Establishing microbial and biochemical thresholds for development and persistence

建立发育和持久性的微生物和生化阈值

• 批准号: 8769641
• 负责人: Joshua Tisdell Schiffer
• 金额: $ 23.1万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8769641
• 关键词: Accounting; Amino Acids; Antibiotic Therapy; Atopobium vaginae; Automobile Driving; Bacteria; Bacterial Vaginosis; Behavior; Behavioral; Biochemical; Biological; Biological Assay; Characteristics; Coculture Techniques; Communities; Complement; Complex; Controlled Environment; Coupled; Data; Dependence; Development; Differential Equation; Discipline; Disease; Environment; Environmental Risk Factor; Equilibrium; Estrogens; Event; Experimental Models; Gardnerella vaginalis; Global Change; Glucose; Growth; HIV Infections; Hemoglobin; High Pressure Liquid Chromatography; Hormonal; Human; In Vitro; Individual; Investigation; Iron; Kinetics; Knowledge; Laboratories; Laboratory Finding; Lactic acid; Lactobacillus; Lead; Link; Maintenance; Measures; Menstruation; Metabolic; Microbe; Microbial Biofilms; Microfluidic Microchips; Microfluidics; Modeling; Monitor; Natural History; Nutrient; Observational Study; Operative Surgical Procedures; Pathway interactions; Pelvic Inflammatory Disease; Play; Polyamines; Predisposing Factor; Premature Birth; Prevention strategy; Recurrence; Relative (related person); Reproductive Health; Research; Resolution; Risk; Sampling; Sexually Transmitted Diseases; Simulate; Structure; Swab; System; Testing; Time; Universities; Vagina; Vaginal Discharge; Washington; Woman; base; diaries; human data; improved; in vivo; insight; mathematical model; microbial; microbial community; novel; prevent; pyrosequencing; rRNA Genes; research study; tool; treatment strategy

ABSTRACT The microbial environment in the human vagina is extremely dynamic. Bacterial communities can shift dramatically from lactobacillus predominance, to a diverse, polymicrobial state, which is a fundamental characteristic of bacterial vaginosis (BV). BV is a clinically important condition associated with vaginal discharge as well as heightened risk of preterm birth, pelvic inflammatory disease, post-surgical infections, HIV and other sexually transmitted infections. Unfortunately, little is known about the factors that prompt transitions between simple and complex microbial communities and in particular, why BV commonly recurs following antibiotic treatment. The purpose of this proposal is to use complementary tools from multiple disciplines to describe the influence of environmental factors and interspecies interactions on vaginal bacterial dynamics. Our focus will be on characterizing factors underlying BV recurrence, maintenance and resolution. We hypothesize that threshold concentrations of certain species and nutrients are necessary for recurrent BV, while different conditions, in particular establishment of biofilms, are required for maintenance of this anaerobic, polymicrobial state. In Aim 1 we will define the natural history of bacterial kinetics by collecting vaginal swabs in women 3 times per day for 60 days, to measure abundance of specific bacterial species with qPCR. We will also collect daily behavioral diaries, and sample for pH and nutritive biochemicals such as hemoglobin and glucose which are known to vary with hormonal cycling. In addition, we will perform broad-range 16S rRNA gene PCR with pyrosequencing to describe global changes in microbial community profile diversity. We will therefore be able to identify the key microbial and nutrient conditions that predict abrupt transitions in vagina microbiota. In Aim 2 we will measure bacterial growth, competition, and biofilm behavior under selective metabolic conditions using a realistic microfluidic in vitro cultivation system. We will manipulate key bacterial metabolites such as amino acids, host derived nutrients such as glucose and iron, environmental conditions such as pH, and other biophysical features of the vagina such as shear forces and biofilm formation, to assess the effect of these variable on microbial growth rates, as well as microbial competition among multiple species for scare nutrients. In Aim 3 we will use findings from the laboratory experiments (Aim 2) to populate mathematical models with competing assumptions that describe bacterial community dynamics. Models will be tested for their ability to reproduce key dynamic features from human longitudinal data in Aim 1. The optimal model will generate mechanistic explanations for observations from Aims 1 and 2, and will identify conditions necessary for development, maintenance and eradication of BV. A greater understanding of the necessary conditions for abrupt microbial shifts will offer pathways for improving reproductive health.

抽象的 人类阴道内的微生物环境极其动态。细菌群落可以发生变化 戏剧性地从乳酸菌占主导地位转变为多样化的多微生物状态，这是一个基本的 细菌性阴道病（BV）的特征。 BV 是一种与阴道相关的重要临床疾病 出院以及早产、盆腔炎、术后感染、艾滋病毒的风险增加 和其他性传播感染。不幸的是，人们对促使转变的因素知之甚少 简单微生物群落和复杂微生物群落之间的关系，特别是为什么 BV 通常会在以下情况下复发 抗生素治疗。该提案的目的是使用多个学科的补充工具来 描述环境因素和种间相互作用对阴道细菌动态的影响。 我们的重点将是描述 BV 复发、维持和解决的潜在因素。我们 假设某些物种和营养素的阈值浓度对于复发性 BV 是必要的， 虽然维持这种厌氧需要不同的条件，特别是生物膜的建立， 多微生物状态。在目标 1 中，我们将通过收集阴道拭子来定义细菌动力学的自然史 女性每天 3 次，持续 60 天，通过 qPCR 测量特定细菌种类的丰度。我们将 还收集日常行为日记，并采样 pH 值和营养生化物质，如血红蛋白和 已知葡萄糖随荷尔蒙循环而变化。此外，我们还将进行广泛的 16S rRNA 基因 PCR 结合焦磷酸测序来描述微生物群落谱多样性的全球变化。我们将 因此能够识别预测阴道突变的关键微生物和营养条件 微生物群。在目标 2 中，我们将测量选择性条件下的细菌生长、竞争和生物膜行为 使用真实的微流体体外培养系统的代谢条件。我们将操纵关键细菌 氨基酸等代谢物、葡萄糖和铁等宿主衍生营养素、环境条件 例如 pH 值以及阴道的其他生物物理特征（例如剪切力和生物膜形成），以评估 这些变量对微生物生长速率以及多个物种之间的微生物竞争的影响 为了吓人的营养。在目标 3 中，我们将使用实验室实验（目标 2）的结果来填充 具有描述细菌群落动态的竞争假设的数学模型。型号将是 测试了它们从目标 1 中的人类纵向数据再现关键动态特征的能力。 模型将为目标 1 和 2 的观察结果生成机械解释，并将识别条件 对于 BV 的发展、维持和根除所必需的。对必要的内容有更深入的了解 微生物突变的条件将为改善生殖健康提供途径。