摘要

      抗生素和微量元素的大规模使用导致它们在环境中的不断释放，最终导致抗生素耐药基因（ARGs）和金属离子耐药基因（MRGs）在细菌中的传播。对含有抗性基因的恒河水体和沉积物中的微生物群落进行了高通量的宏基因组测序。结果表明，该河底泥中含有丰富的抗病基因。高显性ARGs类型为β-内酰胺、多药/外排和elfamycin。泥质（tuf、parY、ileS、mfd）在水体和沉积物中含量丰富。MRGs亚型acn是水体和沉积物中最丰富的金属抗性基因。多数ARGs类型与河流环境中的MRGs类型呈显著正相关（p<0.05），表明它们的分布和迁移可能有联系。分类结果表明，蛋白质细菌和放线菌是水体和沉积物中最丰富的两个门。弧菌属、地杆菌属、酸杆菌属和假单胞菌属最为丰富。这项研究表明，抗生素和金属是产生耐药基因的驱动力，它们随后在环境细菌中繁殖和积累。目前的宏基因组研究突出了这类研究的意义，并引起了人们对减少与ARGs和MRGs在河流环境中传播有关的污染物的关注。

       The large scale usage of antibiotics and trace elements leads to their progressive release in the environment, and ultimately the spread of antibiotic resistance genes (ARGs) and metal ion resistance genes (MRGs) in bacteria. A high-throughput metagenomic sequencing of the microbial community in water and sediments in the river Ganges harboring resistance genes was performed. The results revealed that the river harbors a broad spectrum of resistance genes with high abundance in sediments. The highly dominant ARGs type was beta-lactam, multidrug/efflux and elfamycin. The ARGs such as (tuf, parY, ileS, mfd) were highly abundant in water and sediments. The MRGs subtype acn was the most abundant metal resistance gene in water and sediments. Majority of ARGs types showed significant (p ≤ 0.05) positive correlation with the MRGs types in the river environment suggesting their distribution and transfer to be possibly linked. Taxonomic classification revealed that Proteobacteria and Actinobacteria were the two most abundant phyla in water and sediments. Arcobacter, Terrimicrobium, Acidibacter and Pseudomonas were the most abundant genera. This study suggests that antibiotics and metals are the driving force for the emergence of resistance genes, and their subsequent propagation and accumulation in the environmental bacteria. The present metagenomic investigation highlights significance of such study, and attracts attention for the mitigation of pollutants associated with the propagation of ARGs and MRGs in the river environment.

       https://www.sciencedirect.com/science/article/pii/S0269749118342969?via%3Dihub