摘要
      抗生素在医学和农业中的广泛使用导致环境中抗生素耐药性微生物和抗生素耐药性基因的积累，威胁人类健康并污染环境。阿维菌素在防治根结线虫方面有着广泛的应用。本研究调查了5年施用阿维菌素对农田烟草根际微生物组和抗病性的影响。对阿维菌素的环境风险进行了充分评估。采用宏基因组方法分析了阿维菌素处理土壤中的抗生素抗性细菌和抗生素抗性基因。阿维菌素的应用影响了抗生素抗性细菌及其抗生素抗性基因的丰度和分布。抗生素抗性变形杆菌在根际土壤中所占比例最高（36%），携带530个ARGs。携带抗生素抗性基因的机会主义人类病原体在阿维菌素处理的土壤中富集。阿维菌素的应用增加了许多类型抗生素耐药性基因的计数。阿维菌素处理土壤中adeF、BahA、fusH、ileS和tlrB基因的相对丰度显著高于未处理的对照土壤。阿维菌素处理的土壤表现出不同的抗性机制。抗生素的流出（670个ARGs）、抗生素的失活（475个ARGs.）和抗生素靶点的改变（267个ARGs.）是主要的耐药机制。严格控制阿维菌素的剂量和使用频率以及其他农药可以降低土壤抗生素抗性基因，保护农产品的安全和公众健康。总体而言，杀线虫剂阿维菌素在农田土壤中的应用富集了抗生素抗性细菌和抗生素抗性基因，应警惕环境保护。
Abstract
The extensive use of antibiotics in medicine and agriculture has resulted in the accumulation of antibiotic-resistant microorganisms and antibiotic resistance genes (ARGs) in environments, which threaten human health and contaminate environment. Nematicide avermectin is widely applied to control root-knot nematodes. The effect of five-years application of avermectin on rhizosphere microbiome and resistome of sick tobacco plants in farmland were investigated in present study. The environmental risks of avermectin was assessed adequately. Metagenomic method was used to analyze antibiotic-resistant bacteria and antibiotic resistance genes in the avermectin-treated soil. The abundance and distribution of antibiotic-resistant bacteria and their antibiotic resistance genes were affected by avermectin application. The antibiotic resistant Proteobacteria occupied the highest percentage (36%) in rhizosphere soil and carried 530 ARGs. Opportunistic human pathogens carrying antibiotic resistance genes were enriched in the avermectin-treated soil. Avermectin application increased the counts of many types of antibiotic resistance genes. The relative abundances of genes adeF, BahA, fusH, ileS, and tlrB in the avermectin-treated soil were significantly greater than in the untreated control soil. Different resistance mechanisms were revealed in the avermectin-treated soil. The efflux of antibiotic (670 ARGs), inactivation of antibiotic (475 ARGs), and alteration of antibiotic target (267 ARGs) were the main resistance mechanisms. Rigid control the avermectin dose and use frequency and other pesticides can decrease soil antibiotic resistance genes and protect agricultural products’ safety and public health. Overall, application of nematicide avermectin enriched antibiotic-resistant bacteria and antibiotic resistance genes in farmland soil, which should be on the alert for environment protection.

https://www.sciencedirect.com/science/article/abs/pii/S0013935123005947