摘要
      经处理的废水灌溉（TWW）将抗生素和抗生素抗性基因（ARGs）释放到环境中，从而可能促进抗生素抗性在地下水（GW）中的传播。我们假设TWW灌溉通过两种潜在机制增加了GW中ARG的丰度：GW被耐药细菌污染和GW中抗生素的积累。为了测试这一点，对实际规模TWW灌溉田以下的GW进行了六个月的采样。采样在高强度TWW灌溉之前、期间和之后进行。用16S rRNA扩增子测序、6个ARG的qPCR和1类整合子整合酶基因intI1分析样品，同时用液相色谱-串联质谱法检测抗生素和药物残留。在长期灌溉期间，GW中16S rRNA的绝对丰度降低而不是增加。此外，在长期灌溉期间，GW中TWW相关细菌的相对丰度没有增加。相反，长期TWW灌溉增加了GW微生物组中sul1和intI1的相对丰度。此外，GW含有浓度升高的磺酰胺类抗生素，尤其是磺胺甲恶唑，sul1会对其产生耐药性。GW中的总磺酰胺浓度与sul1的相对丰度相关。因此，TWW灌溉促进了sul1和intI1在GW微生物组中的传播，很可能是由于药物残留的积累。
Abstract
Treated wastewater irrigation (TWW) releases antibiotics and antibiotic resistance genes (ARGs) into the environment and might thus promote the dissemination of antibiotic resistance in groundwater (GW). We hypothesized that TWW irrigation increases ARG abundance in GW through two potential mechanisms: the contamination of GW with resistant bacteria and the accumulation of antibiotics in GW. To test this, the GW below a real-scale TWW-irrigated field was sampled for six months. Sampling took place before, during and after high-intensity TWW irrigation. Samples were analysed with 16S rRNA amplicon sequencing, qPCR of six ARGs and the class 1 integron-integrase gene intI1, while liquid chromatography tandem mass spectrometry was performed to detect antibiotic and pharmaceutical residues. Absolute abundance of 16S rRNA in GW decreased rather than increased during long-term irrigation. Also, the relative abundance of TWW-related bacteria did not increase in GW during long-term irrigation. In contrast, long-term TWW irrigation increased the relative abundance of sul1 and intI1 in the GW microbiome. Furthermore, GW contained elevated concentrations of sulfonamide antibiotics, especially sulfamethoxazole, to which sul1 confers resistance. Total sulfonamide concentrations in GW correlated with sul1 relative abundance. Consequently, TWW irrigation promoted sul1 and intI1 dissemination in the GW microbiome, most likely due to the accumulation of drug residues.

https://www.sciencedirect.com/science/article/pii/S0304389421021233