Department of Civil, Environmental, and Geo-Engineering , University of Minnesota , 500 Pillsbury Dr. SE , Minneapolis , Minnesota 55455 , United States.
Department of Civil and Environmental Engineering , Norwegian University of Science and Technology , S.P. Andersens veg 5 , 7491 Trondheim , Norway.
Environ Sci Technol. 2019 Aug 6;53(15):8563-8573. doi: 10.1021/acs.est.9b01945. Epub 2019 Jul 22.
Nontuberculous mycobacteria (NTM) are frequently found in chloraminated drinking water distribution systems (DWDSs) due to their chloramine tolerance. NTM were investigated in the water-main biofilms and drinking water of a chloraminated DWDS in the United States (initial chloramine residual = 3.8 ± 0.1 mg L) and a DWDS in Norway with minimal residual disinfectant (0.08 ± 0.01 mg L). Total mycobacteria and complex (MAC) were quantified by qPCR targeting, respectively, genes and the internal transcribed spacer region. Mycobacteria concentrations in drinking water did not differ between the two systems ( = 0.09; up to 6 × 10 copies L) but were higher in the biofilms from the chloraminated DWDS ( = 5 × 10; up to 5 × 10 copies cm). MAC were not detected in either system. Sequencing of mycobacterial genes indicated that the chloraminated DWDS lacked diversity and consisted almost exclusively of . In contrast, there were various novel mycobacteria in the no-residual DWDS. Finally, - and -like 16S rRNA genes were often detected simultaneously, though without correlation as previously observed. We conclude that, though residual chloramine may increase mycobacterial biomass in a DWDS, it may also decrease mycobacterial diversity.
非结核分枝杆菌（NTM）由于其对氯胺的耐受性，经常在加氯饮用水分配系统（DWDS）中被发现。在美国的一个加氯 DWDS（初始氯胺残留量为 3.8 ± 0.1mg/L）和挪威一个残余消毒剂最小的 DWDS（0.08 ± 0.01mg/L）中，研究了主供水管生物膜和饮用水中的 NTM。通过分别针对基因和内部转录间隔区的 qPCR 定量了总分枝杆菌和复合分枝杆菌（MAC）。两个系统的饮用水中分枝杆菌浓度没有差异（ = 0.09；高达 6×10 拷贝/L），但加氯 DWDS 的生物膜中的分枝杆菌浓度更高（ = 5×10；高达 5×10 拷贝/cm）。在两个系统中均未检测到 MAC。分枝杆菌基因的测序表明，加氯 DWDS 缺乏多样性，几乎完全由 组成。相比之下，在无残余 DWDS 中存在各种新型分枝杆菌。最后，-和-样 16S rRNA 基因经常同时被检测到，尽管没有像以前观察到的那样存在相关性。我们的结论是，尽管残余氯胺可能会增加 DWDS 中的分枝杆菌生物量，但它也可能降低分枝杆菌的多样性。
