摘要

       微塑料（MPs）和抗生素抗性基因（ARGs）在农田土壤中广泛共存，但很少探索微塑料（MPs）和抗生素抗性基因（ARGs）在MPs上的命运和丰度。在这项研究中，高通量荧光定量聚合酶链反应用于测定设施蔬菜土壤中 MPs 上的 ARGs。结果表明，当 MPs 的粒径越大，风化越严重，或 MPs 来自蔬菜栽培时间长的土壤时，MPs 上的抗生素和重金属含量越高。不同 MP 上检测到的 ARG 类型的分布显示出变化。与弱风化MPs相比，在强风化MPs上检测到的β-内酰胺酶和氨基糖苷类抗性基因分别降低了2.6%和1.7%，而检测到的sul-ARGs和大环内酯-林可酰胺-链霉菌素B（MLSB）抗性基因增加了1.5%和 2.8%。与较小的MPs相比，较大MPs上检测到的MLSB和万古霉素耐药基因分别降低了2.0%和1.4%，而检测到的氟喹诺酮类、喹诺酮类、氟苯尼考、氯霉素和氨酚（FCA）耐药基因和sul-ARGs增加了1.2 % 和 1.0%。与蔬菜种植三年后土壤中的MPs相比，蔬菜种植十年后土壤MPs上检测到的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类抗性基因则下降了分别增加了 1.0% 和 1.7%。该研究表明，体积较大、风化能力较强或长期蔬菜种植后来自土壤的 MP 吸附更多的抗生素和重金属，并产生更多的移动遗传元件，这可能有助于 MP 的抗生素抗性。

       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