摘要

    在水环境中传播抗生素抗性基因（ARG）已成为越来越多的关注。关于地表水中ARGs的报道很多，但对于地下水中ARGs知之甚少。在这项研究中，我们使用高通量定量PCR（HT-qPCR）研究了与毛州河地表水相比，地下水中ARGs的分布和丰度。 HT-qPCR共检测到127个ARG和10个MGE，其中磺酰胺类，多药类和氨基糖苷类耐药基因为主要的ARG类型。根据HT-qPCR的结果，在潮湿季节和干燥季节，通过qPCR对18种经常检测到的对6种抗生素具有抗性的ARG和3种MGE进行了定量。绝对丰度在雨季为1.23×105至8.89×106拷贝/ mL，在旱季为8.50×102至2.65×106拷贝/ mL，其中sul1和sul2是最丰富的ARGs。 ARGs和MGEs的绝对丰度在雨季和旱季之间没有显着差异，而旱季的ARGs多样性高于雨季（p <0.05）。在Mao州河的水和沉积物中分别检测到141和150个ARG。地下水，河水和沉积物中共有116个ARG，占所有检测基因的67.1％。冗余分析进一步表明，环境因素占ARG总变化的70.7％。大量共享的ARGs，丰富的总大肠菌群和地下水中大量废水的发现提供了明确的证据，说明人为活动对地下水有重大影响。

    Dissemination of antibiotic resistance genes (ARGs) in the water environment has become an increasing concern. There have been many reports on ARGs in surface water, but little is known about ARGs in groundwater. In this study, we investigated the profiles and abundance of ARGs in groundwater in comparison with those in surface water of Maozhou River using high-throughput quantitative PCR (HT-qPCR). Totally 127 ARGs and 10 MGEs were detected by HT-qPCR, and among them the sulfonamides, multidrug and aminoglycosides resistance genes were the dominant ARG types. According to the results of HT-qPCR, 18 frequently detected ARGs conferring resistance to 6 classes of antibiotics and 3 MGEs were further quantified by qPCR in the wet season and dry season. The absolute abundance ranged from 1.23 × 105 to 8.89 × 106 copies/mL in wet season and from 8.50 × 102 to 2.65 × 106 copies/mL in the dry season, with sul1 and sul2 being the most abundant ARGs. The absolute abundance of ARGs and MGEs has no significant difference between the wet season and dry season while the diversity of ARGs in the dry season was higher than that in the wet season (p < 0.05). Totally 141 and 150 ARGs were detected in the water and sediments of Maozhou River, respectively. A total of 116 ARGs were shared among the groundwater, river water, and sediment, which accounted for 67.1% of all detected genes. Redundancy analysis further demonstrated that the environmental factors contributed 70.7% of the total ARG variations. The findings of large shared ARGs, abundant Total Coliforms and large wastewater burden in the groundwater provide a clear evidence that anthropogenic activities had a significant impact on groundwater.

    https://www.sciencedirect.com/science/article/abs/pii/S004896972030485X