Effect of electrical energy on the efficacy of biofilm treatment using the bioelectric effect
Effect of electrical energy on the efficacy of biofilm treatment using the bioelectric effect
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DOI：
10.1038/npjbiofilms.2015.16
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发表时间：
2015-01-01
影响因子：
9.2
通讯作者：
Ghodssi, Reza
中科院分区：
文献类型：
--
作者：
Kim, Young Wook;Subramanian, Sowmya;Ghodssi, Reza
背景/目标：使用电场与小剂量抗生素相结合来增强生物膜的治疗被称为“生物电效应”（BE）。过去二十年来，文献报道了交流和直流场的不同作用机制。在这项工作中，我们首次研究了电能与大肠杆菌K-12 W3110生物膜生物电效应治疗效果之间的相关性。方法：通过对成熟的大肠杆菌生物膜施加不同幅度的交流（AC）、直流（DC）和叠加（SP）电位进行深入研究。在生物膜成熟24小时后，将电场与抗生素庆大霉素(10μg/ml)联合应用24小时。使用结晶紫测定法、菌落形成单位法和荧光显微镜对生物膜进行分析。 结果：结果显示，对于电压 < 1 V，等效能量（方差分析 (ANOVA) P> 0.05）的基于 DC、AC 和 SP 的 BE 处理之间的治疗功效没有统计学差异。我们还证明，通过结晶紫染色法和菌落形成单位测定法测量的 BE 处理功效与所施加的电能成正比。 （方差分析 P < 0.05）。我们进一步验证了治疗效果与 BE 治疗能量呈线性变化 (r(2) = 0.984)。因此，我们的结果表明，在电势低于介质电解电压的情况下，电信号的能量是决定 BE 治疗功效的主要因素。 结论：我们的结果表明，电信号的能量，而不是电信号的类型（交流、直流或 SP），是决定 BE 治疗功效的关键。我们预计这一观察将为进一步了解 BE 处理方法的作用机制铺平道路，并可能为使用电场治疗细菌生物膜打开新的大门。
BACKGROUND/OBJECTIVES: The use of electric fields in combination with small doses of antibiotics for enhanced treatment of biofilms is termed the 'bioelectric effect' (BE). Different mechanisms of action for the AC and DC fields have been reported in the literature over the last two decades. In this work, we conduct the first study on the correlation between the electrical energy and the treatment efficacy of the bioelectric effect on Escherichia coli K-12 W3110 biofilms.METHODS: A thorough study was performed through the application of alternating (AC), direct (DC) and superimposed (SP) potentials of different amplitudes on mature E. coli biofilms. The electric fields were applied in combination with the antibiotic gentamicin (10 mu g/ml) over a course of 24 h, after the biofilms had matured for 24 h. The biofilms were analysed using the crystal violet assay, the colony-forming unit method and fluorescence microscopy.RESULTS: Results show that there is no statistical difference in treatment efficacy between the DC-, AC- and SP-based BE treatment of equivalent energies (analysis of variance (ANOVA) P> 0.05) for voltages < 1 V. We also demonstrate that the efficacy of the BE treatment as measured by the crystal violet staining method and colony-forming unit assay is proportional to the electrical energy applied (ANOVA P < 0.05). We further verify that the treatment efficacy varies linearly with the energy of the BE treatment (r(2) = 0.984). Our results thus suggest that the energy of the electrical signal is the primary factor in determining the efficacy of the BE treatment, at potentials less than the media electrolysis voltage.CONCLUSIONS: Our results demonstrate that the energy of the electrical signal, and not the type of electrical signal (AC or DC or SP), is the key to determine the efficacy of the BE treatment. We anticipate that this observation will pave the way for further understanding of the mechanism of action of the BE treatment method and may open new doors to the use of electric fields in the treatment of bacterial biofilms.