Role of ScfAB in the Pathophysiology of the Group A Streptococcus

ScfAB 在 A 族链球菌病理生理学中的作用

• 批准号: 9403487
• 负责人: Yoann Stephane Le Breton
• 金额: $ 22.8万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-20 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9403487
• 关键词: Acids; Acute; Address; Affect; Attenuated; Bacteria; Bacterial Infections; Blood; Cell physiology; Cessation of life; Chromosome Mapping; Complex; DNA sequencing; Data; Data Set; Development; Disease; Disease Progression; Environment; Epithelium; Functional disorder; Genes; Genetic; Genetic Screening; Genetic Transcription; Genome; Glucose; Goals; Growth; Health; Hour; Human; Immune Evasion; Impetigo; In Vitro; Infection; Infectious Skin Diseases; Invaded; Learning; Lesion; Life; Literature; Location; Membrane; Membrane Proteins; Microbial Biofilms; Modeling; Mus; Names; Necrotizing fasciitis; Nutrient; Operon; Oropharyngeal; Orthologous Gene; Pathogenesis; Pathogenicity; Pathway interactions; Peptides; Pharyngeal structure; Physiology; Play; Proteins; Publishing; Regulation; Reporting; Research Personnel; Resolution; Role; Site; Skin; Skin Tissue; Soft Tissue Disorder; Soft Tissue Infections; Sterility; Streptococcal Infections; Streptococcus mutans; Streptococcus pyogenes; Stress; Systemic infection; Tissue Model; Toxic Shock Syndrome; Transmembrane Transport; Ulcer; Virulence; Work; acid stress; base; biological adaptation to stress; clinically relevant; expectation; experience; fitness; genetic approach; genome annotation; genome-wide; improved; in vivo; mouse model; mutant; next generation; novel; novel therapeutic intervention; novel therapeutics; pathogen; permease; soft tissue; subcutaneous; tool; transcriptome sequencing; treatment group

Bacterial pathogens must adapt to changing environments in vivo in order to persist during infection within their host. Identifying genes that are "functionally required" for survival and fitness of the pathogen within the host helps to better understand pathogenesis, inform genome annotations, and guide the development of new therapeutic approaches. Tn-seq is a powerful genetic approach that allows researchers to identify en masse genes that are important for fitness in vivo using relevant models of infection. Streptococcus pyogenes (Group A Streptococcus, GAS) is a strict human pathogen and is listed among the top 10 causes of acutely life threatening bacterial infections worldwide, causing a wide array of diseases from self-limiting superficial infections of the skin & throat to severe invasive diseases of soft tissues & sterile sites. Our group has established the tools and experience to perform genome-wide genetic screens in GAS using the clinically relevant M1T1 strain 5448, and we have now completed the first in vivo Tn-seq of GAS infection in a murine model of localized GAS soft tissue infection to identify genes necessary for fitness during ulcerative lesion formation. Amongst our dataset, we identified two unannotated genes (called here subcutaneous fitness genes scfA and scfB) that were extremely important for GAS fitness in the lesion at both 24 and 48 hours post infection. Both genes are uncharacterized in GAS, but are predicted to encode membrane-associated proteins and are highly conserved among Firmicutes. The only study on scfAB homologs in the literature found them to be critical for the acid stress response and biofilm formation in S. mutans; suggesting that ScfAB functioned as a membrane permease complex. Our preliminary studies found that defined GAS M1T1 5448 mutants in scfA and scfB were outcompeted by wild type in vivo and were attenuated for survival following single strain infection in the soft tissue model. We hypothesize that the scfAB genes play an integral role in enhancing adaptation of GAS during murine soft tissue infection, and potentially in other host environments, through an as yet unknown mechanism that might involve membrane transport. The primary goal in this R21 proposal is to explore the role of ScfA and ScfB in GAS physiology and pathogenesis, with the expectation that this work will advance our understanding of how they might contribute to other important G+ pathogens. Thus, we seek to establish the contribution of scfAB to the pathophysiology of GAS via two aims: 1) Establish the localization, regulation and function of scfAB in GAS cell physiology, and 2) Investigate the impact of scfAB on GAS pathogenesis and colonization.

细菌病原体必须适应体内不断变化的环境，以便在体内感染期间持续存在。 他们的主人。鉴定病原体在环境中的生存和适应性"功能上所需"的基因， 宿主有助于更好地理解发病机制，告知基因组注释，并指导新的 治疗方法。Tn-seq是一种强大的遗传学方法，可以让研究人员识别基因组。 使用相关的感染模型对体内适应性重要的基因。化脓性链球菌（组 一种链球菌，GAS）是一种严格的人类病原体，并被列为急性生命的十大原因之一 威胁着全世界的细菌感染，导致各种各样的疾病， 从皮肤和咽喉感染到软组织和无菌部位的严重侵入性疾病。我们集团 建立了工具和经验，在GAS中使用临床 相关的M1T1菌株5448，我们现在已经完成了第一个在鼠中GAS感染的体内Tn-seq。 局部GAS软组织感染模型以鉴定溃疡性病变期间适应性所必需的基因 阵在我们的数据集中，我们确定了两个未注释的基因（这里称为皮下健身基因 scfA和scfB），这对损伤后24小时和48小时的GAS适应性极其重要 感染这两个基因在GAS中都没有特征，但被预测编码膜相关蛋白 并且在厚壁菌门中高度保守。文献中关于scfAB同源物的唯一研究发现它们 是关键的酸胁迫反应和生物膜的形成在S。变异;这表明ScfAB的功能是 膜透性酶复合物。我们的初步研究发现，scfA中定义的GAS M1T1 5448突变体 和scfB在体内被野生型胜过，并且在单菌株后被减毒存活 软组织模型中的感染。我们假设scfAB基因在增强免疫应答中起着不可或缺的作用。 GAS在小鼠软组织感染期间的适应，以及可能在其他宿主环境中，通过 可能涉及膜转运的未知机制。R21提案的主要目标是 探讨ScfA和ScfB在GAS生理和发病机制中的作用，期望这项工作 将促进我们对它们如何促进其他重要G+病原体的理解。因此，我们寻求 通过两个目的确定scfAB对GAS病理生理学的贡献：1）确定定位， scfAB在GAS细胞生理学中的调节和功能，以及2）研究scfAB对GAS的影响 发病机制和定植。