Droste Nahla C, Hummert Mareike, Leenders Paul, Mellmann Alexander, Becker Karsten, Kuczius Thorsten
Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany.
VitalFluid BV, High Tech Campus 25-5, 5656 AE Eindhoven, The Netherlands.
Pathogens. 2024 Jun 24;13(7):535. doi: 10.3390/pathogens13070535.
Plasma-activated water (PAW) generated from tap water has gained attention as a disinfectant when used directly in its pure form. Little is known about the application of PAW for bacterial inactivation in aqueous environments because its use in fluids results in dilutions. We investigated the effect of PAW in aqueous suspensions simulating such dilutions, and we focused on the minimal addition of PAW volumes to bacterial aqueous suspensions still resulting in high inactivation rates. The antimicrobial effect was highly dependent on the activation of PAW. An increase in activation power from 90 to 100 W resulted in a greater microbial reduction with an identical 10 min activation time. The susceptibility to PAW dilutions was analyzed in detail regarding nine Gram-negative species out of and other waterborne microorganisms as well as four Gram-positive species present in two different matrices, in saline and in tap water, at high concentrations simulating massive contamination situations. For this purpose, the PAW activation setting of 90 W and 30 min was defined in order to be able to differentiate the limitations of inactivation in individual bacterial species. The Gram-negatives in saline demonstrated susceptibility when one volume unit of PAW was added. However, twice the PAW volume was necessary for inactivation when bacteria were present in tap water. Gram-positive microorganisms were more robust, indicated by prolonged contact times before inactivation. Our results indicate that PAW can be used for bacterial decontamination processes in aqueous environments when added in surplus. Optimized activation settings such as electric power to generate PAW and the contact times to the samples increase the effect of the inactivation a wide range of bacteria, regardless of their resistance profiles.
由自来水产生的等离子体活化水（PAW）以其纯净形式直接用作消毒剂时受到了关注。由于PAW在液体中的使用会导致稀释，因此对于其在水性环境中用于细菌灭活的应用了解甚少。我们研究了PAW在模拟此类稀释的水性悬浮液中的效果，并专注于向细菌水性悬浮液中添加最少体积的PAW仍能产生高灭活率的情况。抗菌效果高度依赖于PAW的活化。在相同的10分钟活化时间下，活化功率从90瓦增加到100瓦会导致更大程度的微生物减少。我们详细分析了在模拟大量污染情况的高浓度下，两种不同基质（盐水和自来水）中存在的9种革兰氏阴性菌和其他水传播微生物以及4种革兰氏阳性菌对PAW稀释的敏感性。为此，定义了90瓦和30分钟的PAW活化设置，以便能够区分各个细菌物种灭活的局限性。在盐水中添加一个体积单位的PAW时，革兰氏阴性菌表现出敏感性。然而，当细菌存在于自来水中时，灭活需要两倍体积的PAW。革兰氏阳性微生物更具抗性，这表现为灭活前需要更长的接触时间。我们的结果表明，当过量添加时PAW可用于水性环境中的细菌去污过程。优化的活化设置，如产生PAW的电功率和与样品的接触时间，可提高对多种细菌的灭活效果，而不论它们的抗性特征如何。
