Mechanics-Targeting Strategies for Biofilm Prevention and Remediation

生物膜是微生物群落，它们通过聚合物和蛋白质的基质相互结合，并在其中生存。生物膜污染和腐蚀管道，并部分导致动物和人类的慢性感染。生物膜“隐藏”了许多抗生素和杀菌剂对细菌的影响，也掩盖了它们对免疫系统的影响。本项目旨在确定剪切力学在一种影响人类的重要病原体形成生物膜中的作用。这将为预防和清除针对机械特性的生物膜的新方法奠定基础，从而造福社会。今天，防止生物膜的方法集中在开发抵抗细菌附着或杀死细菌的表面上，但收效甚微。成熟的生物膜通常会抵抗治疗，除非通过机械去除，而生物膜的机械破裂也会增加对常规抗生素的脆弱性。关于不同的基质材料如何控制生物膜的机制，我们几乎一无所知。本研究将改善生物膜的预防和修复，并有利于公共卫生和基础设施中存在生物膜问题的地方，如水处理厂管道，石油运输管道。在第一个教育目标中开发的教育模块将与高中生物、物理和数学课程的标准保持一致，提供对科学知识如何发展的经验理解，并教授跨学科的核心概念。第二个教育目标将带来更好的战略，以改善传统和代表性不足群体的长期本科STEM管道。铜绿假单胞菌是一种具有良好遗传学和分子生物学特征的模式生物，也容易形成具有重要工业和医学影响的生物膜。生物膜力学将用流变学来测量。将对单个细菌和生物膜内的细菌施加控制应激，并测量由此产生的信号，表型变化和生物膜发育。基因操作将用于阐明特定的基因产物如何促进特定的机械性能，机械传感，信号传导和生物膜起始。研究目标是：(1)确定剪切力学在触发启动生物膜形成的信号中的作用——这将揭示阻碍机械传感从而阻止生物膜形成的表面设计原则；(2)确定特定生物膜成分在促进成熟生物膜的机械弹性中的作用-这将导致可根据特定基质成分和机械性能进行调整的破坏和清除策略；(3)确定组成细菌对生物膜刚度和应变的机械感觉反应——这将表明如何降低生物膜的动态适应能力并增加其机械稳健性。(1)研究目标1将为生物膜预防提供一个新的范例，该范例针对高度保守的信号机制，这些机制在进化上很难或不可能逃脱。(2)研究目标2将为理解生物膜作为复合材料的机制提供一个新的框架。(3)研究目标3将产生关于生物膜如何作为多细胞、力敏感的“组织”的新知识。

Biofilms are communities of microbes that are bound to each other by a matrix of polymers and proteins that they produce in which to live. Biofilms foul and corrode pipes, and partially cause chronic infections in animals and humans. The biofilm "hides" the bacteria from many antibiotics and bacteriocides, and also masks them from the immune system. This project is to determine the role of shear mechanics in the creating the biofilms made by an important pathogen that affects humans. This will benefit society by laying the groundwork for new approaches to preventing and clearing biofilms that target mechanical characteristics. Today the approaches to preventing biofilms focus, with limited success, on developing surfaces that resist bacterial attachment or that kill bacteria. Mature biofilms often resist treatment, except by mechanical removal, and mechanical breakup of biofilms can also increase vulnerability to conventional antibiotics. Almost nothing is known about how different matrix materials control the mechanics of biofilms. This research will improve biofilm prevention and remediation and benefit public health and infrastructure where biofilms are a problem such as in the piping of water treatment plants, and oil transport piping. Educational modules to be developed in the first Educational goal will be aligned with standards for high school curricula in biology, physics, and math, provide an experiential understanding of how scientific knowledge is developed and teach discipline-crossing core concepts. The second educational goal will lead to better strategies for improving the long-term undergraduate STEM pipeline for both traditional and under-represented groups.Pseudomonas aeruginosa is a model organism with well-characterized genetics and molecular biology, and also readily forms biofilms with important industrial and medical impact. Biofilm mechanics will be measured using rheology. Controlled stress will be applied to single bacteria and to bacteria within biofilms, and the resulting signaling, phenotypic changes, and biofilm development will be measured. Genetic manipulation will be used to elucidate how specific gene products contribute to specific mechanical properties and to mechanosensing, signaling, and biofilm initiation. Research Aims are: (1) determine the role of shear mechanics in triggering the signal that initiates biofilm development - this will reveal design principles for surfaces that thwart mechanosensing and thereby prevent biofilm initiation; (2) determine the role of specific biofilm components in contributing to mechanical resilience of the mature biofilm - this will result in strategies for disruption and clearance that are tunable to specific matrix composition and mechanical properties; (3) determine the mechanosensory response of constituent bacteria to biofilm stiffness and strain - this will indicate how to reduce biofilms' ability to dynamically adapt and increase their mechanical robustness. (1) Research Aim 1 will result in a new paradigm for biofilm prevention that targets highly-conserved signaling mechanisms for which evolutionary escape will be difficult or impossible. (2) Research Aim 2 will result in a new framework for understanding the mechanics of biofilms as composites. (3) Research Aim 3 will result in new knowledge of how biofilms may act as multicellular, force sensitive "tissues".