摘要

    在环境中传播抗菌素耐药性是一个全球性的健康问题。耐药菌和抗生素抗性基因（ARG）通过废水处理厂（WWTP）的流出物（EFs）不断释放到环境中。因此，需要更好地了解废水处理过程中ARG的选择和命运。因此，我们调查了城市污水处理厂EF在其抵御系统和运动罩的背景下对取水的影响。我们使用基于HiSeq的短读宏基因组学方法来处理WWTP EF以及上游（UP）和下游（DN）河流水域中ARG的动力学和多样性，然后研究质粒介导的ARGs。每个16S rRNA基因拷贝的每个位点ARG的丰度从7.2×10-2到7.4×10-1拷贝不等，EF样品的丰度最高，其次是DN和UP水样品。每个站点的ARG多样性范围从121到686，而EF拥有最多的ARG。 EF和DN样品中通常鉴定出的ARG具有重要的临床意义，而UP样品中却不存在。仅在EF和DN中发现的大量ARG，移动遗传元件（MGE）和质粒重叠群相互之间呈正相关，这表明动植物在ARG在环境中传播中的重要性。此外，质粒介导的ARGs的比例在EF样品中最高，其次是DN和UP样品。这些发现表明，污水处理厂的EF可能是影响接受水的电阻组和运动组的驱动因素。特别是，WWTP EF中质粒介导的ARG含量较高，表明在DN环境中具有较高的透射率。

    Environmental dissemination of antimicrobial resistance is a global health problem. Antimicrobial-resistant bacteria and antibiotic-resistant genes (ARGs) are constantly released into the environment through effluents (EFs) from wastewater treatment plants (WWTPs). Thus, requiring a better understanding of the selection and fate of ARGs in wastewater treatment processes. Therefore, we investigated the impacts of urban WWTP EFs on receiving water in the context of their resistomes and mobilomes. We used a HiSeq-based short read metagenomic approach to address the dynamics and diversity of ARGs in WWTP EF as well as the upstream (UP) and downstream (DN) river waters, followed by an investigation of plasmid-mediated ARGs. The abundance of ARGs at each site varied from 7.2 × 10−2 to 7.4 × 10−1 ARG copies per 16S rRNA gene copy, and EF samples showed the highest abundance, followed by DN and UP water samples. ARG diversity ranged from 121 to 686 types per site, and EF had the most diverse ARGs. Commonly identified ARGs in the EF and DN samples were clinically important and were absent in UP samples. The abundance of ARGs, mobile genetic elements (MGEs), and plasmid contigs found only in EF and DN were positively correlated with each other, indicating the importance of mobilomes in the dissemination of ARGs in the environment. Moreover, the proportions of plasmid-mediated ARGs was highest in the EF samples, followed by the DN and UP samples. These findings suggest that WWTP EF may act as a driving factor shaping the resistomes and mobilomes of receiving waters. In particular, a higher abundance of plasmid-mediated ARGs in WWTP EF suggests higher transmissibility in the DN environment.

    https://www.sciencedirect.com/science/article/abs/pii/S0048969720362847