Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Sci Total Environ. 2018 Jan 15;612:1-8. doi: 10.1016/j.scitotenv.2017.08.072. Epub 2017 Sep 1.
The contamination of antibiotic resistance genes (ARGs) in drinking water may pose a direct threat to human health. This study applied high-throughput qPCR and sequencing to investigate the dynamics of ARGs and bacterial communities during the advanced treatment of drinking water using biological activated carbon. The promotion of ARGs was observed, and the normalized copy number of ARGs increased significantly after BAC treatment, raising the number of detected ARGs from 84 to 159. Twenty-nine ARGs were identified as biofilm-influencing sources in the BAC, and they persisted after chlorination. The shift of bacterial communities primarily had effects on the changes in resistome. Firmicutes, Cyanobacteria were related to persistent ARGs mostly in the BAC biofilm. Meanwhile, the Acyl-Homoserine Lactones (AHLs), quorum sensing molecules, and bacteria that produced AHLs were identified to understand the promotion of ARGs. The isolated AHL-producing bacteria belonged to the Proteobacteria, Firmicutes and Bacteroidetes phyla. Six detectable AHLs had an influence on plasmid-based horizontal gene transfer in the intragenus mating systems, indicating that the dynamics of ARGs were strongly affected by quorum sensing between specific bacteria in the biofilm. These results provide new insight into the mechanism of antibiotic resistome promotion in BAC biofilms.
抗生素耐药基因（ARGs）在饮用水中的污染可能直接威胁到人类健康。本研究应用高通量 qPCR 和测序技术，研究了生物活性炭深度处理饮用水过程中 ARGs 和细菌群落的动态变化。研究发现，生物活性炭处理后 ARGs 得到了促进，ARGs 的归一化拷贝数显著增加，检测到的 ARGs 数量从 84 个增加到 159 个。在生物活性炭中发现了 29 个与生物膜有关的 ARGs，它们在氯化后仍然存在。细菌群落的变化主要影响了耐药组的变化。厚壁菌门和蓝细菌与生物活性炭中持久性 ARGs 关系最为密切。同时，鉴定出酰基高丝氨酸内酯（AHLs）、群体感应分子和产生 AHLs 的细菌，以了解 ARGs 的促进作用。分离出的产生 AHLs 的细菌属于变形菌门、厚壁菌门和拟杆菌门。六种可检测到的 AHLs 对种内交配系统中的质粒水平基因转移有影响，表明生物膜中特定细菌之间的群体感应强烈影响了 ARGs 的动态变化。这些结果为生物活性炭生物膜中抗生素耐药组促进机制提供了新的见解。
