PPCPs对饮用水生物滤池中ARGs传播的影响和机理研究

Antibiotic resistance genes (ARGs), as a new type of environmental pollutants, have become one of the major threats to global public health. At the same time, the pollution of pharmaceuticals and personal care products (PPCPs) in drinking water has also attracted widespread attention. The horizontal spread of ARGs is common in drinking water biological filters, and there are many factors affecting the spread of ARGs in biological filters. However, the influence and mechanism of PPCPs on the spread of ARGs in drinking water biological filters have not been well studied. Therefore, this project intends to screen the dominant resistant bacteria (ARB) from the strains isolated from drinking water treatment system, and to analyze the resistance genes and gene environment of the dominant ARB based on the date of whole genome sequence, which is in order to locate the resistance genes and evaluate the transferability of ARGs in ARB. In addition, a small-scale activated carbon water treatment device was constructed, the microbial community structure and the abundance and diversity of ARGs and mobile genetic elements (MEGs) in water treatment plant were studied by using metagenome and RT-PCR, which could reveal the effects and mechanisms of PPCPs on ARGs diffusion and transmission in biological filters, so as to understand the ecological toxicity of PPCPs more comprehensively and provide a theoretical basis for controlling the horizontal transmission of ARGs in drinking water biological filters.

抗生素抗性基因（ARGs）作为一种新型环境污染物，它的传播和扩散已成为全球公共健康的主要威胁之一。同时，药品及个人护肤品（PPCPs）在饮用水中的污染也受到广泛关注。饮用水生物滤池中ARGs水平传播普遍发生，影响生物滤池ARGs扩散和传播的因素纵多，而有关PPCPs对饮用水生物滤池中ARGs传播影响和机理尚缺乏研究。因此，本项目拟从前期饮用水菌种库中筛选出优势抗性菌（ARB），并基于全基因组序列分析优势ARB的抗性基因及基因环境，对抗性基因进行定位，评估ARB中ARGs可转移能力。构建小型活性炭水处理装置，采用宏基因组学，结合RT-PCR研究PPCPs对水处理装置中微生物群落结构、微生物ARGs和可移动遗传元件（MEGs）多样性和丰度变化，揭示PPCPs对生物滤池中ARGs扩散和传播的影响和机制，为更加全面地认识PPCPs生态毒性，遏制饮用水生物滤池中ARGs水平传播提供理论基础。

抗生素抗性基因（ARGs）作为一种新型环境污染物，它的传播和扩散已成为全球公共健康的主要威胁之一。同时，药品及个人护肤品（PPCPs）在饮用水中的污染也受到广泛关注。饮用水生物滤池中ARGs水平传播普遍发生，影响生物滤池ARGs扩散和传播的因素纵多，而有关PPCPs对饮用水生物滤池中ARGs传播影响和机理尚缺乏研究。因此，本项目采用宏基因组学全面解析了华南地区饮用水处理系统中抗生素抗性基因、抗生素抗性基因携带菌以及可移动遗传元件的分布特征，结果显示饮用水处理系统中共检测到13类ARGs， 其中丰度最高的是杆菌肽类、多重耐药类和磺胺类抗性基因。ARGs主要携带菌包括Acidovorax（6.0%）、Polynucleobacter（4.3%）、Pseudomonas（3.4%）、Stenotrophomonas （3.2%）和Escherichia（1.7%）。结合药敏纸片扩散法的实验结果，确定了饮用水系统中的优势耐药菌为Stenotrophomonas maltophilia F2 和 Pseudomonas aeruginosa B3。在此基础上，采用下一代测序技术对优势耐药菌进行了全基因组测序，进一步分析了耐药特征。同时考察了抗生素磺胺甲恶唑（SMX）对质粒RP4在同属和不同属菌株之间接合转移频率，以及对优势耐药菌的抗生素敏感性和生物膜的影响。另外，从宏观的角度出发，构建了饮用水小型处理装置，采用宏基因组学研究了SMX对活性炭柱中微生物群落结构及ARGs组成的影响。结果表明SMX在一定浓度范围内对ARGs的水平转移有促进作用，并对饮用水处理系统生物滤池中的ARGs分布和丰度有显著影响。通过本项目的研究，对我们进一步挖掘PPCPs对饮用水处理系统中微生物抗性影响机制打下了坚实的理论基础，对我们更全面地评估饮用水中PPCPs的生态毒性及健康风险提供了有力证据。