Bacterial persistence and proton-motive force

细菌持久性和质子动力

• 批准号: 10593822
• 负责人: Pushkar Prakash Lele
• 金额: $ 26.07万
• 依托单位: TEXAS ENGINEERING EXPERIMENT STATION
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-04 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10593822
• 关键词: ATP Synthesis Pathway; Agar; Ampicillin; Antibiotic Resistance; Antibiotics; Bacteria; Biological Assay; Biophysics; Cell division; Cell physiology; Cells; Clinical; Coupled; Data; Dyes; Escherichia coli; Excision; Exhibits; Exposure to; Fatigue; Flagella; Fluorescence; Foundations; Future; Goals; Growth; Healthcare; Heterogeneity; Hour; Image Analysis; Infection; Interphase Cell; Measurement; Measures; Membrane; Membrane Potentials; Microfluidic Microchips; Microfluidics; Modeling; Morphology; Mothers; Motor; Nutrient; Outcome; Pharmaceutical Preparations; Phenotype; Play; Population; Probability; Process; Proton-Motive Force; Public Health; Recurrent disease; Reporter; Resistance to infection; Rest; Role; Rotation; Sampling; Source; Stress; Swimming; Techniques; Testing; Toxin; Variant; Work; antitoxin; biophysical techniques; cell motility; chronic infection; combat; drug resistant pathogen; experimental study; fitness; innovation; multidrug tolerance; optic trap; optical traps; pH gradient; pathogen; pathogenic bacteria; persistent bacteria; quantitative imaging; rapid growth; recurrent infection; symporter; tool; uptake

ABSTRACT Bacterial persistence is a robust mechanism employed by bacteria to survive antibiotic stress, and is likely to be a major cause of chronic infections. Bacterial persisters are genetically indistinct from the rest of the population, and likely emerge due to phenotypic variations that are inherently stochastic. Although all major bacterial pathogens produce persisters, the mechanisms of persistence are poorly understood. Persisters do not exhibit any discernible morphological differences from the rest of the cell population. This adds to the challenges of studying how persisters emerge in natural bacterial populations. Among the known mechanisms involve toxin-antitoxin (TA) modules, which dissipate the proton-motive force (PMF) and promote persister formation. Persisters may also arise due to energetic deficiencies, which induce dormancy in cells. However, persister populations are quite heterogeneous in many regards and identifying the mechanisms of persistence will continue to remain challenging until the sources of heterogeneity are determined. In the proposed work, the objective is to quantify the heterogeneity in the PMF of persisters and study key factors that influence fitness in persister populations. The long-term goal is to develop a mechanistic understanding of the stochastic phenomenon governing persistence. The proposed work is innovative as it combines single-cell biophysical assays including optical trapping with fluorescence techniques and quantitative image analysis – these tools will be used to quantify the heterogeneities in the PMF that might prevail in persister populations of Escherichia coli. The innovative approaches proposed will also help test correlations between the measured heterogeneities and the occurrence of persistence under different antibiotic stresses. In particular, the central hypothesis that low energy levels can predict the probability of persister formation will be tested. Successful execution of this project will lay the foundation for future efforts to determine how bacterial energetics influence persistence mechanisms. As persisters likely play a major role in clinical recurrence of disease, they are a major burden on the public healthcare. This coupled with the emerging threat of antibiotic resistance makes the proposed work timely and critical.

抽象的 细菌持久性是细菌在抗生素应激下生存的一种强大机制，并且是 可能是慢性感染的主要原因。细菌存留者在基因上与其他细菌并无区别。 群体，并且可能由于本质上随机的表型变异而出现。虽然所有主要 细菌病原体会产生持久性，但其持久性机制尚不清楚。坚持者做 与其他细胞群没有表现出任何明显的形态差异。这增加了 研究持久性细菌如何在自然细菌种群中出现的挑战。在已知的机制中 涉及毒素-抗毒素（TA）模块，它耗散质子动力（PMF）并促进持久化 形成。持久性也可能是由于能量不足而引起的，这会导致细胞休眠。然而， 持久性种群在许多方面都具有相当的异质性，并确定持久性机制 在确定异质性的来源之前，这一问题将继续具有挑战性。在拟议的工作中， 目标是量化持久者 PMF 的异质性并研究影响持久性的关键因素 持续存在的人群。长期目标是发展对随机性的机械理解 支配持久性的现象。拟议的工作具有创新性，因为它结合了单细胞生物物理 包括使用荧光技术进行光捕获和定量图像分析的检测 – 这些工具 将用于量化埃希氏菌持久种群中可能普遍存在的 PMF 的异质性 大肠杆菌。所提出的创新方法还将有助于测试测量值之间的相关性 异质性和不同抗生素胁迫下持久性的发生。特别是中央 低能量水平可以预测持续存在的可能性的假设将得到检验。成功的 该项目的执行将为未来确定细菌能量学如何影响奠定基础 持久化机制。由于持续存在者可能在疾病的临床复发中发挥重要作用，因此它们是 公共医疗保健的重大负担。这加上抗生素耐药性的新威胁使得 提出的工作及时、关键。