Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
Water Res. 2021 Jul 15;200:117205. doi: 10.1016/j.watres.2021.117205. Epub 2021 May 6.
Dental unit water systems are prone to biofilm formation. During use of the dental unit, clumps of biofilm slough off and can subsequently be aerosolized and inhaled by both patient and staff, potentially causing infections. The aim of this study was to determine the microbial load and microbiome of dental unit water, in the Netherlands, and the factors influencing these parameters. In total, 226 dental units were sampled and heterotrophic plate counts (HPC) were determined on the traditional effluent sample. Of all dental units, 61% exceeded the recommended microbiological guidelines of 100 colony forming units per milliliter. In addition, the microbiome, with additional q-PCR analysis for specific species, was determined on an effluent sample taken immediately after an overnight stagnancy period, in which the biofilm is in its relaxed state. These relaxed biofilm samples showed that each dental unit had a unique microbiome. Legionella spp., amoeba and fungi were found in 71%, 43% and 98% of all units, respectively. The presence of amoeba was positively associated with nine bacterial biomarkers and correlated positively with bacterial and fungal DNA and Legionella spp. concentrations, but not with HPC. Only when adhering to disinfection protocols, statistically significant effects on the microbial load and microbiome were seen. The relaxed biofilm sample, in combination with molecular techniques gives better insight in the presence of opportunistic pathogens when compared to the heterotrophic plate counts. Infection control measures should focus on biofilm analysis and control in order to guarantee patient safety.
牙科设备水系统容易形成生物膜。在使用牙科设备时，生物膜会脱落并随后被雾化，被患者和工作人员吸入，从而可能导致感染。本研究的目的是确定荷兰牙科设备水中的微生物负荷和微生物组，以及影响这些参数的因素。共采集了 226 个牙科设备样本，并对传统的污水样本进行了异养平板计数（HPC）。所有牙科设备中，有 61%超过了 100 菌落形成单位/毫升的推荐微生物学标准。此外，还对经过一夜静置后（此时生物膜处于松弛状态）采集的污水样本进行了微生物组分析，并采用特定物种的 q-PCR 分析进行了补充。这些松弛的生物膜样本表明，每个牙科设备都有其独特的微生物组。军团菌属、变形虫和真菌分别存在于 71%、43%和 98%的设备中。变形虫的存在与 9 种细菌生物标志物呈正相关，与细菌和真菌 DNA 以及军团菌属浓度呈正相关，但与 HPC 无关。只有当严格遵守消毒方案时，才会对微生物负荷和微生物组产生统计学上的显著影响。与异养平板计数相比，松弛生物膜样本与分子技术相结合，能更好地了解机会性病原体的存在。感染控制措施应侧重于生物膜分析和控制，以保证患者安全。
