摘要

       了解抗生素抗性基因 (ARG) 在饮用水处理过程中的分布情况非常重要，因为它们具有潜在的公共卫生风险。对黄河中典型的饮用水处理过程中 ARGs 的发生和分布知之甚少，例如在黄河的沉淀池 (SSR) 和饮用水处理厂 (DWTP)，尤其是在流域规模。本研究采用实时定量聚合酶链反应 (qPCR) 方法对黄河沿线 6 个城市 SSR 进水（河水）和出水（源水）和污水处理厂成品水的 ARG 分析进行了研究。 16S rRNA 基因测序。检测到17个ARGs和2个移动遗传元件（MGEs），其中aadE、strA、strB、tetA、sulII、intl1和Tn916的检出率很高（超过80%）。 ARGs 的绝对丰度（基因拷贝数/mL 水）普遍被 SSRs 和 DWTPs 降低，但 ARGs 的相对丰度（基因拷贝数/16S rRNA 基因）没有观察到减少。未观察到 ARG 和细菌的空间分布。细菌属的分布在不同水型样品中聚集成四种主要模式。细菌属 Pseudomonas、Massilia、Acinetobacter、Sphingomonas、Methylobacterium和 Brevundimonas 在成品水中占主导地位，通过网络分析推测 Brevundimonas 和 Methylobacterium 是两种 ARG（strA 和 strB）的潜在宿主。这两个属的富集，可能是由消毒过程的选择引起的，可能导致成品水中 ARGs 的相对丰度更高。这项研究提供了对流域规模饮用水处理过程中 ARGs 潜在风险的见解和有效评估。

       Understanding how antibiotic resistance genes (ARGs) are distributed in drinking water treatment processes is important due to their potential public health risk. Little is known about the occurrence and distribution of ARGs in typical drinking water treatment processes, such as sand settling reservoirs (SSRs) and drinking water treatment plants (DWTPs), in the Yellow River, especially at the catchment scale. In this study, ARG profiling was investigated from water samples of influent (river water) and effluent (source water) of SSRs and finished water of DWTPs in six cities along the Yellow River catchment using real-time quantitative polymerase chain reaction (qPCR) and 16S rRNA gene sequencing. Seventeen ARGs and two mobile genetic elements (MGEs) were detected, among which aadE, strA, strB, tetA, sulII, intl1, and Tn916 had high detection rates (over 80%). The absolute abundances (gene copies/mL of water) of ARGs were reduced by the SSRs and DWTPs generally, but no reductions were observed for the relative abundances (gene copies/16S rRNA gene) of ARGs. Spatial distributions of ARGs and bacteria were not observed. The distribution of bacterial genera was clustered into four dominant patterns in different water type samples. The bacterial genera Pseudomonas, Massilia, Acinetobacter, Sphingomonas, Methylobacterium, and Brevundimonas dominated the finished water, with Brevundimonas and Methylobacterium being speculated to be potential hosts for two ARGs (strA and strB) through network analysis. The enrichment of these two genera, likely caused by selection of disinfection process, may contribute to the higher relative abundance of ARGs in finished water. This study provides insight and effective assessment of the potential risk of ARGs in drinking water treatment processes at the catchment scale.

https://www.mdpi.com/2073-4441/10/3/246