Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Moscow, Russia.
Joint Institute of High Temperatures, Russian Academy of Sciences, Moscow, Russia.
J Med Microbiol. 2011 Jan;60(Pt 1):75-83. doi: 10.1099/jmm.0.020263-0. Epub 2010 Sep 9.
Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 10(5) c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17 % survival of the initial 10(5) c.f.u. after a 5 min plasma treatment. Staphylococcus aureus had a strain-dependent resistance with 0 and 10 % survival from 10(5) c.f.u. of the Sa 78 and ATCC 6538 strains, respectively. Staphylococcus epidermidis and Enterococcus faecium had medium resistance. Non-ionized argon gas was not bactericidal. Biofilms partly protected bacteria, with the efficiency of protection dependent on biofilm thickness. Bacteria in deeper biofilm layers survived better after the plasma treatment. A rat model of a superficial slash wound infected with P. aeruginosa and the plasma-sensitive Staphylococcus aureus strain Sa 78 was used to assess the efficiency of argon plasma treatment. A 10 min treatment significantly reduced bacterial loads on the wound surface. A 5-day course of daily plasma treatments eliminated P. aeruginosa from the plasma-treated animals 2 days earlier than from the control ones. A statistically significant increase in the rate of wound closure was observed in plasma-treated animals after the third day of the course. Wound healing in plasma-treated animals slowed down after the course had been completed. Overall, the results show considerable potential for non-thermal argon plasma in eliminating pathogenic bacteria from biofilms and wound surfaces.
非热（低温）等离子体作为一种替代方法，正在被深入研究，以控制因天然病原体或生物膜耐药性而导致化学药物效果减弱的浅表伤口和皮肤感染。本研究的目的是测试致病菌对非热氩等离子体的个体敏感性，并测量等离子体处理对生物膜和伤口表面细菌的有效性。总体而言，革兰氏阴性菌比革兰氏阳性菌对等离子体处理更敏感。对于革兰氏阴性菌铜绿假单胞菌、洋葱伯克霍尔德菌和大肠杆菌，在 5 分钟等离子体处理后，初始 10（5）cfu 中没有存活的细菌。革兰氏阳性菌的敏感性具有种属和菌株特异性。化脓链球菌是最具抗性的，在 5 分钟等离子体处理后，初始 10（5）cfu 的存活率为 17%。金黄色葡萄球菌的抗性具有菌株依赖性，Sa 78 和 ATCC 6538 株的初始 10（5）cfu 的存活率分别为 0%和 10%。表皮葡萄球菌和粪肠球菌具有中等抗性。未离解的氩气没有杀菌作用。生物膜部分保护细菌，保护效率取决于生物膜的厚度。等离子体处理后，深层生物膜层中的细菌存活得更好。使用铜绿假单胞菌和对等离子体敏感的金黄色葡萄球菌菌株 Sa 78 感染的大鼠浅表划伤伤口模型来评估氩等离子体处理的效率。10 分钟的处理可显著降低伤口表面的细菌负荷。与对照组相比，每天等离子体处理 5 天的疗程可使等离子体处理动物中的铜绿假单胞菌提前 2 天消除。在疗程的第三天观察到等离子体处理动物的伤口闭合率有统计学意义的增加。疗程完成后，等离子体处理动物的伤口愈合速度减慢。总的来说，结果表明非热氩等离子体在从生物膜和伤口表面消除致病菌方面具有相当大的潜力。
