摘要

       土壤环境中抗生素抗性基因 (ARG) 和抗生素抗性细菌 (ARB) 的日益流行对公众健康构成严重威胁。本研究调查了不同年份粪肥改良蔬菜土壤中ARGs和移动遗传元件（MGEs）的多样性和丰度。共8个基因，包括4个四环素抗性基因：tetW、tetM、tetO和tetT；两个磺胺类抗性基因：sul1和sul2；和两个 MGE：intI1 和 intI2；在十种植物土壤中定量。施肥处理的土壤中ARGs的相对丰度显着高于未施肥的土壤。 intI1和intI2基因的相对丰度与tetW、tetO、sul1和sul2基因的相对丰度呈显着正相关。在不同抗生素浓度下，粪肥改良土壤的耐药菌率远高于对照土壤。在两种抗生素中均检测到芽孢杆菌和金黄色杆菌，它们更可能是多重耐药菌。此外，发现铜和锌的浓度与 ARG 之间存在显着相关性。我们的研究结果提供了经验证据，证明 ARGs 和 ARB 在长期粪肥改良的蔬菜土壤中的传播风险，这可能会促进制定有效策略以减少 ARGs 在农业生态系统中的传播。

       The increasing prevalence of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) in the soil environment represents a serious threat to public health. In this study, the diversity and abundance of ARGs and mobile genetic elements (MGEs) in different years of manure-amended vegetable soils were investigated. A total of eight genes, including four tetracycline resistance genes: tetW, tetM, tetO and tetT; two sulfonamide resistance genes: sul1 and sul2; and two MGEs: intI1 and intI2; were quantified in ten vegetable soils. The relative abundance of ARGs in soils amended with manure was significantly higher than that in soils without manure application. The relative abundance of the intI1 and intI2 genes had significantly positive correlations with the relative abundance of the tetW, tetO, sul1 and sul2 genes. Under different concentrations of antibiotics, the resistant bacteria rates of manure-amended soil were much higher than the control soil. Bacillus and Chryseobacterium, more likely to be multi-drug-resistant bacteria, were detected in both two antibiotics. Moreover, the significant correlation was found between the concentrations of Cu and Zn and the ARGs. Our findings provide empirical evidence that the dissemination risk of ARGs and ARB in long-term manure-amended vegetable soils, which might promote to the development of effective strategies to reduce the spread of ARGs in agro-ecosystems.

https://www.sciencedirect.com/science/article/abs/pii/S0048969718343468