摘要

       新兴的污染物抗生素耐药基因（ARGs）在河口等水环境中普遍存在。海岸红树林生态系统一直是天然湿地，接受的污水总是携带arg。目前，考虑ARG在红树林生态系统中分布的研究越来越受到重视。本文研究了南海红树林和非红树林区城市河口的ARGs多样性。共发现163个ARGs，分为22种抗性类型和6种抗性机制。河口样品的ARG丰度在0.144～0.203之间。这是在中国河口的一般范围内。差异分析表明，总ARGs、6种最丰富的ARGs（mtrA、rpoB、rpoC、rpsL、ef-Tu和parY）、最丰富的耐药类型（elfamycin、多药和肽）的丰度为0，红树林底泥中最丰富的抗性机制（目标改变）明显低于非红树林底泥（p<0.05）。网络分析和部分冗余分析表明，沉积物性质和移动遗传因子是影响ARG分布的最主要因素，而不是微生物群落。这两个因素共同解释了51.22%的精氨酸分布差异。我们的研究表明，红树林沉积物具有清除ARGs的能力。本研究为亚热带海洋红树林生态系统中ARG的发生和增殖提供了研究范式。

       The emerging pollutants antibiotic resistance genes (ARGs) are prevalent in aquatic environments such as estuary. Coastal mangrove ecosystems always serve as natural wetlands for receiving sewage which always carry ARGs. Currently, the research considering ARG distribution in mangrove ecosystems gains more interest. In this work, we investigated the diversity of ARGs in an urban estuary containing mangrove and nonmangrove areas of the South China Sea. A total of 163 ARGs that classified into 22 resistance types and six resistance mechanisms were found. ARG abundance of the samples in the estuary is between 0.144 and 0.203. This is within the general range of Chinese estuaries. The difference analysis showed that abundances of total ARGs, six most abundant ARGs (mtrA, rpoB, rpoC, rpsL, ef-Tu, and parY), the most abundant resistance types (elfamycin, multidrug, and peptide), and the most abundant resistance mechanism (target alteration) were significantly lower in mangrove sediment than that in nonmangrove sediment (p < 0.05). Network and partial redundancy analysis showed that sediment properties and mobile genetic elements were the most influential factors impacting ARG distribution rather than microbial community. The two factors collectively explain 51.22% of the differences of ARG distribution. Our study indicated that mangrove sediments have the capacity to remove ARGs. This work provides a research paradigm for analysis of ARG prevalence and proliferation in the subtropical marine coastal mangrove ecosystem.

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6855136/