Occurrence and distribution of antibiotics and antibiotic resistance genes in the different croplands along the Yellow River shoreline

Abstract

Many antibiotics and their related antibiotic resistance genes (ARGs) are found in agricultural soil, raising concerns for public and environmental health. As a result, it is crucial to examine the abundance of sulfonamides, fluoroquinolones, tetracyclines, macrolides, and β-lactam antibiotics and their corresponding ARGs in agricultural soils. We investigted the abundance of aadA, sul1, aac(6’)-Ib, tetX, tetA, ermB, mphB, qnrA, intI1, intI2, and ISCR1 genes and explore their relationships with antibiotics in rice, peach orchard, maize, peanut, and garlic croplands along the Yellow River in Zhongmu and Yuanyang, Henan Province. There was no significant difference across the five croplands (P > 0.05), however, the paddy field had the highest average concentration (>10 μg kg−1) of oxytetracycline, tetracycline, ciprofloxacin and norfloxacin antibiotics. The predominant ARGs were aadA, sul1, with the the highest number of ARGs and MGEs detected in paddy rice, followed by maize, peanut, garlic, and peach soils. Integrase gene intI1 was significantly greater than intI2 and ISCR1, which was positively linked with sul1, aadA, aac(6′)-Ib, tetA, tetX, and ermB genes (P < 0.05). According to redundancy analysis, antibiotics may accelerated the prevalence of ARGs. Redundancy analysis demonstrated that antibiotics contributed 78.7% of the total ARG variations. Notably, the concentration of oxytetracycline in all the croplands ranged from 10.33 to 14.42 μg kg−1, which had impacted the frequency of ermB, bla CTX-M, intI2, and mphB genes as demonstrated by RDA analysis. Results revealed that effective techniques are required to lower the prevalence of ARGs in the agroecosystems.