摘要

      抗微生物耐药性（AMR）是一个严重的公共卫生问题。许多国家已经实施了针对人类和动物的AMR监测计划，但尚未建立监测环境中AMR的计划。1类整合子可以获得对基因盒的抗微生物耐药性基因（ARGs），被提议作为评估人为对AMR影响的候选者。然而，在水生环境中，1类整合子和ARGs之间的关联研究较少，需要进一步阐明。本研究使用高通量定量聚合酶链式反应（HT-qPCR）对东京及其周边地区24条城市河流中ARGs和移动基因元件（MGE）的污染状况进行了表征。还测定了1类整合素整合酶基因（intI1）的丰度和1类整合素基因盒的阵列。每个样本总共检测到9-53个靶基因，它们的丰度随着污水处理厂的污水排放而增加。根据河流和废水样本的HT-qPCR图谱对其进行了分类，表明该方法可用于表征水环境中的污染状况。观察到河流中intI1的流行情况。一些ARG和MGE与intI1呈正相关，表明intI1可以作为监测城市河流中这些ARG和MG的指标。1类整合子基因盒的长读测序显示，在基因盒中存在一到三个ARG。无论样本类型如何，blaGES-24、aadA2和qacH在基因盒中占主导地位。应进一步监测携带这些ARG的1类整合子在水生环境中的来源和传播。Antimicrobial resistance (AMR) is a serious public health concern. Many countries have implemented AMR surveillance programs for humans and animals, but a scheme for monitoring AMR in the environment has not yet been established. Class 1 integrons, which can acquire antimicrobial resistance genes (ARGs) to gene cassettes, were proposed as a candidate to evaluate the anthropogenic impacts on AMR. However, the association between class 1 integrons and ARGs in aquatic environments is less studied and requires further elucidation. This study used high-throughput quantitative polymerase chain reaction (HT-qPCR) to characterize the pollution profiles of ARGs and mobile gene elements (MGEs) in 24 urban rivers in Tokyo and its surrounding area. The abundance of class 1 integron-integrase gene (intI1) and the array of class 1 integron gene cassettes were also determined. In total, 9–53 target genes were detected per sample, and their abundances increased following effluent discharge from wastewater treatment plants. The river and wastewater samples were categorized based on their HT-qPCR profiles, indicating that this method was useful for characterizing the pollution status in aquatic environments. The prevalence of intI1 in the rivers was observed. Some ARGs and MGEs were positively correlated with intI1, indicating that intI1 could be used as a proxy for monitoring these ARGs and MGEs in urban rivers. Long-read sequencing of class 1 integron gene cassettes revealed that one to three ARGs were present in the gene cassettes. Regardless of the sample type, blaGES-24, aadA2, and qacH were dominant in the gene cassettes. The source and spread of class 1 integrons carrying these ARGs in aquatic environments should be further monitored.

https://www.frontiersin.org/articles/10.3389/fenvs.2022.825372/full