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: 8798654
• 负责人: Anthony A Campagnari
• 金额: $ 33.53万
• 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/8798654
• 关键词: Animal Model; Antimicrobial Resistance; Bacteria; Cessation of life; Child; Coculture Techniques; Complex; Data; Disease; Drug Targeting; Elderly; Environment; Epidemiology; Epithelial Cells; Exposure to; Fever; Gene Expression Profile; Genes; Glucose; Goals; Health; Host Defense; Human; Immunocompromised Host; Impairment; In Vitro; Individual; Infection; Inflammation; Influenza A virus; Integration Host Factors; Language Development; 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; Site; Sterility; Streptococcus pneumoniae; Study models; System; Techniques; Temperature; Time; Vaccines; Virulence; Virulence Factors; Virulent; Virus; Virus Diseases; antimicrobial drug; assault; base; cell injury; cognitive development; cold temperature; cytokine; hearing impairment; improved; in vitro Model; in vivo; influenzavirus; middle ear; novel; pathogen; research study; response; transcriptome sequencing

DESCRIPTION (provided by applicant): 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 n 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.

描述（由申请人提供）：肺炎链球菌（肺炎球菌）是人类鼻咽（NP）的有效菌落体，有时会引起疾病。但是，由于广泛的定殖，疾病经常发生，以至于肺炎链球菌是许多感染的主要原因，包括儿童中耳炎（OM），以及相关并发症，例如听力丧失和语言和认知发展的障碍。尽管已经研究了肺炎球菌发病机理已有很长时间了，但我们对人类宿主与细菌之间的复杂相互作用的理解，尤其是在与定殖有关的时，并且向OM的过渡是不完整的。从流行病学上讲，从定殖到OM的过渡与伴随的病毒感染或对宿主防御系统的其他攻击有关，但涉及的具体机制并不清楚。最近，我们对体内的肺炎球菌NP托架与生物膜形成有关，并表明在体外对这种表型的概括需要NP环境的各个方面，包括较低的温度，与上皮细胞的相互作用和有限的养分利用率。 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诸如温度升高（发烧），营养素和ATP（与细胞损伤有关）和病毒感染（常见疾病触发）等分散剂与肺炎球菌OM高度相关，将诱导与引起ME感染能力相关的表型改变的生物膜细菌。在本文描述的研究中，我们将在暴露于正常生物膜/NP环境的生理变化后（AIM 1）或流感病毒和呼吸道合成病毒后，探索体外和体内生物膜释放的细菌（AIM 1）（AIM 2）。然后，我们将研究细菌在体外释放或n个体内诱导OM的能力。最后，我们将使用RNA-seq扩展对细菌种群的转录组分析，并识别和表征与细菌生物膜释放，传播和诱导OM相关的分子（AIM 3）。这项研究将提供有关从体外生长和体内生长的生物膜释放毒细菌的机械信息，并提供负责体内毒力诱导的环境和细菌因子的特定信息，这些信息可用于抑制向耳炎培养基的过渡。