Yin Xiaole, Yang Yu, Deng Yu, Huang Yue, Li Liguan, Chan Lilian Y L, Zhang Tong
Environmental Microbiome Engineering and Biotechnology Laboratory, Center for Environmental Engineering Research, Department of Civil Engineering, The University of Hong Kong, Hong Kong, China.
High Performance Computing Team, Information Technology Services, The University of Hong Kong, Hong Kong, China.
Water Res. 2022 Feb 1;209:117885. doi: 10.1016/j.watres.2021.117885. Epub 2021 Nov 22.
Wastewater treatment plants (WWTPs) are regarded as critical points in disseminating antibiotic resistance genes (ARGs). In particular, the discharging effluents from WWTPs generally bring downstream catchment areas exogenous ARGs and resistant bacteria. However, there lacks a sufficient assessment of the resistome and mobilome in effluents. In this study, a consecutive monthly sampling was conducted over 13 months in three Hong Kong (HK) WWTPs for metagenomic sequencing. Prevalence information of ARGs and mobile genetic elements (MGEs) was compared with counterparts in effluents from cities of North America, South America, Europe, and Asia. Moreover, a publicly accessible platform integrating the exposure ranking scheme, which was based on the global archive of ARG abundance, and a readily implementable online pipeline was developed to benefit communication in academia and government consultancy. Results demonstrated HK WWTPs were featured high ARG removal efficiency of 2.34-2.43 log reduction rate, and effluents were ranked in moderate levels of Level 2 and Level 3 in the exposure prioritizing scheme based on total ARG abundance. Moreover, absolute quantification of temporal variations of effluent resistome disclosed distinct changes over time among varied ARG types which were associated with prevalently used antibiotics, including quinolone and sulfonamide. This reinforces the need for real-time management of WWTP systems. Notably, ARGs of anthropogenic prevalence, high mobility, and potential pathogenicity were found to be present in HK effluents, drawing attention to the necessity for improved risk management. In addition, source tracking of effluent resistome and structural equation model analysis was conducted to explore the disparity in ARG abundance and diversity in different samples. The discovery of this study and the recommendation of a comprehensive exposure assessment will facilitate decision-making in resistome management in WWTPs to reduce the ARG and antibiotic resistant bacteria (ARB) contamination in the receiving environments.
污水处理厂被视为传播抗生素抗性基因（ARGs）的关键点。特别是，污水处理厂排放的废水通常会给下游集水区带来外源ARGs和抗性细菌。然而，目前对废水中的抗性组和可移动基因组缺乏充分评估。在本研究中，对香港三个污水处理厂进行了为期13个月的连续月度采样，用于宏基因组测序。将ARGs和移动遗传元件（MGEs）的流行信息与来自北美、南美、欧洲和亚洲城市的废水样本进行了比较。此外，还开发了一个公开可用的平台，该平台整合了基于ARG丰度全球档案的暴露排名方案以及一个易于实施的在线流程，以促进学术界和政府咨询机构之间交流。结果表明，香港污水处理厂对ARGs的去除效率较高，降低率为2.34-2.43个对数级，且根据总ARG丰度，排放废水在暴露优先级方案中被列为中等水平的2级和3级。此外，对废水抗性组时间变化的绝对定量揭示了不同ARG类型随时间的明显变化，这些变化与常用抗生素（包括喹诺酮和磺胺类）有关。这进一步强调了对污水处理系统进行实时管理的必要性。值得注意的是，在香港的排放废水中发现了具有人为流行、高移动性和潜在致病性的ARGs，这凸显了加强风险管理的必要性。此外，还进行了废水抗性组的溯源和结构方程模型分析，以探索不同样本中ARG丰度和多样性的差异。本研究的发现以及全面暴露评估的建议将有助于污水处理厂抗性组管理的决策，以减少受纳环境中的ARG和抗生素抗性细菌（ARB）污染。
