Facultad de Ciencias Químicas, Universidad Central del Ecuador, 170521 Quito, Ecuador.
Facultad de Medicina. Escuela de Bioanálisis, Universidad Central de Venezuela, 1053 Caracas, Venezuela.
Int J Environ Res Public Health. 2020 Mar 31;17(7):2348. doi: 10.3390/ijerph17072348.
Three cases of severe odontogenic infections due to nontuberculous mycobacteria (NTM) in Venezuela that were directly associated with dental procedures and the finding of dental unit waterlines (DUWLs) in dental offices that were colonized with mycobacteria species was the reason for assessing the water quality of DUWLs in dental offices in two capital cities in South America, namely, Quito and Caracas. The main water supplies and the water from 143 DUWLs in both cities were sampled and especially checked for contamination with NTM. To measure the overall bacteriological quality of the water also the presence of heterotrophic bacteria, coliform bacteria, and was determined. Results showed that respectively 3% and 56% of the DUWLs in Quito and Caracas yielded NTM species (up to 1000 colony-forming units (CFU)/mL). Furthermore, high and unacceptable total viable counts of heterotrophic bacteria and/or coliform bacteria and were detected in 73% of the samples. We conclude that, in both cities, the water in the majority of DUWLs was contaminated with NTM and other potential pathogens, presenting a risk to human health. The detection of NTM in DUWL water with acceptable heterotrophic bacteria counts shows the need to include NTM in water quality testing. Mycobacteria are more resistant to disinfection procedures than other types of vegetative bacteria, and most testing protocols for DUWLs do not assess mycobacteria and thus do not guarantee risk-free water.
委内瑞拉发生三起因非结核分枝杆菌（NTM）引起的严重牙源性感染病例，这些病例均与牙科手术直接相关，且在牙科学术中发现牙单位水线（DUWL）被分枝杆菌属物种定植。这是评估南美洲两个首都城市（厄瓜多尔的基多和委内瑞拉的加拉加斯）牙科学术中 DUWL 水质的原因。主要供水源和两个城市的 143 个 DUWL 中的水均被采样，并特别检查 NTM 的污染情况。为了衡量水的整体细菌质量，还确定了异养细菌、大肠菌群和 的存在情况。结果表明，基多和加拉加斯的 DUWL 中分别有 3%和 56%的 DUWL 产生 NTM 物种（最高达 1000 菌落形成单位（CFU）/mL）。此外，在 73%的样本中检测到高且不可接受的异养细菌和/或大肠菌群和 的总活菌数。我们的结论是，在这两个城市，大多数 DUWL 中的水都被 NTM 和其他潜在的病原体污染，对人类健康构成威胁。在接受的异养细菌计数的 DUWL 水中检测到 NTM 表明需要将 NTM 纳入水质检测中。分枝杆菌比其他类型的植物性细菌更能抵抗消毒程序，并且大多数 DUWL 测试协议都不评估分枝杆菌，因此不能保证水是无风险的。
