Abstract：
In recent years, large quantities of pharmaceuticals and personal care products (PPCPs) have been discharged into sewers, while the mechanisms of PPCPs enrichment in sewer sediments have rarely been revealed. In this study, three PPCPs (tetracycline, sulfamethoxazole, and triclocarban) were added consecutively over a 90-day experimental period to reveal the mechanisms of PPCPs enrichment and the transmission of resistance genes in sewer sediments. The results showed that tetracycline (TC) and triclocarban (TCC) have higher adsorption concentration in sediments compared to sulfamethoxazole (SMX). The absolute abundance of Tets and suls genes increased in sediments under PPCPs pressure. The increase in secretion of extracellular polymeric substances (EPS) and the loosening of the structure exposed a large number of hydrophobic functional groups, which promoted the adsorption of PPCPs. The absolute abundance of antibiotic resistance genes (ARGs), EPS and the content of PPCPs in sediments exhibited significant correlations. The enrichment of PPCPs in sediments was attributed to the accumulation of EPS, which led to the proliferation of ARGs. These findings contributed to further understanding of the fate of PPCPs in sewer sediments and opened a new perspective for consideration of controlling the proliferation of resistance genes.
摘要：
近年来,大量药品和个人护理产品(PPCPs)已排入下水道，而下水道沉积物中PPCPs富集的机制却很少被揭示。在这项研究中,三种PPCP(四环素，磺胺甲恶唑,在90天的实验期内连续添加三氯卡班），以揭示下水道沉积物中PPCPs富集和抗性基因传播的机制。结果表明，与磺胺甲恶唑（SMX）相比，四环素（TC）和三氯卡班（TCC）在沉积物中具有更高的吸附浓度。在PPCPs压力下，沉积物中Tets和suls基因的绝对丰度增加。胞外聚合物(EPS)分泌的增加和结构的松动暴露了大量的疏水官能团,促进了PPCPs的吸附。抗生素抗性基因(ARGs)的绝对丰度，沉积物中EPS与PPCPs含量呈显著相关关系。PPCPs在沉积物中的富集归因于EPS的积累，这导致了ARGs的扩散。这些发现有助于进一步了解下水道沉积物中PPCPs的命运，并为考虑控制抗性基因的增殖开辟了新的视角。
