摘要
      抗生素和ARGs的时间变化，以及住院患者的日常日程安排对其在医院废水（HWW）中经常发生的影响，以前都不清楚。在这项研究中，住院部处理前和处理后的废水（水力停留时间=8小时）在当天和周内收集。分析HWW中抗生素/代谢产物和ARGs的绝对浓度，以研究其发生水平的时间变化。氟喹诺酮类药物是住院部使用的主要药物（污水中681.30–881.66 ng/mL），也是消毒池出口的主要污染物（538.29–671.47 ng/mL）。大多数抗生素和ARGs的昼夜变化在19:00达到峰值，而最大的变化发生在周末。氨基糖苷类耐药基因（AMRGs，21.6–23000拷贝/mL）和β-内酰胺类耐药基因，1.24–8500拷贝/mL，分别是处理前后的显性ARGs（p<0.05）。大多数抗生素和ARGs以及整合酶基因intI1和16S rRNA基因的显着去除率（>50%），被发现仅经过氯化物消毒过程，这表明独立废水处理过程的必要性。同时，抗生素、ARGs、intI1和16S rRNA之间的统计学显著相关性（p<0.05）表明，ARGs在医院污水中的选择性压力、水平转移和垂直传播的风险是有保证的。主成分分析（PCA）表明，住院患者的日常日程安排和废水处理过程会显著导致HWW中抗生素和ARG水平的波动，这表明它们应被视为环境监测的影响因素。这项研究首次证明了抗生素和ARGs在半封闭区的丰度和传播的时间变化，并为相关生态风险和人类健康评估的发展提供了新的见解。
Abstract
The temporal variation of antibiotics and ARGs as well as the impact of daily schedule of inpatients on their regular occurrence in hospital wastewater (HWW) were previously obscure. In this study, the wastewater of the inpatient department pre- and posttreatment (hydraulic retention time = 8 h) was collected intraday and intraweek. The absolute concentrations of antibiotics/metabolites and ARGs in HWW were analyzed to investigate the temporal variations of their occurrence levels. Fluoroquinolones were the predominant drugs used in the inpatient department (681.30–881.66 ng/mL in the effluent) and the main contaminant in the outlet of the disinfection pond (538.29–671.47 ng/mL). Diurnal variations peaked at 19:00 for most antibiotics and ARGs, while the maximum of them occurred on weekends. Aminoglycoside resistance genes (AMRGs, 21.6–23000 copies/mL) and β-lactam resistance genes (BLGRs, 1.24–8500 copies/mL) were the dominant ARGs before and after treatment processing, respectively (p < 0.05). The significant removal rates (>50%) of most antibiotics and ARGs, as well as the integrase gene intI1 and 16S rRNA gene, were found to be subjected solely to the chloride disinfection process, suggesting the necessity of the self-contained wastewater treatment process. Meanwhile, the statistically significant correlation among antibiotics, ARGs, intI1, and 16S rRNA (p < 0.05) demonstrated that the risk of selective pressure, horizontal transfer and vertical propagation of ARGs in the effluent of the hospital was warranted. Principal component analysis (PCA) showed that the daily schedule of inpatients and wastewater treatment processes could markedly induce fluctuations in antibiotic and ARG levels in HWW, indicating that they should be considered an impact factor for environmental monitoring. This study demonstrated for the first time the temporal variations in the abundance and dissemination of antibiotics and ARGs in a semiclosed zone and provided new insight into the development of assessments of the associated ecological risk and human health.

https://www.sciencedirect.com/science/article/abs/pii/S0045653521038790