摘要
      随着抗生素的广泛使用，抗生素耐药性基因（ARGs）问题逐渐出现。由于农业土壤是抗生素和ARGs的重要富集介质，研究ARGs毒性、各种营养物质和污染物的影响，以及如何通过源头改造和过程调控来控制它们，显得尤为重要。在本研究中，采用来源修饰和过程调控相结合的方法来削弱喹诺酮类（QNs）ARGs在不同农业地区土壤中的毒性表达。并将探讨土壤养分和污染物对这一过程的影响。蛋白质-蛋白质对接和分子对接用于构建QNs’ARGs毒性表达的靶蛋白复合物，并表征QNs’ARGs的毒性。二维和三维定量构效关系模型构建和灵敏度分析用于分子修饰和相关验证。以东北地区和长江中下游地区的农业土壤为研究对象，采用抽样调查方法进行分子动力学模拟，生成四种情景。主要结果是：（a）设计了一种功能改进、环境友好的喹诺酮类衍生物（ORB–19）。它可以有效抑制QNs的ARGs的表达，降低抗生素选择压力的风险。ORB–19在农业地区的应用可显著抑制QNs ARGs的毒性表达（112.75%～169.59%）；（b） QNs的ARGs在营养元素较高的东北农业区具有较强的毒性表达；（c） 不同类型的农业污染对抑制农业土壤中QNs’ARGs毒性表达的贡献各不相同；（d） 在不同农业污染类型的地块之间，为抑制QNs的ARG毒性表达而提供的应用田间措施的选择各不相同。本研究为抑制QNs的ARGs在土壤环境中的毒性表达、减少ARGs对微生物种群的传播、取代绿色QNs衍生物以及农业土壤的可持续发展提供了理论支持。
Abstract
With the extensive use of antibiotics, the problem of antibiotic resistance genes (ARGs) has gradually emerged. As agricultural soil is an important enrichment media of antibiotics and ARGs, it is particularly important to study the toxicity of ARGs, the effects of various nutrients and pollutants, and how to control them through source modification and process regulation. In this study, a combination of source modification and process regulation was used to weaken the toxic expression of Quinolones’ (QNs’) ARGs in soils from different agricultural areas. And the influence of soil nutrients and pollutants on this process will be explored. Protein-protein docking and molecular docking were used to construct a target protein complex for the toxic expression of QNs’ ARGs and characterize the toxicity of QNs’ ARGs. The two-dimensional and three-dimensional quantitative structure-activity relationships model construction and sensitivity analysis were used to molecular modification and related validation. Molecular dynamics simulations assisted by sampling survey method based on agricultural soils in Northeast China and the lower-middle reaches of the Yangtze River were carried out to generate four scenarios. The main results are: (a) A functionally improved and environmentally friendly quinolone derivative (ORB–19) was designed. It can effectively inhibit the expression of QNs’ ARGs and weaken the antibiotic selection pressure risk. The application of ORB–19 in agricultural areas could significantly inhibit the toxic expression of QNs’ ARGs (112.75%~169.59%); (b) QNs’ ARGs have a stronger toxic expression in agricultural areas of Northeast China, which have higher nutrient elements; (c) The contribution of different types of agricultural pollution to suppressing the toxic expression of QNs' ARGs in agricultural soils varies; (d) The options of applied field measures given for the inhibition of QNs’ ARG toxic expression varied between plots with different agricultural pollution types. This study provides theoretical support for inhibiting the toxic expression of QNs’ ARGs in the soil environment, reducing the spread of ARGs in microbial populations, replacing green QNs derivatives, and sustainable development of agricultural soils.

https://www.sciencedirect.com/science/article/pii/S0147651322006467