摘要
      废水处理厂（WWTP）被认为是传播抗生素抗性基因（ARGs）的关键点。特别是，污水处理厂的排放污水通常会给下游集水区带来外源性ARG和耐药细菌。然而，对废水中的耐药性和流动性缺乏充分的评估。在本研究中，对三个香港污水处理厂进行了为期13个月的连续月度采样，以进行宏基因组测序。将ARGs和可移动遗传元素（MGE）的患病率信息与北美、南美、欧洲和亚洲城市污水中的相应信息进行了比较。此外，还开发了一个可公开访问的平台，该平台集成了基于ARG丰度全球档案的暴露排名方案和一个易于实施的在线管道，以利于学术界和政府咨询机构的沟通。结果表明，香港污水处理厂具有2.34–2.43 log还原率的高ARG去除效率，并且在基于总ARG丰度的暴露优先级方案中，废水被列为2级和3级的中等水平。此外，流出物耐药性随时间变化的绝对量化揭示了不同ARG类型随时间的明显变化，这些ARG类型与广泛使用的抗生素（包括喹诺酮和磺酰胺）有关。这加强了对污水处理厂系统实时管理的需求。值得注意的是，香港污水中存在人为流行、高流动性和潜在致病性的ARGs，这引起了人们对改进风险管理的必要性的关注。此外，还进行了出水抗性的来源跟踪和结构方程模型分析，以探索不同样品中ARG丰度和多样性的差异。这项研究的发现和全面暴露评估的建议将有助于污水处理厂耐药性管理的决策，以减少接收环境中的ARG和抗生素耐药性细菌（ARB）污染。
Abstract
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.

https://www.sciencedirect.com/science/article/abs/pii/S0043135421010794