Krüger Theresa Isabella Maria, Herzog Susann, Mellmann Alexander, Kuczius Thorsten
Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany.
Microorganisms. 2023 Apr 26;11(5):1123. doi: 10.3390/microorganisms11051123.
Bacterial contamination is a problem in dental unit water lines with the consequence of implementing regular disinfection. In this study, the short-term impact of chlorine dioxide (ClO) treatment was investigated on the microorganisms and , , and . The environmental background was proven as an important factor regarding the tolerance to 0.4 mg/L ClO as saline and phosphate-buffered saline resulted in a higher bacterial reduction than tap water. Gram-positive microorganisms demonstrated higher robustness to ClO than Gram-negative, and microorganisms adapted to tap water showed increased stability compared to cultured cells. At high densities, substantial numbers of bacteria were able to withstand disinfection, whereby the use of 4.6 mg/L ClO increased the inactivation rate. A massive cell decrease occurred within the first 5 minutes with subsequent plateau formation or slowed cell reduction upon further exposure. This biphasic kinetics cannot be explained by a ClO depletion effect alone, because the probability of bacterial subpopulations with increased tolerance should be taken into account, too. Our results prove high disinfection efficiency to microorganisms that were rather found in correlation to the level of bacterial contamination and background solutions than the chosen concentration for ClO treatment itself.
细菌污染是牙科设备水线中的一个问题，因此需要定期进行消毒。在本研究中，研究了二氧化氯（ClO）处理对微生物 、 、 和 的短期影响。事实证明，环境背景是影响对0.4 mg/L ClO耐受性的一个重要因素，因为盐水和磷酸盐缓冲盐水比自来水能使细菌减少得更多。革兰氏阳性微生物对ClO的耐受性高于革兰氏阴性微生物，并且与培养细胞相比，适应自来水的微生物表现出更高的稳定性。在高密度情况下，大量细菌能够承受消毒，因此使用4.6 mg/L ClO可提高灭活率。在最初的5分钟内细胞大量减少，随后形成平台期，或在进一步暴露后细胞减少速度减慢。这种双相动力学不能仅用ClO消耗效应来解释，因为还应考虑耐受性增加的细菌亚群的可能性。我们的结果证明，对于微生物而言，消毒效率很高，这与细菌污染水平和背景溶液有关，而不是与所选的ClO处理浓度本身有关。
