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.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 中心，不一定是研究者的机构。 铜 (Cu) 是大多数生物体必需的微量元素。 然而，过量的铜也是有毒的，这主要是由于其氧化还原特性和自由基的产生造成的。 使用金属铜表面的研究表明，对多种细菌具有优异的抗菌功效。 铜表面可在几分钟内杀死细菌。 然而，铜毒性的细胞靶标仍然不清楚。 此外，还没有研究探讨铜表面对真菌等真核生物的致命影响。 我们将研究金属铜表面对原核生物和真核生物的抗菌特性。 这将成为利用这些特性对抗医院等卫生敏感区域的病原体传播的基础。 该试点项目将探讨两个具体目标： 目标 1：确定控制金属铜表面细菌和真菌失活的分子靶标。 使用感应耦合等离子体质谱或细胞内金属响应染料等分析方法将揭示暴露于铜表面的生物体是否确实积累了有毒水平的铜离子，或者氧化还原应激等间接影响是否是潜在的机制的杀戮。 此外，原子力显微镜和落射荧光显微镜的应用将表明暴露于金属铜的细胞是否因为细胞膜遭受致命损伤而失活。 对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铜表面介导的杀伤作用中的作用。 最后，目前关于铜毒性是否针对细胞内遗传物质的讨论存在争议。 监测染色体完整性的细胞内报告系统的反应将揭示致命的 DNA 损伤是否是铜毒性作用的潜在机制。 目标 2：确定导致金属铜表面耐受性的遗传因素。 持续暴露于金属铜表面的细菌很可能已经进化出特定的抵抗机制。 最近，我们从铜币中分离到了耐药细菌。 作为试点项目的一部分，计划采用遗传方法来阐明赋予铜表面抗性的质粒的存在。 编码可转移抗性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，比较铜和抗生素耐药性的共现将阐明这些性状之间是否存在内在联系。 有关造币分离物的铜解毒系统的遗传学和生物化学知识将极大地有助于理解金属铜表面的作用模式。 从长远来看，这对于开发先进的策略来改善铜表面也可能具有灭活这些细菌的作用。