Molecular mechanisms of adaptive diversity in Burkholderia biofilms

伯克霍尔德杆菌生物膜适应性多样性的分子机制

基本信息

批准号：
8818035
负责人：
Vaughn Cooper
金额：
$ 4.74万
依托单位：
UNIVERSITY OF NEW HAMPSHIRE
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-01-01 至 2015-07-23
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8818035
关键词：
Adhesions Adverse effects Affect Archives Bacteria Binding Biochemistry Biology Burkholderia Chronic Communities Complex Confocal Microscopy Cystic Fibrosis Development Environment Evolution Foundations Generations Genetic Goals Growth Guanosine Monophosphate Hereditary Disease In Vitro Infection Learning Life Life Style Mass Spectrum Analysis Metabolism Methods Microbial Biofilms Modeling Molecular Molecular Genetics Mutate Mutation Persons Phenotype Physiological Physiology Population Population Genetics Predisposition Process Production Productivity Proteins Pseudomonas aeruginosa Regulation Resistance Second Messenger Systems Signal Transduction Staging Structure Surface System Tertiary Protein Structure Testing Time Treatment Cost Variant antimicrobial bacterial resistance base burden of illness diguanylate cyclase fitness in vitro Model in vivo mortality multidisciplinary mutant novel pathogen phosphoric diester hydrolase public health relevance reconstruction research study screening second messenger structural biology trait transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): Biofilms are associated with hundreds of thousands of infections each year and greatly increase treatment costs and mortality. These adverse effects are caused not only by increased resistance of bacteria living in the biofilm matrix but likely also by adaptive evolution of mutants into different, recalcitrant forms. To study this evolutionary process in biofilms we devised a method enabling long-term selection of populations of the opportunistic pathogen Burkholderia cenocepacia that undergo a cycle of attachment, biofilm assembly, and dispersal. Selection repeatedly favored mutations in loci commonly mutated during chronic infections, suggesting that biofilm adaptation recapitulates aspects of evolution during infections. This proposal focuses on two genetic loci that coordinate the sensing of a secreted signal (BDSF) with internal regulation of a switch governing biofilm production (cyclic-di-GMP). Mutations in different protein domains led to different ecological strategies and together different mutants produced a more robust biofilm. The overarching goal of this project is to precisely define the selective advantages of mutants with different strategie of signaling, adhesion, and dispersal in diverse biofilm environments. To tackle this complex problem we have assembled a multidisciplinary team with expertise in molecular genetics and evolutionary biology, biochemistry and mass spectrometry, and biophysical structure-function analysis. Our objectives are to 1) quantify how mutants that vary in sensing BDSF and producing cyclic-di-GMP are adaptive in biofilm communities, 2) determine how BDSF mechanistically controls the activity of the primary locus under selection, and the effects of adaptive mutations on this process, and 3) to develop an ecological model of how these processes operate in mixed-mutant and mixed-species communities. We expect to learn how this system may be manipulated to induce dispersal from biofilms and increase their susceptibility, which could be broadly relevant for developing novel antimicrobials.

描述（由申请人提供）：生物膜每年与成千上万的感染有关，并大大提高治疗成本和死亡率。这些不良反应不仅是由于生物膜基质中生活的细菌的抗性增加而引起的，而且很可能是由于突变体向不同的顽固形式的自适应进化而引起的。为了研究生物膜中的这一进化过程，我们设计了一种方法，可以长期选择机会性病原体Burkholderia cenocepacia，该人经历了附着，生物膜组装和分散的循环。选择反复偏爱在慢性感染过程中通常突变的基因座突变，这表明生物膜适应性概括了感染过程中进化的各个方面。该提案的重点是两个遗传基因座，它们协调了分泌信号（BDSF）的传感与内部调节生物膜生产的开关（Cyclic-Di-GMP）。不同蛋白质结构域中的突变导致了不同的生态策略，并且不同的突变体产生了更强大的生物膜。该项目的总体目标是精确定义具有不同信号，粘附策略和分散在不同生物膜环境中的突变体的选择性优势。为了解决这个复杂的问题，我们组装了一个具有分子遗传学和进化生物学，生物化学和质谱和生物物理结构功能分析的多学科团队。我们的目标是1）量化在传感BDSF和产生环状-DI-GMP方面的突变体在生物膜群落中是适应性的，2）确定BDSF如何机械地控制原始基因座的活性，以及适应性突变的作用以及此过程的影响，以及这些过程的生态学模型，这些方法是混合使用混合物的生态模型。我们希望如何操纵该系统以诱导生物膜分散并增加其易感性，这可能与开发新型抗菌剂有关。