Removal of antibiotic resistance genes in an algal-based wastewater treatment system employing Galdieria sulphuraria: A comparative study
Removal of antibiotic resistance genes in an algal-based wastewater treatment system employing Galdieria sulphuraria: A comparative study
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DOI：
10.1016/j.scitotenv.2019.134435
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发表时间：
2020-04-01
影响因子：
9.8
通讯作者：
Zhang, Yanyan
中科院分区：
文献类型：
--
作者：
Cheng, Xiaoxiao;Delanka-Pedige, Himali M. K.;Zhang, Yanyan
在这项研究中，我们比较了使用相同一级出水的两个废水处理系统中抗生素耐药细菌（ARB）和抗生素耐药基因（ARG）的去除情况：传统废水处理系统（由滴滤器和活性污泥工艺组成）与藻类为基础的系统，采用嗜极端藻类Galdieria sulphuraria。我们的研究结果表明，藻类系统可以降低浓度的红霉素和磺胺甲恶唑耐药细菌的废水比传统的处理系统更有效。在两种处理系统中均观察到细菌总数和ARGs呈下降趋势。然而，大多数ARG（qnrA，qnrB，qnrS，sul1）和intl1在存活的细菌中的相对比例增加在常规系统中，而藻类系统减少更多的qnrA，qnrS，tetW和intl1在存活的细菌中的相对丰度。噬菌体中ARG的绝对丰度和细菌中ARG的相对丰度之间的正相关性表明，在两个系统中的水平基因转移（HGT）的噬菌体的作用。5个可检测基因中的4个（qnrS、tetW、sul1和intl1）在噬菌体阶段的藻类系统中显著减少，这表明藻类系统中噬菌体介导的ARG转移减少。这项研究的结果表明，藻类废水处理系统在减少ARGs和ARB和最大限度地减少抗生素耐药性对环境的传播的可行性。(C)2019 Elsevier B.V.版权所有。
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 intl1 in the surviving bacteria increased in the conventional system; whereas, the algal system reduced more of the relative abundance of qnrA, qnrS, tetW and intl1 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 intl1) 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. (C) 2019 Elsevier B.V. All rights reserved.