Diverse pathogens can potentially persist and proliferate in reclaimed water distribution systems (RWDSs). The goal of this study was to evaluate interactive effects of reclaimed water treatments and water age on persistence and proliferation of multiple fecal (e.g., Klebsiella, Enterobacter) and non-fecal (e.g., Legionella, mycobacteria) gene markers in RWDSs. Six laboratory-scale RWDSs were operated in parallel receiving the influent with or without biologically active carbon (BAC) filtration + chlorination, chloramination, or no disinfectant residual. After 3 years of operation, the RWDSs were subject to sacrificial sampling and shotgun metagenomic sequencing. We developed an in-house metagenome-derived pathogen quantification pipeline, validated by quantitative polymerase chain reaction and mock community analysis, to estimate changes in abundance of ∼30 genera containing waterborne pathogens. Microbial community composition in the RWDS bulk water, biofilm, and sediments was clearly shaped by BAC filtration, disinfectant conditions, and water age. Key commonalities were noted in the ecological niches occupied by fecal pathogen markers in the RWDSs, while non-fecal pathogen markers were more varied in their distribution. BAC-filtration + chlorine was found to most effectively control the widest range of target genera. However, filtration alone or chlorine secondary disinfection alone resulted in proliferation of some of these genera containing waterborne pathogens.

中文翻译：

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绘制非饮用水再利用分配系统中病原体持久性和增殖的地形图：生物过滤、消毒和水龄的相互作用

不同的病原体可能会在再生水分配系统 (RWDS) 中持续存在和增殖。本研究的目的是评估再生水处理和水龄对多种粪便（例如克雷伯氏菌、肠杆菌）和非粪便（例如军团菌）的持久性和增殖的交互影响。, 分枝杆菌) 基因标记在 RWDSs。六个实验室规模的 RWDS 并行运行，接收有或没有生物活性炭 (BAC) 过滤 + 氯化、氯胺化或无消毒剂残留的进水。运行 3 年后，RWDS 接受了牺牲采样和鸟枪宏基因组测序。我们开发了一个内部宏基因组衍生的病原体定量管道，通过定量聚合酶链反应和模拟群落分析进行验证，以估计~30 个含有水源性病原体的属的丰度变化。RWDS 散装水、生物膜和沉积物中的微生物群落组成明显受 BAC 过滤、消毒剂条件和水龄的影响。在 RWDS 中粪便病原体标记占据的生态位中注意到了关键的共性，而非粪便病原体标志物的分布则更加多样化。发现 BAC 过滤 + 氯最有效地控制最广泛的目标属。然而，单独的过滤或单独的氯二次消毒导致其中一些含有水传播病原体的属的增殖。