摘要

    这项研究的目的是评估包括二级处理和加氯在内的常规废水处理工艺对去除抗生素抗性基因（ARG）和抗生素抗性细菌（ARB）的影响，并评估ARGs与它们潜在宿主之间的关系。每个治疗过程。结果表明，亚抑菌浓度（<8 mg / L）的氯化导致消毒液中的ARB数增加。 qPCR分析表明，二级处理增加了残留细菌中ARG的相对丰度，而消毒有效地降低了这些基因的相对丰度。元基因组学分析显示，携带ARGs的主要细菌属发生了显着变化。在整个处理过程中，分别识别出48、95和80属ARG携带者为主要污水，次要污水和消毒污水。还发现，二级处理增加了潜在的ARG宿主的多样性，而二级处理和氯化都在属水平上拓宽了某些ARG的宿主范围，这可能归因于抗生素抗性通过水平转移在整个细菌属中的扩散。这项研究突出了人们日益关注的一个问题，即废水处理厂（WWTP）可能通过将这种效应与特定的处理阶段相关联，并将其与细菌宿主相关联来传播ARG。

    The aim of this study was to evaluate the impacts of conventional wastewater treatment processes including secondary treatment and chlorination on the removal of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB), and to assess the association of ARGs with their potential hosts in each treatment process. The results showed chlorination with subinhibitory concentration (<8 mg/L) resulted in an increased ARB number in the disinfection effluent. qPCR analysis indicated secondary treatment increased relative abundance of ARGs in remaining bacteria whereas disinfection reduced the relative abundance of those genes effectively. Metagenomic analysis revealed a significant shift of dominating bacterial genera harboring ARGs. Along the treatment train, 48, 95 and 80 genera were identified to be the ARG carriers in primary effluent, secondary effluent, and disinfection effluent, respectively. It was also found that secondary treatment increased the diversity of potential ARG hosts while both secondary treatment and chlorination broadened the host range of some ARGs at the genus level, which may be attributed to the spread of antibiotic resistance across bacterial genera through horizontal transfer. This study highlights the growing concerns that wastewater treatment plants (WWTPs) may disseminate ARGs by associating this effect to specific treatment stages and by correlating ARGs with their bacterial hosts.

    https://www.sciencedirect.com/science/article/abs/pii/S0045653521000333