| 项目编号: | 1719325
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| 项目名称: | EAGER: Antibacterial clay effects on pathogenic biofilms |
| 作者: | Lynda Williams
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| 承担单位: | Arizona State University
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| 批准年: | 2017
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| 开始日期: | 2017-04-01
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| 结束日期: | 2019-03-31
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| 资助金额: | 240784
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | antibacterial clay
; biofilm
; clay
; effect
; healthy biofilm
; metal
; clay mineral assemblage buffer
; investigator
; bactericidal effect
; common clay mineral
; testing natural clay
; clay suspension
|
| 英文摘要: | Recent research by the investigator on clays that kill human pathogens, including antibiotic resistant strains like methicillin resistant S. aureus (MRSA), has documented their common characteristics. Worldwide, only 5-10 % of clays studied to date are antibacterial when hydrated and tested in vitro. Most antibacterial clays are from hydrothermally altered volcanics, where volcanogenic fluids produce minerals containing reduced metals. Ferruginous illite-smectite (I-S) is the most common clay mineral, although kaolins dominate some samples. Antibacterial clay mineral assemblages may also contain non-clay reduced Fe-minerals (e.g., pyrite) that oxidize, causing damage to cell membranes and intracellular proteins. The key is that the clay mineral assemblage buffers the hydration water to pH and Eh conditions that release metals critical to the antibacterial process, allowing interaction with the bacteria. Antibacterial clays also exchange structural ions with the bacterial membrane that weaken bacterial defenses. This research will take this new understanding of the antibacterial process, to the next level by testing their effect on biofilms. Infectious diseases in humans commonly form biofilms, which are communities of bacteria more resistant to antibiotics than the "free floating" bacterial suspensions tested. The effectiveness of antibacterial clay on biofilms is an important step in supporting the costly testing of the bactericidal effect in animal trials. If antibacterial clay is effective against biofilms, in vivo testing may lead to design of new treatments for antibiotic resistant bacteria, with potential applications in wound dressings, medical implants (joint replacements, catheters), animal feed stocks, agricultural pathogens, and production of antibacterial building materials.
The scientific goal of this research is to document the effect of an antibacterial clay previously tested against a broad spectrum of planktonic human pathogens, on biofilms most common to infectious diseases. In collaboration with infectious disease researchers at the Mayo Clinic (Rochester, MN), the investigator will develop protocols for the application of clays to biofilms and evaluate conditions that lead to, or limit, their antibacterial activity. Clinical isolates of common and antibiotic resistant bacterial strains will be tested. The investigator has demonstrated that antibacterial clays release metals (Aluminum, Iron) that act together to damage cell membranes and intracellular proteins so they will monitor the interaction of these metals with the biofilms. Standard methods for testing antibiotics must be modified for testing natural clay because the minerals, while releasing metals, are not completely dissolved and therefore will affect spectroscopic evaluations of bacterial viability. Furthermore, the investigator found that metal speciation in various growth media affect results by limiting metal reactivity with bacteria. Therefore, healthy biofilms grown on Teflon disks will be incubated with clay suspensions and cultures will be evaluated for viability by serial dilution and plate counting. If successful, this project will bridge the gap between mineralogy and medicine promoting applications of clay or its derivatives to antibiotic resistant infections. This will enhance development of medical protocols for evaluating minerals that improve human health. The ultimate benefit to society will be to establish an economical and safe natural mineral cure for antibiotic-resistant infections. Proof of the antibacterial activity and safety for applications in wound care may lead to an economic use of clays to treat wounds, or to development of new medicines that incorporate similar antibacterial properties. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/90379
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Lynda Williams. EAGER: Antibacterial clay effects on pathogenic biofilms. 2017-01-01.
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