摘要
      为了评估与废水处理厂（WWTP）相关的抗生素耐药性的环境传播威胁，需要评估废水处理过程中抗生素耐药性基因（ARGs）的去除效率。样本收集策略是研究设计中经常被忽视的一个因素，大多数关于废水中ARGs的研究都是抓取采样。在这里，我们假设废水取样（即抓斗取样和复合取样）会影响WWTP中观察到的ARG浓度和计算出的去除率。我们比较了基于几种基因的两种不同采样方法计算的去除率，包括一些临床相关的ARGs（blaNDM-1、blaOXA-1、MCR-1、MCR-5、MCR-10和qnrA）。我们进行了夏季和冬季24小时的采样活动，每2小时从进水、二次出水和最终出水中采集一次抓取样本。基于12个抓取样本计算的每个目标基因的快照去除率在冬季波动0.5–1.6 log，在夏季波动0.9–2.7 log，表明日变化。总体而言，对于每个靶基因，基于24小时复合样本计算的去除率大致等于12个快照去除率的中位数。我们的研究证实了使用复合样品监测废水中ARGs的重要性。
Abstract
To evaluate the threat of the environmental dissemination of antibiotic resistance associated with wastewater treatment plants (WWTPs), the removal efficiency of antibiotic resistance genes (ARGs) during wastewater treatment needs to be assessed. The sample collection strategy is one factor that is often overlooked in study design and most studies on ARGs in wastewater perform grab sampling. Here, we hypothesized that wastewater sampling (i.e., grab and composite sampling) influences the observed ARG concentrations and calculated removal rates across WWTPs. We compared the removal rates calculated based on the two different sampling methods for several genes, including some clinically relevant ARGs (blaNDM-1, blaOXA-1, MCR-1, MCR-5, MCR-10, and qnrA). We conducted summer and winter 24 h sampling campaigns where grab samples were collected every 2 h from the influent, secondary effluent, and final effluent. The snapshot removal rate of each target gene calculated based on the 12 grab samples fluctuated by 0.5–1.6 log in the winter and 0.9–2.7 log in the summer, indicating diurnal variation. Overall, for each target gene, the removal rates calculated based on 24 h composite samples were approximately equal to the median of the 12 snapshot removal rates. Our study confirms the importance of using composite samples to monitor ARGs in wastewater.

https://pubs.acs.org/doi/full/10.1021/acsestwater.2c00467