Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, College of Water Sciences, Beijing Normal University, Beijing 100875, China.
Beijing BHZQ Environmental Engineering Technology Co., LTD, Beijing 100176, China.
Sci Total Environ. 2022 Sep 10;838(Pt 3):156426. doi: 10.1016/j.scitotenv.2022.156426. Epub 2022 Jun 2.
The reuse of urban reclaimed water is conducive to alleviate the current serious shortage of water resources. However, antibiotic resistance genes (ARGs) in reclaimed water have received widespread attention due to their potential risks to public health. Deciphering the fate of ARGs in reclaimed water benefits the development of effective strategies to control resistome risk and guarantees the safety of water supply of reclaimed systems. In this study, the characteristics of ARGs in an integrated reclaimed water system (sewage treatment plant-constructed wetland, STP-CW) in Beijing (China) have been identified using metagenomic assembly-based analysis, as well as the combined effect of the STP-CW system on the reduction of antibiotic resistome. Results showed a total of 29 ARG types and 813 subtypes were found in the reclaimed water system. As expected, the STP-CW system improved the removal of ARGs, and about 58% of ARG subtypes were removed from the effluent of the integrated STP-CW system, which exceeded 43% for the STP system and 37% for the CW system. Although the STP-CW system had a great removal on ARGs, abundant and diverse ARGs were still found in the downstream river. Importantly, network analysis revealed the co-occurrence of ARGs, mobile genetic elements and virulence factors in the downstream water, implying potential resistome dissemination risk in the environment. Source identification with SourceTracker showed the STP-effluent was the largest contributor of ARGs in the downstream river, with a contribution of 45%. Overall, the integrated STP-CW system presented a combined effect on the reduction of antibiotic resistome, however, the resistome dissemination risk was still non-negligible in the downstream reclaimed water. This study provides a comprehensive analysis on the fate of ARGs in the STP-CW-river system, which would benefit the development of effective strategies to control resistome risk for the reuse of reclaimed water.
城市再生水的再利用有利于缓解当前严重的水资源短缺问题。然而，由于其对公众健康的潜在风险，再生水中的抗生素抗性基因（ARGs）受到了广泛关注。解析 ARGs 在再生水中的归宿有利于制定有效的控制抗性风险策略，并保证再生水系统供水的安全性。在本研究中，采用基于宏基因组组装的分析方法，对北京（中国）一体化再生水系统（污水处理厂-人工湿地，STP-CW）中 ARGs 的特征进行了鉴定，并研究了 STP-CW 系统对抗生素抗性组的削减作用。结果表明，再生水系统中共发现 29 种 ARG 类型和 813 种亚型。正如预期的那样，STP-CW 系统提高了 ARGs 的去除率，约有 58%的 ARG 亚型从集成 STP-CW 系统的出水中被去除，而 STP 系统和 CW 系统的去除率分别为 43%和 37%。尽管 STP-CW 系统对 ARGs 有很好的去除效果，但在下游河流中仍发现了丰富多样的 ARGs。重要的是，网络分析显示下游水中 ARGs、移动遗传元件和毒力因子的共存，暗示了环境中潜在的抗性组传播风险。SourceTracker 的源识别表明，STP 出水是下游河流中 ARGs 的最大贡献者，贡献率为 45%。总体而言，一体化 STP-CW 系统对减少抗生素抗性组具有综合作用，但在下游再生水中，抗性组的传播风险仍然不可忽视。本研究对 STP-CW-河流系统中 ARGs 的归宿进行了全面分析，这将有助于制定有效的控制抗性风险策略，以实现再生水的再利用。
