尾矿库水体环境抗生素抗性基因的分布特征

Diversity and Abundance of Antibiotic Resistance Genes in Tailings Ponds

抗生素抗性基因是近年来人们普遍关注的新型环境生物污染物,也是科学家们研究的热点.为了探究尾矿库水体环境抗生素抗性基因的污染特征,揭示尾矿库水体环境抗生素抗性基因的影响因素,本文采用超高通量定量PCR技术(HT-q PCR),研究了某尾矿库的4个点位的水体抗生素抗性基因的多样性、丰度和驱动机制.结果表明,尾矿库水体环境具有种类多样的抗生素抗性基因,库区水体(WK0)、主坝排渗水(WK1)、副坝排渗水(WK2)和河水(HS)分别检测出抗生素抗性基因97、52、44和56种,可移动遗传元件分别检测到11、6、3和6种;在绝对丰度水平上,库区水体(WK0)、主坝排渗水(WK1)、副坝排渗水(WK2)和河水(HS)分别有1.75×10^(8)、6.39×10^(7)、9.90×10^(7)和7.37×10^(7)copies·L^(-1),库区水体的抗性基因丰度最高,表明库区是一个潜在的抗性基因存储库;冗余分析(RDA)表明,铜Cu、总有机碳TOC和可移动遗传元件(MGEs)与抗生素抗性基因呈显著正相关的关系,这3个因素对抗生素抗性基因变化的解释量达到了61.64%(前两轴),因此Cu、TOC和MGEs对尾矿库水体环境抗生素抗性基因的赋存和演变可能具有重要作用.

Antibiotic resistance genes(ARGs)are considered emerging contaminants posing an increasing threat to the ecological environment and global human health.Profiling ARGs in tailings ponds is essential to better understand their spatial and temporal dynamics.In this study,high-throughput quantitative polymerase chain reaction(PCR)techniques were used to investigate the occurrence,diversity,abundance,and distribution of ARGs in a tailings pond.A total of 97,52,44,and 56 ARGs were detected in WK0,WK1,WK2,and HS,respectively,with 11,6,3,and 6 mobile genetic elements(MGEs)also being detected,respectively.The absolute abundance of ARGs in the pond water ranged from 6.39×10^(7) to 1.75×10^(8)copies·L^(-1).Additionally,the abundance of MGEs were higher than ARGs in WK1 and WK2,indicating the potential for horizontal gene transfer(HGT).Furthermore,Cu,TOC,and MGEs were significantly associated with ARGs.Indeed,redundancy analysis(RDA)revealed that Cu,TOC,and MGEs explained 61.64%of the alteration of the ARG profiles,implying their potential roles in the spread and evolution of ARGs in tailings ponds.