高垦殖丘陵区不同类型农用地土壤中抗生素抗性基因分布特征

Characteristics of Antibiotic Resistance Genes Distribution in Different Types of Agricultural Land Soils in Highly Cultivated Hilly Areas

为揭示高垦殖丘陵区不同类型农用地土壤中抗生素抗性基因分布特征,分析了抗生素抗性基因在菜地、果园和耕地土壤中的丰度和多样性.结果表明,所有土壤样品中共检出70种抗生素抗性基因和4种可移动基因元件,其中β-内酰胺类cphA-01抗性基因是农用地土壤中相对丰度最高的耐药基因.在菜地和果园土壤中,主要的抗性基因亚型为cphA-01和cmx(A),而耕地土壤以mexF和aacC基因为主.土壤中抗生素抗性基因的相对丰度和多样性均表现为:耕地<菜地<果园,这与不同农用地土壤的养分条件差异有关.类似地,土壤中可移动基因元件的相对丰度和多样性均以耕地土壤为最低,而其最高值分别出现在菜地和果园样品中.高垦殖丘陵区农用地土壤环境中可移动基因元件与抗生素抗性基因丰度呈显著正相关关系(P<0.05),表明基因水平迁移可能促进抗生素抗性基因在高垦殖丘陵区农用地土壤环境中扩散.

To characterize the distribution of antibiotic resistance genes(ARGs)in different types of agricultural soil in highly cultivated hilly areas,the abundance and diversity of ARGs in vegetable,orchard,and arable soils were analyzed in this study.The results showed that 70 ARGs and four mobile genetic elements(MGEs)were detected in all soil samples,with β-lactam cphA-01 being the most abundant genes in the agricultural soils.In vegetable and orchard soils,the main ARG subtypes were cphA-01 and cmx(A)genes,whereas the mexF and aacC genes were predominant in cropland soils.The relative abundance and diversity of soil ARGs showed that cropland<vegetable land<orchard,which was related to the nutrient conditions of different agricultural soils.Similarly,the relative abundance and diversity of MGEs were lowest in cropland,whereas their highest values were detected in vegetable and orchard soils,respectively.The significant positive correlation(P<0.05)between the abundance of soil MGEs and ARGs suggests that horizontal gene transfer may facilitate the spread of antibiotic resistance in the agricultural soils in highly cultivated hilly areas.