| 东洞庭湖表层水体中抗生素及抗性基因的赋存特征与源分析 |
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| 引用本文： | 宋冉冉,国晓春,卢少勇,刘晓晖,王晓慧.东洞庭湖表层水体中抗生素及抗性基因的赋存特征与源分析[J].环境科学研究,2021,34(9):2143-2153. |
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| 作者姓名： | 宋冉冉 国晓春 卢少勇 刘晓晖 王晓慧 |
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| 作者单位： | 1.北京化工大学化学工程学院, 北京 100029 |
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| 基金项目： | 国家自然科学基金项目41877409 |
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| 摘 要： | 抗生素抗性基因（ARGs）是一类新兴污染物，广泛存在于多种环境介质中.湖泊水环境由于污染物循环速度低而可以长期储存ARGs.因此，ARGs领域的研究人员非常关注湖泊水环境的研究.然而，以往的研究多集中于湖泊内ARGs的污染水平，污染来源仍不确定.东洞庭湖是国家级自然保护区，在保护生态环境和调节长江洪水径流方面发挥着重要作用.为了探究东洞庭湖表层水体中抗生素及ARGs的赋存特征、分析ARGs与环境参数（如抗生素）之间的相关性以及了解陆地污染源对湖内ARGs的贡献，于2019年11月采集东洞庭湖表层水和陆地污染源（水产养殖区和污水处理厂）样品，利用超高效液相色谱串联质谱仪和荧光定量PCR技术分别检测抗生素和ARGs，同时测定水质参数并进行冗余分析.结果表明:①东洞庭湖表层水体中抗生素浓度水平处于ND（未检出）~486.59 ng/L，氧氟沙星浓度最高，且抗生素的浓度水平与周边污染源密切相关.②ARGs检出率均为100%，基因sul2的浓度高于其他基因，平均浓度为1.3×103 copies/mL，ARGs污染水平受到沿湖污染源的影响.③污水处理厂对ARGs具有一定的去除效果，然而，它们不能完全去除ARGs，甚至可能会增加ARGs传播的可能性，且污水处理厂出水ARGs对湖内ARGs的贡献远高于水产养殖区.④ARGs与抗生素的冗余分析结果符合ARGs在其对应抗生素选择性压力下的特征，对ARGs丰度影响最重要的4个水质参数分别为总磷（贡献率为28.9%）、电导率（贡献率为15.4%）、硝酸盐氮（贡献率为13.3%）和温度（贡献率为12.7%）.研究显示，氧氟沙星和罗红霉素是主要抗生素，磺胺类和四环素类抗性基因浓度水平较高，ARGs的丰度不仅与其对应抗生素的选择性压力有关，还与一些环境因素的压力密切相关.
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| 关 键 词： | 东洞庭湖 抗生素抗性基因(ARGs) 赋存 源分析 冗余分析 |
| 收稿时间： | 2021-01-21 |
Occurrence and Source Analysis of Antibiotics and Antibiotic Resistance Genes in Surface Water of East Dongting Lake Basin |
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| Affiliation: | 1.College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China2.State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing 100012, China |
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| Abstract: | Antibiotic resistance genes (ARGs) are emerging pollutants, which is widely present in a variety of environmental media. The lake water can sustain ARGs for a long time due to the low circulation rate of pollutants. Hence, researchers in the ARGs field pay much attention to lake water studies. However, previous studies mainly focused on the pollution level of ARGs in lakes, and the sources of pollution remain uncertain. East Dongting Lake is a National Nature Reserve, which plays an important role in protecting the ecological environment and mitigating the floods in Yangtze River. Samples of surface water and land pollution sources (aquaculture areas and sewage treatment plants) of East Dongting Lake were collected in November 2019 to explore the occurrence characteristics of antibiotics and ARGs in the surface water of East Dongting Lake, analyze the correlation between ARGs and environmental parameters (e.g., antibiotics), and understand the contribution of land pollution sources to ARGs in the lake. Antibiotics and ARGs were detected by using ultra performance liquid chromatography tandem mass spectrometry and fluorescence quantitative PCR, respectively. Meanwhile, water quality parameters were calibrated and redundancy analysis was carried out. The results showed that: (1) The concentration of antibiotics in the surface water of East Dongting Lake was in the range of ND (Non-Detected)-486.59 ng/L, and ofloxacin concentration was the highest. The spatial distribution analysis showed that the concentration of antibiotics was closely related to the surrounding pollution sources. (2) The detection rate of ARGs was 100%, and the concentration of sul2 was higher than others, with an average concentration of 1.3×103 copies/mL. In addition, the spatial distribution also showed that the pollution levels of ARGs was affected by pollution sources along the lake. (3) Sewage treatment plants can reduce ARGs to a certain extent, but cannot completely remove ARGs, and may even increase the possibility of ARGs transmission. Furthermore, the contribution of wastewater treatment plants to the ARGs of the lake is much higher than that of aquaculture areas. (4) The results of redundancy analysis between ARGs and antibiotics were consistent with the characteristics of ARGs under the selective pressure of their corresponding antibiotics. Total phosphorus (contribution rate was 28.9%), conductivity (contribution rate was 15.4%), nitrate nitrogen (contribution rate was 13.3%) and temperature (contribution rate was 12.7%) were the four most important water quality parameters affecting ARGs abundance. The results showed that ofloxacin and roxithromycin were the main antibiotics in terms of concentration, and the concentration of sulfonamides and tetracyclines resistance genes was high. The abundance of ARGs was not only related to the selective pressure of the corresponding antibiotics, but also to the pressure of some environmental factors. |
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