Investigating Membrane Alterations as a Mechanism of Acid Tolerance in Cariogenic Bacteria

研究膜改变作为致龋细菌耐酸机制

• 批准号: 10174917
• 负责人: Jonathon Baker
• 金额: $ 13.09万
• 依托单位: J. CRAIG VENTER INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10174917
• 关键词: ATP phosphohydrolase; Acids; Address; Attention; Award; Bacteria; Basic Science; Biological Assay; Caries prevention; Cell membrane; Cerulenin; Chronic; Communicable Diseases; Communities; Complex; Data; Data Set; Dental Enamel; Dental caries; Dentistry; Diffusion; Disease; Ensure; Environment; Enzymes; Exhibits; Fatty Acids; Flow Cytometry; Fluorescence Microscopy; Fluorides; Funding; Gene Deletion; Genome; Goals; Health; Homologous Gene; In Vitro; Institutes; Investigation; Isomerase; Lactobacillus casei; Lipids; Liquid Chromatography; Mass Fragmentography; Mass Spectrum Analysis; Mediating; Membrane; Membrane Fluidity; Membrane Lipids; Membrane Proteins; Mentors; Metabolism; Metagenomics; Microbial Biofilms; Microbiology; Modeling; Modification; Molecular; Monitor; Oral; Oral cavity; Organism; Pathogenesis; Phase; Prevalence; Prevention strategy; Process; Production; Property; Research; Research Training; Scientist; Streptococcus mutans; Therapeutic; Training; Universities; Unsaturated Fatty Acids; Virulence; acid stress; anticaries; bacterial community; bioinformatics tool; biological adaptation to stress; career development; cariogenic bacteria; combat; community setting; demineralization; environmental stressor; fatty acid biosynthesis; fluidity; improved; inhibitor/antagonist; interest; lectures; lipidomics; medical schools; metabolomics; metatranscriptomics; microbial; microbial community; mutant; novel; novel therapeutic intervention; novel therapeutics; oral bacteria; oral biofilm; oral microbial community; oral microbiome; pathogen; prevent; programs; response; skills; tandem mass spectrometry; tooth surface

Project Summary/Abstract Dental caries is the most common chronic infectious disease globally and is caused by the formation of acid- producing bacterial biofilms on the tooth surface, which demineralize and destroy the protective underlying enamel barrier. Although the efficacy of fluoride treatments (the contemporary standard in caries prevention) is well-documented, the current prevalence of the disease clearly illustrates that fluoride alone is insufficient to prevent caries in many situations. Therefore, increased understanding of disease pathogenesis and exploration of novel preventative strategies are objectives worthy of attention. Regardless of the microbial taxa involved, bacterial acid-tolerance is an indispensable factor in caries pathogenesis. The known caries pathogen Streptococcus mutans increases the proportion of unsaturated fatty acids (UFAs) in its plasma membrane in response to environmental acidification—an adaptation required for acid-tolerance and virulence. Preliminary data indicates that several other Gram-positive oral taxa, including the caries-associated species, Lactobacillus casei, modify their membranes in a similar manner in response to environmental acidification. This proposal addresses a number of currently unanswered questions raised by these observations. Aims 1 and 2 of the proposed research will determine the scope of this response to acid stress across the oral microbiome, in single taxa or in a community setting. Aim 3 of this proposal will elucidate how these UFAs are protective against acid- mediated damage. These aims will be accomplished using bioinformatics tools, basic molecular microbiology, an ecologically-relevant and complex in vitro oral biofilm model, and mass spectrometry/lipidomics. Successful completion of the proposed research will answer pertinent questions regarding caries pathogenesis in a multi- species setting and is likely to open the door to investigation of novel anti-caries therapeutics which, while targeting acidophiles, function regardless of the presence and abundance of S. mutans. The candidate, Dr. Jonathon Baker, has a longstanding interest in the microbiology of dental caries. Upon completion of the K99 (mentored) phase of this award, his goal is to become an independent PI at a leading research university, where he plans to continue research on the modifications that bacteria make to their membranes to combat environmental stresses, while leveraging acquired data to develop novel therapeutics. A funded K99/R00 proposal will allow Dr. Baker to develop skills necessary to both complete the proposed research (training in mass spectrometry/lipidomics) and subsequently become an independent research scientist (training in didactic lecturing, mentoring, and grantsmanship). Dr. Baker’s mentors and environment: Drs. Karen Nelson (J. Craig Venter Institute), Anna Edlund (J. Craig Venter Institute/UC San Diego), Pieter Dorrestein (UC San Diego), Victor Nizet (UC San Diego) and Robert Quivey, Jr. (University of Rochester School of Medicine and Dentistry) have been carefully selected to provide high-quality, diverse scientific and collegial support, as well as state-of-the-art facilities, to ensure successful completion of this research program and the proposed career development goals.

项目总结/摘要 龋齿是全球最常见的慢性感染性疾病，是由酸性物质的形成引起的， 在牙齿表面产生细菌生物膜，使牙齿表面的保护层脱矿并被破坏 釉质屏障虽然氟化物治疗（当代龋齿预防标准）的功效 据文献记载，目前这种疾病的流行清楚地表明，单独使用氟化物不足以 在许多情况下预防龋齿。因此，增加了对疾病发病机理的认识和探索 新的预防策略是值得关注的目标。不管涉及的微生物类群， 细菌的耐酸性是龋病发病中不可缺少的因素。已知的龋齿病原体 变形链球菌增加其质膜中不饱和脂肪酸（UFA）的比例， 对环境酸化的反应--一种对耐酸和毒力的适应。初步 数据表明，其他几种革兰氏阳性口腔分类群，包括龋齿相关物种，乳杆菌， 干酪素，以类似的方式改变它们的膜以响应环境酸化。这项建议 解决了这些意见提出的一些目前尚未回答的问题。目标1和2 拟议的研究将确定这种对整个口腔微生物组的酸应激反应的范围， 分类群或社区环境中。本提案的目标3将阐明这些不饱和脂肪酸是如何防止酸- 介导的损害。这些目标将使用生物信息学工具，基础分子微生物学， 一个生态相关的和复杂的体外口腔生物膜模型，和质谱/脂质组学。成功 完成拟议的研究将回答有关龋齿发病机制的相关问题， 物种设置，并可能打开大门，调查新的抗龋治疗，而 靶向嗜酸菌，无论S的存在和丰度如何都起作用。变异人候选人，博士。 乔纳森·贝克对龋齿的微生物学有着长期的兴趣。K99完成后 他的目标是成为一所领先的研究型大学的独立PI， 他计划继续研究细菌对细胞膜的改造， 环境压力，同时利用获得的数据开发新的治疗方法。K99/R00 建议将允许贝克博士发展必要的技能，既完成拟议的研究（培训， 质谱/脂质组学），并随后成为一名独立的研究科学家（教学培训 演讲、指导和培训）。贝克博士的导师和环境：卡伦纳尔逊博士（J.克雷格 文特尔研究所）、安娜埃德伦德（J.克雷格文特尔研究所/加州大学圣地亚哥分校）、彼得多雷斯坦（加州大学圣地亚哥分校）、维克托 Nizet（UC San Diego）和Robert Quivey，Jr.（罗切斯特大学医学和牙科学院） 经过精心挑选，提供高质量，多样化的科学和学院支持，以及最先进的 设施，以确保顺利完成这项研究计划和拟议的职业发展目标。