摘要
      抗生素的不合理使用和抗生素诱导的抗生素抗性基因（ARGs）的传播，导致大量ARGs进入水环境，严重威胁人类健康和环境安全。河口水生环境与内河和海洋相连，经常受到人类活动的影响。本研究旨在通过包括296个引物的高通量定量PCR和高通量测序，揭示中国永江口地表水起潮和退潮过程中ARGs的出现和丰度以及细菌群落组成。结果表明，在涨潮和退潮水体中检测到大量的ARGs和可移动遗传元素（MGE）。在涨潮和退潮时，每个样本中检测到的ARGs数量分别为16至77和61至88，绝对丰度范围分别为1.69×104–1.69×109拷贝/L和3.18×103–2.57×109拷贝g/L。ARGs具有明显的潮汐分布特征。大多数ARGs对多药、氨基糖苷类和磺胺类药物具有耐药性。变形菌门、放线菌门和拟杆菌门是甬江口的主要细菌门。网络分析结果表明，多个属被鉴定为可能的ARGs宿主，它们携带两种以上的ARG基因。偏最小二乘路径模型进一步揭示了MGE和细菌群落组成是最重要的驱动因素。研究结果可以为ARGs在河口的扩散和控制提供相应的科学依据。
Abstract
The unreasonable use of antibiotics and the transmission of antibiotic resistance genes (ARGs) induced by antibiotics have led to a large number of ARGs entered the water environment, which seriously threatened human health and environmental safety. The estuarine aquatic environment connects with inland rivers and sea and is frequently influenced by human activities. This study aims to reveal the occurrences and abundances of ARGs and bacterial community composition by high-throughput quantitative PCR including 296 primers and high-throughput sequencing in the tide rising and ebbing of surface water in the Yongjiang Estuary, China. The results showed that there were a large number of ARGs and mobile genetic elements (MGEs) detected in the rising tide and ebb tide water bodies. The numbers of detected ARGs in each sample at rising and ebb tide ranged from 16 to 77 and 61 to 88, respectively, and the absolute abundance ranges were 1.69 × 104–1.69 × 109 copies/L and 3.18 × 103–2.57 × 109 copies/L, respectively. Obvious tidal distribution characteristics of ARGs were showed. Most of ARGs conferred resistance to multidrug, aminoglycosides and sulfanilamides. Proteobacteria, Actinobacteria and Bacteroidetes were the dominantly bacterial phylum in the Yongjiang Estuary. Network analysis results indicated that multi-genera were identified as possible ARGs hosts, and they carried more than two types of ARGs genes. Partial least squares path modeling further revealed that MGEs and bacterial community composition were the most important driving factors. The results of the study can provide the corresponding scientific basis for the diffusion and control of ARGs in estuaries.

https://www.sciencedirect.com/science/article/abs/pii/S0013935122009768