摘要

     在这项研究中，我们比较了两种废水处理系统对抗生素抗性细菌（ARB）和抗生素抗性基因（ARG）的去除情况：传统废水处理系统（由一个滴滤器和一个活性污泥工艺组成）和藻类系统，使用一种极端藻类，硫藻。结果表明，与常规处理系统相比，藻类系统更能有效地降低废水中红霉素和磺胺甲恶唑耐药菌的浓度。两种处理系统的细菌总数和ARGs均呈下降趋势。然而，在常规体系中，存活细菌中大部分ARG（qnrA、qnrB、qnrS、sul1）和intI1的相对比值增加；而藻类体系则使存活细菌中qnrA、qnrS、tetW和intⅠ1的相对丰度降低。噬菌体在两种体系中的基因水平转移转移（HGT）中的作用表明，噬菌体中ARG的绝对丰度与细菌中ARG的相对丰度呈正相关。在噬菌体阶段，5个可检测基因（qnrS、tetW、sul1和intI1）中的4个在藻类系统中显著减少，这表明噬菌体介导的ARG在藻类系统中的基因转移减少。研究结果表明，藻类废水处理系统在降低ARGs和ARB、减少抗生素对环境的耐药性方面是可行的。

     In this study, we compared removal of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in two wastewater treatment systems fed with the same primary effluent: a conventional wastewater treatment system (consisting of a trickling filter followed by an activated sludge process) versus an algal-based system, employing an extremophilic alga, Galdieria sulphuraria. Our results demonstrated that the algal system can reduce concentrations of erythromycin- and sulfamethoxazole-resistant bacteria in the effluent more effectively than the conventional treatment system. A decreasing trend of total bacteria and ARGs was observed in both the treatment systems. However, the relative ratio of most ARGs (qnrA, qnrB, qnrS, sul1) and intI1 in the surviving bacteria increased in the conventional system; whereas, the algal system reduced more of the relative abundance of qnrA, qnrS, tetW and intⅠ1 in the surviving bacteria. The role of bacteriophages in horizontal gene transfer (HGT) of ARGs in the two systems was indicated by a positive correlation between ARG absolute abundance in bacteriophage and ARG relative abundance in the bacteria. Four of the five detectable genes (qnrS, tetW, sul1 and intI1) were significantly reduced in the algal system in bacteriophage phase which signified a decrease in phage-mediated ARG transfer in the algal system. Results of this study demonstrate the feasibility of the algal-based wastewater treatment system in decreasing ARGs and ARB and in minimizing the spread of antibiotic resistance to the environment.

     https://www.sciencedirect.com/science/article/pii/S0048969719344262