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，它们产生的蛋白质可以在其中生存。生物膜污染和腐蚀管道，并在一定程度上导致动物和人类的慢性感染。这种生物膜可以“隐藏”细菌，使其免受许多抗生素和杀菌剂的侵害，同时也能将它们屏蔽在免疫系统之外。这个项目是为了确定剪切力学在产生由一种影响人类的重要病原体产生的生物膜中的作用。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，从而使社会受益。今天，防止生物被膜的方法集中在开发抵抗细菌附着或杀灭细菌的表面，但成效有限。成熟的生物膜通常抵抗治疗，除非通过机械去除，生物膜的机械破裂也会增加对传统抗生素的脆弱性。关于不同的基质材料如何控制生物膜的机制，人们几乎一无所知。这项研究将改进生物膜的预防和修复，并有利于公共卫生和基础设施，在水处理厂的管道和石油运输管道中，生物膜是一个问题。将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。第二个教育目标将导致更好的战略，为传统群体和代表不足的群体改善长期本科STEM管道。铜绿假单胞菌是一种模式生物，具有良好的遗传学和分子生物学特征，也容易形成具有重要工业和医疗影响的生物膜。生物膜力学将用流变学进行测量。受控压力将应用于单个细菌和生物膜内的细菌，并将测量由此产生的信号、表型变化和生物膜的发展。基因操作将被用来阐明特定的基因产品如何对特定的机械性能以及对机械传感、信号和生物膜的启动做出贡献。研究目的是：(1)确定剪切力学在触发启动生物膜发展的信号方面的作用--这将揭示阻碍机械传感从而防止生物膜启动的表面的设计原理；(2)确定特定生物膜组分在促进成熟生物膜的机械弹性方面的作用--这将导致可根据特定基质组成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硬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将导致生物膜预防的新范式，其目标是高度保守的信号机制，对于这些机制来说，进化逃逸将是困难的或不可能的。(2)研究目标2将为理解生物膜作为复合材料的机理提供一个新的框架。(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".