环丙沙星和铜复合污染下河流底质微生物群落与抗生素抗性基因的交互关系

选择环丙沙星(CFC)和铜(Cu)作为目标污染物,设计室内驯化试验,通过16S rRNA高通量测序、定量PCR等技术探究CFC和Cu复合污染下河流底质微生物群落与抗生素抗性基因(ARGs)间的交互关系。结果表明,CFC单一污染、Cu单一污染和复合污染试验组中ARGs丰度、微生物群落组成及功能存在显著差异；所有试验组的总ARGs相对丰度呈现随时间先增后减的变化趋势。共现网络分析表明, intI 1与3类ARGs和8个菌群相关,是ARGs和微生物群落之间的桥梁；所属变形菌门、酸杆菌门、厚壁菌门、拟杆菌门和绿弯菌门的细菌最有可能成为水环境中ARGs的潜在宿主。基于偏冗余分析发现,在MGEs、微生物群落和污染物等因素中微生物群落对ARGs丰度变化总解释率最高(49.77%)；路径分析表明,CFC和Cu主要通过微生物群落间接地影响ARGs的传播和扩散。

Interaction relationship between microbial communities and antibiotic resistance genes under ciprofloxacin and copper co-contamination in river sediments

In this study, the ciprofloxacin (CFC) and copper (Cu) were selected as the target pollutants, indoor culture experiments were designed, and the interaction relationship between microbial communities and antibiotic resistance genes (ARGs)under ciprofloxacin and copper co-contamination in river sediments was explored using high throughput 16S rRNA sequencing and quantitative PCR. The results showed that the ARGs abundance, microbial community composition and functions were significantly different among different experimental groups (CFC contamination, Cu contamination and co-contamination). The total relative abundance of ARGs of each sample showed an increasing trend first, and then it decreased at the end of culture experiment. Co-occurrence network analysis suggested that intI 1 was associated with 3 types of ARGs and 8 bacterial communities, regarded as a bridge between ARGs and microbial community. Meanwhile, the bacteria that belonged to Proteobacteria, Acidobacteria, Firmicutes, Bacteroidetes and Chloroflexi was considered as the potential ARGs hosts in the aquatic environment. Based on the partial redundancy analysis, the microbial community had the highest overall interpretation rate (49.77%) for the change of ARGs abundance among MGEs, microbial communities, pollutants and other factors. At last, the path analysis showed that CFC and Cu pollutants indirectly affect the spread and diffusion of ARGs mainly through microbial communities.