摘要

      河流系统通常被认为是抗生素耐药基因（ARGs）的自然库，更容易受到人为活动的影响。本研究于2017年3月和7月对西安市巴河流域7类14种抗生素和23种相应的ARGs的发生、分布进行了调查。磺胺类药物、喹诺酮类药物、大环内酯类药物和四环素类药物的检出率在85.7%-100%之间。在水样（高达8.54 × 102 ng L-1）和沉积物样品（高达2.08   103 μg kg-1）中分别检测到高浓度的四环素。与3月份相比，7月份的抗生素总浓度要高得多。在绝对丰度方面，苏尔1、特塔、特克、特茨、吉拉、ermF、cmlA和blaTEM是优势ARGs。3月份的水沙样品与7月份相比，ARGs的相对丰度除sul3外均无显著差异。四环素类抗生素与tet基因呈正相关，其余抗生素与相应的ARGs无显著相关，提示环境因素和交叉选择可能对ARGs的分布有显著影响。通过冗余分析进一步预测环境因素对抗生素和ARGs丰度的影响。研究结果表明，人为活动对抗生素污染的持续性有显著贡献。

      The riverine system is usually considered as a natural reservoir of antibiotic resistance genes (ARGs) and more susceptible to anthropogenic activities. In this study, the occurrence and distribution of 14 antibiotics belonging to 7 categories together with 23 corresponding ARGs in Ba River of Xi'an China were investigated in March and July 2017. Sulfonamides, quinolones, macrolides and tetracyclines were detected in high frequencies ranged from 85.7% to 100%. Tetracyclines were detected with high concentrations in water samples (up to 8.54 × 10² ng L^-1) and sediment samples (up to 2.08 × 10³ μg kg^-1), respectively. The total concentrations of antibiotics were much higher in July in comparison with March. The sul1, tetA, tetC, tetZ, gyrA, ermF, cmlA and bla_TEM were the predominant ARGs in terms of absolute abundance. For both water and sediment samples in March compared with July, the relative abundance of ARGs had no significant difference except for sul3. The tetracyclines had positive correlation with tet genes, whereas the remaining antibiotics had no significant correlations with their corresponding ARGs, suggesting that environmental factors and cross-selection may significantly influenced the distribution of ARGs. Redundancy analysis was performed to further predict the influences of environmental factors on antibiotics and ARG abundance. The findings suggest that anthropogenic activities contribute significantly to the persistence of antibiotics pollution.

       https://linkinghub.elsevier.com/retrieve/pii/S0048-9697(18)32225-3