Is gas-discharge plasma a new solution to the old problem of biofilm inactivation?
Is gas-discharge plasma a new solution to the old problem of biofilm inactivation?
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DOI：
10.1099/mic.0.021501-0
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发表时间：
2009-03-01
期刊：
影响因子：
2.8
通讯作者：
Brelles-Marino, Graciela
中科院分区：
文献类型：
--
作者：
Joaquin, Jonathan C.;Kwan, Calvin;Brelles-Marino, Graciela
传统的消毒和灭菌方法通常对生物膜无效，生物膜是普遍存在的，难以破坏的微生物群落，嵌入主要由胞外多糖组成的基质中。气体放电等离子体的使用是一种替代方法，因为等离子体含有带电粒子、化学活性物质和紫外线辐射的混合物，其对自由生活的浮游微生物的去污潜力已得到充分证实。在这项研究中，使用紫色色杆菌（Chromobacterium violaceum）产生生物膜，紫色色杆菌是一种存在于土壤和水中的革兰氏阴性细菌，并在这项研究中用作模式生物。生物膜经受大气压等离子体射流不同的暴露时间。我们的结果表明，99.6%的可培养细胞在处理5分钟后被灭活。存活曲线显示双斜率动力学，c.f.u.在初始时快速下降。ml（-1），然后下降得慢得多，D值比浮游生物的失活时间长，表明生物膜的失活机制更复杂。DNA和ATP测定以及原子力显微镜和荧光显微镜显示，不可培养的细胞在短的血浆暴露时间后仍然存活。这些结果表明，血浆的生物膜灭活的潜力，并表明，细胞经历了一系列的生理和形态学的变化，然后灭活。
Conventional disinfection and sterilization methods are often ineffective with biofilms, which are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides. The use of gas-discharge plasmas represents an alternative method, since plasmas contain a mixture of charged particles, chemically reactive species and UV radiation, whose decontamination potential for free-living, planktonic micro-organisms is well established. In this study, biofilms were produced using Chromobacterium violaceum, a Gram-negative bacterium present in soil and water and used in this study as a model organism. Biofilms were subjected to an atmospheric pressure plasma jet for different exposure times. Our results show that 99.6% of culturable cells are inactivated after a 5 min treatment. The survivor curve shows double-slope kinetics with a rapid initial decline in c.f.u. ml(-1) followed by a much slower decline with D values that are longer than those for the inactivation of planktonic organisms, suggesting a more complex inactivation mechanism for biofilms. DNA and ATP determinations together with atomic force microscopy and fluorescence microscopy show that non-culturable cells are still alive after short plasma exposure times. These results indicate the potential of plasma for biofilm inactivation and suggest that cells go through a sequential set of physiological and morphological changes before inactivation.