见的。经过几十年的寻找和没有确定一个特定的 细菌分类群作为BV的致病因素，研究人员已经达成共识，BV本质上是一种 阴道细菌群落的组成和结构发生变化的一种生态疾病 疾病症状。然而，潜在的生物学触发因素， 在通向BV状态的路径上，是未知的。因此，拟议研究的中心假设是， 噬菌体感染是一种潜在的生物致病因素， 改变阴道细菌群落的组成，这些变化最终导致BV。 对自然环境的大量研究，以及在更有限的程度上对微生物的研究， 人体的环境，告诉我们，游离DNA病毒的社区包含一个多样化的集合， 异常丰富的病毒种群这些病毒群落主要由 噬菌体，即，细菌病毒作为高效和专门的细菌捕食者， 潜在的快速杀灭细菌种群，从而改变了共同发生的细菌的整体组成。 细菌群落据我们所知，还没有研究利用不依赖于培养的工具来直接 检查阴道内的噬菌体-宿主动力学。我们将通过两个具体的实验来验证这个假设。 目的：1）表征CRISPR/Cas系统活性的波动和CRISPR间隔区的多样性 在疾病发作之前、疾病发作当天和BV事件期间的元素;以及2）确定 游离阴道噬菌体群落的丰度和组成与BV的发作有关。到 为了实现这些目标，我们将利用一套独特的样本和元数据，这些样本和元数据是通过以下方式每天自行收集的： 135个女人10周在此期间，20名妇女出现了需要医疗的症状性BV 治疗这为我们提供了一个独特的机会来研究阴道噬菌体的生态相互作用， 使用最先进的基因组技术对BV事件中的细菌群落进行分析。的理由 一项拟议的研究是，探索和理解导致BV的生物学机制， 潜在的转化为有效的手段，以确保阴道内稳态。拟议的长期目标 研究有助于更好地了解BV的原因，在工作中的稳态机制， 人类阴道，并制定战略，以尽量减少生态失调和与BV相关的风险。 !

PROJECT SUMMARY The mechanisms that regulate the species composition and functions of vaginal microbiota in health and disease are not well understood and constitute a fundamental knowledge gap. Dysbiosis of vaginal microbiota leads to the symptoms associated with bacterial vaginosis (BV); a disease common in reproductive-age women that results in millions of health care visit annually and increases risks to the acquisition of sexually transmitted infections and adverse pregnancy outcomes. Unfortunately, interventions for the treatment of BV are often not effective and recurrence is common. After decades of looking and not identifying one particular bacterial taxa as the causative factor of BV, researchers have come to the consensus that BV is essentially an ecological disease in which shifts in the composition and structure of vaginal bacterial communities are linked with disease symptoms. However, the underlying biological trigger, which sets vaginal bacterial communities on the path to a BV state, is unknown. Thus, the central hypothesis of the proposed research is that bacteriophage infection is a contributing underlying biological causative factor capable of rapidly altering the composition of vaginal bacterial communities, changes that ultimately lead to BV. Numerous investigations of natural environments, and to a more limited extent investigations of the microbial environments of the human body, tell us that communities of free DNA viruses contain a diverse collection of extraordinarily abundant viral populations. These viral communities are composed predominantly of bacteriophages, i.e., bacterial viruses. As efficient and specialized bacterial predators, phages have the potential to rapidly decimate bacterial populations and thus alter the overall composition of co-occurring bacterial communities. To our knowledge no investigations have utilized cultivation-independent tools for direct examination of phage-host dynamics within the vagina. We will test this hypothesis by pursuing two specific aims: 1) Characterize fluctuations in the activity of CRISPR/Cas systems and the diversity of CRISPR spacer elements prior to, the day of disease onset, and during BV events; and 2) determine whether changes in the abundance and composition of free vaginal bacteriophage communities are linked to the onset of BV. To achieve these aims we will leverage a unique set of samples and metadata that were self-collected daily by 135 women for 10 weeks. During this period, 20 women experienced symptomatic BV that required medical treatment. This affords us a unique opportunity to examine the ecological interactions of vaginal phage and bacterial communities across BV events using state-of-the-art genomic technologies. The rationale for the proposed research is that exploring and understanding the biological mechanisms leading to BV has the potential to translate to effective means to insure vaginal homeostasis. The long-term goal of the proposed research is to contribute to a better understanding of the causes of BV, the homeostatic mechanisms at work in the human vagina, and to devise strategies to minimize dysbiosis and the risks associated with BV. !