MODE OF ACTION OF REDOX-ACTIVE COPPER SURFACES AGAINST MICROBES

氧化还原活性铜表面对抗微生物的作用方式

• 批准号: 8168310
• 负责人: GREGOR GRASS
• 金额: $ 7.08万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8168310
• 关键词: Address; Antibiotic Resistance; Area; Atomic Force Microscopy; Bacteria; Biochemistry; Cells; Chromosomes; Coin; Computer Retrieval of Information on Scientific Projects Database; Copper; DNA Damage; Drug Metabolic Detoxication; Dyes; Eukaryota; Funding; Generations; Genes; Genetic; Genetic Materials; Grant; Hospitals; Hygiene; Institution; Ions; Knowledge; Mass Spectrum Analysis; Mediating; Membrane; Metals; Microbe; Microscopy; Molecular Target; Monitor; Mutagenesis; Organism; Oxidation-Reduction; Oxidative Stress; Pilot Projects; Plasma; Plasmids; Property; Reactive Oxygen Species; Reporter; Research; Research Personnel; Resistance; Resources; Role; Source; Stress; Surface; System; Toxic effect; Trace Elements; United States National Institutes of Health; analytical method; antimicrobial; bacterial resistance; base; biological adaptation to stress; cellular targeting; fungus; improved; killings; mutant; pathogen; resistance mechanism; response; trait

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Copper (Cu) is an essential trace element for most organisms. However, when in excess Cu is also toxic, mainly caused by its redox properties and the generation of radicals. Studies using metallic Cu surfaces demonstrated excellent antimicrobial efficacy against a wide variety of bacteria. Cu surfaces killed bacteria within a few minutes. Nevertheless, the cellular targets of Cu toxicity remain obscure. Also, no studies addressed the lethal effects of Cu surfaces towards eukaryotes such s fungi. We will investigate the antimicrobial properties of metallic Cu surfaces against pro- and eukaryotes. This will be the basis for harnessing those properties in the battle against the spread of pathogens in hygiene sensitive areas like hospitals. This pilot project will explore two specific aims: Aim 1: Identify the molecular targets that govern inactivation of bacteria and fungi on metallic Cu surfaces. Use of analytical methods such as Inductively-Coupled-Plasma-Mass-Spectrometry or intracellular metal-responsive dyes will reveal if organisms exposed to Cu surfaces indeed accumulate toxic levels of Cu ions or if rather indirect effects such as redox-stress is the underlying mechanism of kill. Also, application of Atomic-Force-Microscopy and Epifluorescence Microscopy will indicate whether cells exposed to metallic Cu are inactivated because their membranes suffered lethal damage. Analysis of mutant cells lacking diverse oxidative stress response systems will clarify the role of reactive oxygen species in Cu surface mediated killing. Finally, it is currently controversially discussed if Cu toxicity targets genetic material within the cell. The response of an intracellular reporter system that monitors the integrity of the chromosome will disclose if lethal DNA damage is the underlying mechanism of action of Cu toxicity. Aim 2: Identify genetic factors responsible for resistance against metallic Cu surfaces. It is likely that bacteria that are constantly exposed to metallic Cu surfaces have evolved specific resistance mechanisms. Recently, we have isolated resistant bacteria from Cu coins. As part of the pilot project a genetic approach is planned that will elucidate the presence of plasmids conferring resistance against Cu surfaces. Genes encoding transferable resistances will be sequenced and characterized by transposon mutagenesis and mutant analysis. Further, comparison of the co-occurrence of Cu and antibiotics resistance will clarify if there is an intrinsic connection between these traits. Knowledge on the genetics and biochemistry of teh Cu detoxification systems of the coinage isolates will significantly contribute to the understanding of the mode of action of metallic Cu surfaces. On the long term, this will likely be valuable for developing advanced strategies to improve Cu surfaces that are also competent to inactivate these bacteria.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 铜（CU）是大多数生物的必不可少的痕量元素。 但是，当过量的CU也有毒时，主要是由其氧化还原特性和自由基产生引起的。 使用金属铜表面的研究表明，针对多种细菌具有出色的抗菌功效。 Cu表面在几分钟内杀死了细菌。 然而，Cu毒性的细胞靶标仍然晦涩难懂。 同样，没有研究涉及铜表面对真菌真菌的致命作用。 我们将研究金属铜表面对亲和真核生物的抗菌特性。 这将是在卫生敏感地区（如医院）与病原体蔓延的战斗中利用这些财产的基础。 该试点项目将探讨两个具体目标： 目标1：确定在金属铜表面上控制细菌和真菌失活的分子靶标。 使用分析方法（例如电感耦合 - 质量质量 - 谱法或细胞内金属响应染料）的使用将揭示出暴露于Cu表面的生物是否确实会积累有毒水平的Cu离子，或者是诸如Redox压缩效应（例如Redox压力）是杀戮的基本机制。 同样，原子能 - 微观显微镜和表落荧光显微镜的应用将表明暴露于金属铜的细胞是否被灭活，因为它们的膜遭受致命的损伤。 缺乏多种氧化应激反应系统的突变细胞的分析将阐明活性氧在Cu表面介导的杀伤中的作用。 最后，目前对CU毒性是否针对细胞内的遗传物质有争议。 监测染色体完整性的细胞内报告基因系统的响应将揭示致命的DNA损伤是CU毒性作用的基本机制。 目标2：确定负责对金属Cu表面抗性的遗传因素。 不断暴露于金属铜表面的细菌可能会发展出特定的抗性机制。 最近，我们从Cu硬币中有分离的抗性细菌。 作为试点项目的一部分，计划了一种遗传方法，该方法将阐明质粒的存在，以赋予对Cu表面的抗性。 编码可转移电阻的基因将通过转座子诱变和突变体分析进行测序和表征。 此外，比较Cu和抗生素耐药性的共发生将阐明这些特征之间是否存在固有的联系。 关于造币分离株的TEH CU解毒系统的遗传学和生物化学的知识将显着有助于理解金属Cu表面的作用方式。 从长远来看，这对于制定先进的策略来改善也有能力使这些细菌活化的铜表面可能很有价值。