Exploring Integrative Conjugative Elements in the Biology and Ecology of Oral Streptococci

探索口腔链球菌生物学和生态学中的整合接合元件

• 批准号: 10426355
• 负责人: Robert Colquhoun Shields
• 金额: $ 13.97万
• 依托单位: ARKANSAS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10426355
• 关键词: Address; Adult; Antimicrobial Resistance; Automobile Driving; Bacteria; Bacterial Genome; Biological Process; Biological Products; Biology; CRISPR interference; Cataloging; Cellular Morphology; Centers for Disease Control and Prevention (U.S.); Child; Defect; Dental caries; Development; Disease; Ecology; Elements; Essential Genes; Evolution; Excision; Gene Silencing; Genes; Genetic Materials; Genetic Transcription; Genome; Genotype; Growth; Horizontal Gene Transfer; Human; Investigation; Knowledge; Life; Metabolic; Metalloproteases; Modeling; Names; Operon; Oral health; Organism; Outcome; Pathogenesis; Phenotype; Physiological; Physiology; Positioning Attribute; Process; Quality of life; Regulation; Streptococcus Group B; Streptococcus mutans; Study models; Technology; Tooth Loss; Virulence; Work; antimicrobial drug; base; fitness; follow-up; genetic regulatory protein; insight; interest; oral bacteria; oral biofilm; oral microbiome; oral pathogen; oral streptococci; pathogen; pathogenic bacteria; tool; trait; transcriptome

Project Summary Essential genes represent the most critical components of a bacterial genome and are required for survival. In recent years, we developed technologies that allowed us to identify and study essential genes in the dental caries pathogen Streptococcus mutans. Through these studies we have identified several genes that have unknown functions and yet, are clearly indispensable for the normal physiology of S. mutans. One of these genes, that we are provisionally naming erfR (essential regulatory factor), is annotated as a transcriptional regulator. Silencing of this gene causes severe growth and cell morphology defects, suggesting that we have identified a new and unique regulatory component of S. mutans biology. Notably, this regulatory protein is also present in the genome of other pathogens, including Group A and Group B streptococci. Since its discovery we have made advances that show that ErfR regulates the expression of a putative integrative conjugative element (ICE) known as TnSmu1. These elements participate in the horizontal transfer of genetic material, and can carry desirable traits such as antimicrobial resistance, and virulence-associated genes. ICEs could be an important mechanism driving genotypic and phenotypic diversity of this pathogen. However, there is little to no in-depth characterization of these elements in Sm. To address this knowledge gap we will exploit TnSmu1 and its regulation by ErfR as a model ICE and have developed three Specific Aims: 1) Functional analysis of TnSmu1 essentiality and potential for horizontal transfer; 2) Identify genes and metabolic activities controlled by TnSmu1 induction by transcriptome analysis; 3) Examine the impact of ICEs on Sm host fitness and evolution. Combined results and conclusions from this proposal will lead to a greater understanding of the mechanisms of erfR essentiality, TnSmu1 function and physiological effects on Sm, and the broader distribution of these elements among Sm strains. The outcomes are expected to position erfR/TnSmu1 as an important model for studying horizontal gene transfer by conjugation in oral bacteria. This will fill a void in our understanding of these elements in Sm pathogenesis and their impacts on oral biofilm ecology. The proposal will also contribute to our long-term aspirations in cataloging essential processes in Sm.

项目摘要 必需基因是细菌基因组中最关键的成分，并且是生存所必需的。在 近年来，我们开发了使我们能够识别和研究牙齿中的基本基因的技术 Caries病原体链球菌突变。通过这些研究，我们确定了几个具有 未知的功能对于链球菌的正常生理显然是必不可少的。其中之一 我们正在临时命名ERFR（基本调节因子）的基因被注释为转录 监管机构。沉默该基因会导致严重的生长和细胞形态缺陷，这表明我们有 确定了S. mutans生物学的新的独特调节成分。值得注意的是，该调节蛋白也是 存在于其他病原体的基因组中，包括A组和B组链球菌。自从发现以来 取得了进步，表明ERFR调节了推定的综合共轭的表达 元素（冰）称为tnsmu1。这些元素参与遗传物质的水平转移， 可以携带理想的性状，例如抗菌素耐药性和毒力相关基因。冰可能是 驱动该病原体的基因型和表型多样性的重要机制。但是，几乎没有 这些元素在SM中的深入表征。为了解决这个知识差距，我们将利用TNSMU1和 它由ERFR作为模型ICE的调节，并开发了三个具体目的：1）功能分析 TNSMU1的重要性和水平转移的潜力； 2）确定控制的基因和代谢活动 通过TNSMU1通过转录组分析诱导； 3）检查ICE对SM宿主健身的影响和 进化。该提案的结合结果和结论将导致对 ERFR的机制，TNSMU1功能和生理影响SM，更广泛 这些元素在SM菌株中的分布。结果有望将ERFR/TNSMU1定位为 研究水平基因通过口腔细菌结合进行的重要模型。这将填补我们的空白 了解这些元素在SM发病机理及其对口腔生物膜生态学的影响。提案 还将有助于我们在SM中分类基本过程中的长期愿望。

项目成果

Investigating CRISPR spacer targets and their impact on genomic diversification of Streptococcus mutans.

• DOI: 10.3389/fgene.2022.997341
• 发表时间: 2022
• 期刊: FRONTIERS IN GENETICS
• 影响因子: 3.7
• 作者: Walker, Alejandro R. R.;Shields, Robert C. C.
• 通讯作者: Shields, Robert C. C.

Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans.

• DOI: 10.1099/mic.0.001254
• 发表时间: 2022-10
• 期刊: MICROBIOLOGY-SGM
• 影响因子: 2.8
• 作者: King, Shawn;Quick, Allison;King, Kalee;Walker, Alejandro R.;Shields, Robert C.
• 通讯作者: Shields, Robert C.