Pneumococcal transition from nasopharyngeal biofilm carriage to otitis media

肺炎球菌从鼻咽生物膜携带转变为中耳炎

• 批准号: 8719687
• 负责人: Anthony A Campagnari
• 金额: $ 34.39万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8719687
• 关键词: Animal Model; Antimicrobial Resistance; Bacteria; Cessation of life; Child; Coculture Techniques; Cognitive; Complex; Data; Development; Disease; Drug Targeting; Elderly; Environment; Epidemiology; Epithelial Cells; Exposure to; Fever; Gene Expression Profile; Genes; Glucose; Goals; Host Defense; Human; Immunocompromised Host; Impairment; In Vitro; Individual; Infection; Inflammation; Influenza A virus; Integration Host Factors; Language; Measurement; Mediating; Methodology; Microbial Biofilms; Modeling; Mus; Nasopharynx; National Institute on Deafness and Other Communication Disorders; Norepinephrine; Nutrient; Otitis Media; Outcome Measure; Pathogenesis; Phenotype; Physiological; Physiology; Pneumococcal Infections; Pneumonia; Population; Process; Production; RNA Sequence Analysis; Respiratory Syncytial Virus Infections; Respiratory syncytial virus; Role; Sepsis; Signal Transduction; Simulate; Site; Sterility; Streptococcus pneumoniae; Study models; System; Techniques; Temperature; Time; Vaccines; Virulence; Virulence Factors; Virulent; Virus; Virus Diseases; antimicrobial drug; assault; base; cell injury; cold temperature; cytokine; hearing impairment; improved; in vitro Model; in vivo; influenzavirus; middle ear; novel; pathogen; public health relevance; research study; response; transcriptome sequencing

Project Summary / Abstract Streptococcus pneumoniae (the pneumococcus) is an effective colonizer of the human nasopharynx (NP) that on occasion causes disease. However, due to widespread colonization, disease occurs often enough that S. pneumoniae is a leading cause of numerous infections including otitis media (OM) in children, with associated complications, such as hearing loss and impairment of language and cognitive development. Although pneumococcal pathogenesis has been studied for a long time, our understanding of the complex interactions between the human host and bacteria, especially as they relate to colonization and the transition to OM is incomplete. Epidemiologically, transition from colonization to OM is associated with concomitant virus infection or other assaults on the host defense system, but the specific mechanisms involved are not very clear. We recently made the novel observation that pneumococcal NP carriage in vivo is associated with biofilm formation and have shown that recapitulation of this phenotype in vitro requires aspects of the NP environment, including lower temperature, interaction with epithelial cells and limited nutrient availability. Moreover, we have discovered that perturbation of this environment specifically releases bacteria from the biofilm that readily disseminate to the middle ear (ME), causing more severe disease than either biofilm bacteria or bacteria grown in broth and have a unique gene expression profile, that has allowed us to identify several molecules required for bacterial release, dissemination, and induction of OM. The goals of these studies are to mechanistically explore the signals involved in pneumococcal release from NP biofilms (both pneumococcal biofilms and poly-microbial biofilms with common NP colonizing species), dissemination to, and survival in the ME using our novel epithelial cell-based biofilm models and animal models of colonization and infection, and we hypothesize that perturbing the NP environment with dispersants such as increased temperature (fever), nutrients and ATP (associated with cell damage) and virus infection (common disease trigger), that is highly associated with pneumococcal OM will induce release of biofilm bacteria with altered phenotypes associated with increased ability to cause infection of the ME. In the studies delineated herein, we will explore release of bacteria from biofilms in vitro and in vivo after exposure to physiological changes of the normal biofilm/NP environment (Aim 1) or to influenza A virus and respiratory syncytial virus infection (Aim 2). We will then study the ability of bacteria released in vitro or in vivo to induce OM. Finally, we will expand our transcriptome analyses of the bacterial populations using RNA-seq and identify and characterize molecules involved in bacterial biofilm release, dissemination to, and induction of OM (Aim 3). The studies will provide mechanistic information regarding the release of virulent bacteria from biofilms growing in vitro and in vivo and provide specific information of the environmental and bacterial factors responsible for virulence induction in vivo that can be used to inhibit the transition to otitis media.

项目总结/摘要 肺炎链球菌（肺炎球菌）是人鼻咽部（NP）的有效定植者， 有时会导致疾病。然而，由于广泛的殖民化，疾病经常发生，足以使S。 肺炎是包括儿童中耳炎（OM）在内的多种感染的主要原因， 并发症，如听力损失和语言和认知发育障碍。虽然 肺炎球菌的发病机制已经研究了很长一段时间，我们的理解复杂的相互作用， 人类宿主和细菌之间的关系，特别是因为它们与定植和向OM的过渡有关， 不完整流行病学上，从定植到OM的转变与伴随的病毒感染有关 或其他对宿主防御系统的攻击，但涉及的具体机制还不是很清楚。 我们最近进行了新的观察，即肺炎球菌NP在体内的携带与生物膜有关 形成，并已表明，重演这种表型在体外需要方面的NP 环境，包括较低的温度，与上皮细胞的相互作用和有限的营养供应。 此外，我们还发现，这种环境的扰动会特别地将细菌从环境中释放出来。 生物膜容易扩散到中耳（ME），导致比生物膜更严重疾病 细菌或生长在肉汤中的细菌，具有独特的基因表达谱，这使我们能够识别 细菌释放、传播和诱导OM所需的几种分子。 这些研究的目的是从机制上探索肺炎球菌释放的信号 来自NP生物膜（肺炎球菌生物膜和具有常见NP定殖的多微生物生物膜 种），传播，并在ME中存活，使用我们的新的基于上皮细胞的生物膜模型， 定植和感染的动物模型，我们假设，干扰NP环境与 分散剂，如温度升高（发烧），营养素和ATP（与细胞损伤有关）和病毒 与肺炎球菌OM高度相关的感染（常见疾病触发因素）将诱导 具有改变的表型的生物膜细菌，其与引起ME感染的能力增加相关。 在本文描述的研究中，我们将探索在体外和体内施用后细菌从生物膜中的释放。 暴露于正常生物膜/NP环境的生理变化（目的1）或暴露于甲型流感病毒，以及 呼吸道合胞病毒感染（Aim 2）。然后我们将研究细菌在体外或体内释放的能力 以诱导OM。最后，我们将扩大我们的转录组分析的细菌种群使用RNA-seq 并鉴定和表征参与细菌生物膜释放、传播和诱导的分子， OM（目标3）。这些研究将提供关于从细菌中释放有毒细菌的机制信息。 在体外和体内生长的生物膜，并提供环境和细菌因素的具体信息 负责体内毒力诱导，可用于抑制向中耳炎的转变。