摘要

药性基因（ARGs）在水环境中的传播已成为人们日益关注的问题。关于地表水中ARGs的报道很多，但对地下水中ARGs的研究却很少。本研究采用高通量定量PCR（HT qPCR）技术，对茂州河（Maozhou River）地下水中ARGs的简况和丰度进行了研究。HT-qPCR共检测到127个ARGs和10个MGEs，其中以磺胺类、多重耐药和氨基糖苷类耐药基因为主。根据HT qPCR结果，在旱季和雨季，应用qPCR进一步定量了18种常见的6类抗生素耐药ARGs和3种MGEs。ARGs的绝对丰度在雨季为1.23×105~8.89×106拷贝/mL，旱季为8.50×102~2.65×106拷贝/mL，其中以sul1和sul2最为丰富。旱季和丰水期ARGs和MGEs绝对丰度差异不显著，而旱季ARGs多样性高于丰水期（p<0.05）。在茂州河水体和沉积物中分别检测到141个和150个arg。总共116个ARGs在地下水、河水和沉积物共有，占所有检测基因的67.1%。冗余度分析进一步表明，环境因子对ARG变异的贡献率为70.7%。地下水中发现大量共有的ARGs、丰富的大肠菌群以及巨大的废水负荷的研究结果为人类活动对地下水的影响提供了明确的证据。

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/pii/S004896972030485X