Nonthermal Atmospheric Plasma Rapidly Disinfects Multidrug-Resistant Microbes by Inducing Cell Surface Damage
Nonthermal Atmospheric Plasma Rapidly Disinfects Multidrug-Resistant Microbes by Inducing Cell Surface Damage
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DOI：
10.1128/aac.05642-11
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发表时间：
2012-04-01
影响因子：
4.9
通讯作者：
Garner, Allen L.
中科院分区：
文献类型：
--
作者：
Kvam, Erik;Davis, Brian;Garner, Allen L.
等离子体是一种独特的物质状态，具有与电离气体相似的性质，是一种有效的生物消毒剂。然而，非热或“冷”等离子体灭活表面上微生物的机制知之甚少，部分原因是与处理和分析表面上而不是水溶液中的活细胞相关的挑战。在这里，我们采用膜吸附技术来可视化血浆对耐药微生物的代表性临床分离株的细胞效应。通过直接荧光成像，我们证明了血浆通过以时间依赖性方式破坏细胞表面，在30 s内快速灭活细胞增殖培养物，>5 log（10）杀死，导致膜完整性丧失，细胞内组分（核酸，蛋白质，ATP）泄漏，并最终在较长的暴露时间内细胞表面局部溶解。耐甲氧西林金黄色葡萄球菌（MRSA）、铜绿假单胞菌和白色念珠菌的动力学速率相似。我们没有观察到相关的证据表明，血浆诱导广泛的基因组损伤或氧化蛋白质修饰之前发生的膜损伤。与血浆是表面的概念一致，当在处理前将微生物细胞包封在水性缓冲液中时，血浆介导的灭菌显著减少。这些结果支持使用非热等离子体对环境中的多重耐药微生物进行消毒，并证实了等离子体器械正在进行的临床应用。
Plasma, a unique state of matter with properties similar to those of ionized gas, is an effective biological disinfectant. However, the mechanism through which nonthermal or "cold" plasma inactivates microbes on surfaces is poorly understood, due in part to challenges associated with processing and analyzing live cells on surfaces rather than in aqueous solution. Here, we employ membrane adsorption techniques to visualize the cellular effects of plasma on representative clinical isolates of drug-resistant microbes. Through direct fluorescent imaging, we demonstrate that plasma rapidly inactivates planktonic cultures, with >5 log(10) kill in 30 s by damaging the cell surface in a time-dependent manner, resulting in a loss of membrane integrity, leakage of intracellular components (nucleic acid, protein, ATP), and ultimately focal dissolution of the cell surface with longer exposure time. This occurred with similar kinetic rates among methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. We observed no correlative evidence that plasma induced widespread genomic damage or oxidative protein modification prior to the onset of membrane damage. Consistent with the notion that plasma is superficial, plasma-mediated sterilization was dramatically reduced when microbial cells were enveloped in aqueous buffer prior to treatment. These results support the use of nonthermal plasmas for disinfecting multidrug-resistant microbes in environmental settings and substantiate ongoing clinical applications for plasma devices.