【摘要】 抗生素抗性基因被认为是一种环境污染物,城市生活垃圾填埋场及其渗滤液中存在着多种类和高丰度的抗生素抗性基因.针对生活垃圾渗滤液处理工艺流程特点,本研究采用超高通量定量PCR技术,分析生活垃圾渗滤液处理过程中抗生素抗性基因的变化特征.结果表明,渗滤液处理使得出水抗生素抗性基因丰度减至9. 2×1010copies·L-1,降低了5个数量级,能有效消减渗滤液中的抗生素抗性基因,是一种有效消减垃圾渗滤液抗生素抗性基因丰度的方法;渗滤液出水中的抗生素抗性基因140种,检出率高达46. 7%,相较于自然环境,出水中抗生素抗性基因种类和丰度仍然维持在较高水平,直接排入市政污水管网可能造成抗生素抗性基因的二次扩散,存在着较高的生态环境风险;渗滤液中抗生素抗性基因与Cr、Cd、Ni、As、MGEs、integron和transposon呈现极显著的正相关关系,表明抗生素抗性基因的赋存和迁移传播可能受重金属元素和可移动遗传元件的共同影响.更多还原

【Abstract】 Antibiotic resistance genes( ARGs) are considered to be emerging environmental contaminants. ARGs are frequently detected in municipal solid waste landfill and its leachate. In this study,high-throughput quantitative PCR techniques were used to investigate the dynamics of ARGs during the treatment process of landfill leachate. The results showed that ARGs in leachate were diverse and abundant,and leachate treatment could effectively reduce their abundance; the absolute abundance of ARGs was reduced to 9. 2 × 1010 copies·L-1,which was five orders of magnitude less than the abundance of the influent. However,the range and abundance of antibiotic resistance genes in the leachate effluents were still high compared to the natural environment. Therefore,the secondary contamination of ARGs might be caused by leachate being directly discharged into municipal sewage system. In this regard,ecological and environmental risk is an inconvenient truth. Furthermore,strong correlations indicate that heavy metals and mobile genetic elements( MGEs) in landfill leachate might influence the transfer of ARGs.更多还原