摘要

    农田土壤中广泛存在微塑料（MPs）和抗生素抗性基因（ARGs），但很少探索MPs上ARGs的去向和丰度。在这项研究中，高通量荧光定量聚合酶链反应用于确定设施蔬菜土壤中MP的ARGs。结果表明，当MPs的粒径较大时，风化更为严重，或者MPs来自蔬菜栽培期长的土壤，MPs上的抗生素和重金属含量较高。在不同的MP上检测到的ARGs类型的分布显示出变化。与弱风化的MPs相比，强风化的MPs上检测到的β-内酰胺酶和氨基糖苷抗性基因分别降低了2.6％和1.7％，而sul-ARGs和大环内酯-林可酰胺-链霉菌素B（MLSB）的抗性基因增加了1.5％。和2.8％。与较小的MP相比，在较大的MP上检测到的MLSB和万古霉素抗性基因分别降低了2.0％和1.4％，而检测到的氟喹诺酮，喹诺酮，氟苯尼考，氯霉素和苯酚（FCA）耐药基因和sul-ARGs增加了1.2 ％和1.0％。与蔬菜种植三年后的土壤MPs相比，蔬菜种植十年后土壤中MPS的检测到的FCA抗性基因和sul-ARGs分别降低了1.3％和1.6％，而检测到的β-内酰胺酶和氨基糖苷抗性基因分别为分别增长了1.0％和1.7％。这项研究表明，具有较大尺寸，耐候性强或经过长期蔬菜种植的土壤中的MPs吸收更多的抗生素和重金属，并引起更多的移动遗传元素，这可能对MPs产生抗药性。 

    Microplastics (MPs) and antibiotic resistance genes (ARGs) coexist widely in farmland soils, but the fate and abundance of ARGs on MPs is rarely explored. In this study, high-throughput fluorescent quantitative polymerase chain reaction was used to determine ARGs on MPs in facility vegetable soil. The results indicated that when the particle size of the MPs was larger, the weathering was more serious, or the MPs came from soils with a long vegetable cultivation period, the levels of antibiotics and heavy metals on the MPs were higher. The distribution of the detected ARGs types on distinct MPs showed changes. Compared with weakly weathered MPs, the detected beta lactamase and aminoglycoside resistance genes on strongly weathered MPs were decreased by 2.6% and 1.7%, while the detected sul-ARGs and Macrolide-Lincosamide-Streptogramin B (MLSB) resistance genes were increased by 1.5% and 2.8%. Compared with smaller MPs, the detected MLSB and vancomycin resistance genes on larger MPs were decreased by 2.0% and 1.4%, while the detected fluoroquinolone, quinolone, florfenicol, chloramphenicol, and amphenicol (FCA) resistance genes and sul-ARGs were increased by 1.2% and 1.0%. Compared with MPs in soil after three years of vegetable cultivation, the detected FCA resistance genes and sul-ARGs on MPs in soil after ten years of vegetable cultivation were decreased by 1.3% and 1.6%, while the detected beta lactamase and aminoglycoside resistance genes were increased by 1.0% and 1.7%. This study suggests that MPs with larger size, stronger weathering or from soil after long-term vegetable cultivation adsorb more antibiotics and heavy metals and cause more mobile genetic elements, which can contribute to antibiotic resistance on the MPs.

    https://www.sciencedirect.com/science/article/abs/pii/S0048969719362722