泰乐菌素/胞外DNA在粘土矿物界面的共吸附行为及DNA耐药性变化

Migration and transformation behavior of antibiotics have been a highly attractive field. However, the reports pay main attention to kinds of antibiotic adsorption on different environmental medium. Littler studies are about combination contamination of antibiotics, especially for the interaction of antibiotic and the extra-cellular DNA. After a long time interaction with antibiotics, the extra-cellular DNA may be antibiotic resistance. The charge and possible resistance of extra-cellular DNA may affect the transmission of amphoteric antibiotic and antibiotic resistance. Therefore, base on our previous work, tylosin and extra-cellular DNA will be chosen as the objects in our study，as well as clay minerals. Because clays are closely relate with both of the environmental behavior of tylosin and extra-cellular DNA. Various characterization techniques will be utilized comprehensively to discuss the effects of tylosin on DNA structure. The extra-cellular DNA interacted with tylosin will be extracted from clay. And then，antibiotic resistance test will be measured to clarify the role of antibiotics in the resistance changing process of extra-cellular DNA. The co-sorption behavior of tylosin/DNA at the clay mineral interface will be investigated. This will reveal the interaction mechanism of tylosin/extra-cellular DNA at the mineral interface. The project will provide lots of basic information. This information will further clarify the mobility 、 transfer、accumulation rules of antibiotics and extra-cellular DNA in the environment and help understand the function of the two compound in the process of resistance gene horizontal transfer. It will be of important theoretical significance for correct assessment of antibiotic resistance risk.

抗生素迁移转化行为研究是当前抗生素污染研究的热点。但目前的报道主要关注不同种类抗生素在不同环境介质中的吸附。而对抗生素与其它污染物的复合污染，尤其是与可能产生耐药性的胞外DNA在环境介质中的相互作用研究较少。胞外DNA可能因为带电性质的变化和耐药性的产生而影响两性物质抗生素及其耐药性的传播。因此本项目拟在前期工作基础上，选择泰乐菌素、胞外DNA及与两者环境行为密切相关的粘土矿物为对象，利用多种表征技术探讨泰乐菌素对DNA结构影响。通过提取泰乐菌素作用下粘土矿物上的DNA并对其进行耐药性实验，阐明抗生素在胞外DNA耐药性变化中的作用。研究该双组分体系在粘土矿物界面的吸附，揭示抗生素和胞外DNA在矿物界面的相互作用机制。本项目为进一步阐明抗生素和胞外DNA在环境中的迁移、转化和富集规律及它们在耐药基因水平转移过程中的作用提供了大量的基础信息，具有重要的理论意义。

抗生素与其它污染物的复合污染是当前抗生素污染研究的热点，但抗生素与环境介质中普遍存在的生物活性物质的相互作用研究较少，例如胞外DNA。基于以上背景，项目以泰乐菌素、胞外DNA及与两者环境行为密切相关的粘土矿物为对象，首先考察了不同水溶液条件下泰乐菌素与DNA的相互作用规律。同时采用淋滤的方法，考察DNA和泰乐菌素在蒙脱石柱中的穿透情况。在此基础上研究该双组分体系在粘土矿物界面的吸附。取得了以下成果：（1）研究了水溶液中泰乐菌素和DNA相互作用机制；（2）初步确定了泰乐菌素会影响粘土矿物对DNA的保护作用；（3）阐明了泰乐菌素和DNA在矿物界面的相互作用机理。本项目研究成果为进一步阐明抗生素和胞外DNA在环境中的迁移、转化和富集规律提供重要的实验数据，具有重要的理论意义。