城市生活污水中抗菌剂与抗生素抗性基因的污染特征及其关联性研究

Antibiotic resistance genes (ARGs) in the environment could spread among various mediums via horizontal gene transfer, leading to immeasurable risks to the public health and ecological stability. Researches show that the widespread use of antimicrobial chemicals could cause certain selection pressures on the spread of ARGs. While previous studies mainly focused on the residues of antibiotics and diversities of ARGs, the relationship between antimicrobial chemicals on the municipal wastewater microbiome and ARGs have not been examined. The objective of this project is to investigate the relationship between the concentration of antimicrobial chemicals and the abundance of ARGs in municipal wastewater. Samples are subdivided for chemical and DNA extraction and examined using liquid chromatography tandem mass spectrometry (LC-MS/MS) and metagenome sequencing. All data set are processed using various statistical analyses to explore the relationships between the antimicrobial chemicals on the municipal wastewater microbiome and ARGs. Further test will be done using microcosms to study the mechanism of how the typical antimicrobial chemicals influence the abundance of ARGs. This project will provide data support for reducing the contamination of ARGs in municipal wastewater, and offer scientific basis for the control of ARGs spreading in the natural environment.

抗生素抗性基因（ARGs）可通过水平转移在环境中迁移传播，给生态安全和人类健康带来隐患。研究表明，抗菌剂类物质对ARGs的传播存在一定的选择压力。然而以往的研究多集中在抗生素的环境残留与ARGs的污染水平及多样性方面，尚缺少抗菌剂类物质对ARGs污染变化的影响研究。本项目拟以城市生活污水为研究对象，开展抗菌剂与ARGs的污染特征及关联性研究。利用液相质谱联用技术和宏基因组测序技术，考察抗菌剂及ARGs在城市生活污水中的污染变化规律，通过分析水体中微生物群落结构的变化特征，综合运用多种统计学分析方法，揭示抗菌剂与ARGs污染变化及微生物群落结构变化的关联性。进一步利用微宇宙培养实验研究验证典型抗菌剂与ARGs及微生物群落结构变化的相互关系，阐明抗菌剂在ARGs传播扩散过程中的影响机制。研究结果为降低城市生活污水中ARGs污染提供数据支持，为进一步控制ARGs的传播扩散提供科学依据。

目前，关于环境中高浓度的抗菌剂与大多数种类的抗性基因及微生物群落结构变化的研究较少。在本研究中，我们研究了抗菌剂与抗生素抗性基因及微生物群落结构变化的相互关系。城市污水处理厂中的环境样品（进出水和回流污泥）使用宏基因组测序技术和液质联用技术进行分析测定。每个样品的宏基因组数据中抗生素抗性基因的筛选使用综合性抗生素耐药性数据库。三种丰度最高的抗性基因分别为adeF、sul1和qacEdelta1，抗菌剂中MePB浓度最高在进出水样品中浓度高达876 ng/L。我们发现6种显著性的正相关关系存在于抗菌剂浓度变化和抗生素抗性基因相对丰度之间。微宇宙实验证明TCC与tetX之间存在显著相关关系。本研究首次分析生活污水中抗菌剂与抗性基因的相关关系，研究结果为进一步控制抗性基因在自然环境中的增殖和传播提供数据支持。