NDM-1基因在纳污水环境微生物菌群的多态性分布及传播扩散机制

项目名称： NDM-1基因在纳污水环境微生物菌群的多态性分布及传播扩散机制

项目编号： No.31470440

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生态学

项目作者： 毛大庆

作者单位： 南开大学

项目金额： 88万元

中文摘要： 本研究针对NDM-1基因污染水域，拟用野外采样和室内模拟结合的方法，开展NDM-1基因在水环境菌群中的多态性分布和传播扩散机制研究。首先，以排放污水地点为起点，沿着受纳水体污染物扩散方向，布设采样点，采取水和沉积物样本，同时检测分析水生态因子。定性定量分析NDM-1基因，分离携带NDM-1基因的抗性细菌，并通过16S rDNA测序和Biolog鉴定细菌，再进一步通过细菌种特异序列定量细菌，逐步解析菌群结构；然后，从分离细菌中提取质粒DNA，实施质粒测序，对转移等机制进行分子分析；最后，通过实验室构建的各类模拟体系（同属种接合、异属接合、转化等）分析NDM-1基因的水平转移效率，及各因子对NDM-1基因转移机制影响，通过构建含有人类条件致病菌的模拟体系，考察NDM-1基因由环境传至人致病菌的风险。本研究对揭示NDM-1基因在水体中的传播机制，制定措施降低公共健康风险，具有理论和现实意义。

中文关键词： 分子机制；NDM-1基因；传播扩散；环境细菌；质粒

英文摘要： Our study focuses the distribution and the propagation-proliferation mechanism of the NDM-1 genes in water-environment microflora of NDM-1 genes pollution waters, with the approaches of analyzing field samples and building laboratory aquatic microcosm. Firstly, the sampling map is designed according to the standards along the orientation of contaminant diffusion in the waters accepted sewage effluent, and water and sediment samples are collected meanwhile implementing detection of ecological factors. NDM-1 genes can be firstly detected qualitatively by PCR, and then quantified by RTQ-PCR. Some bacteria carrying NDM-1 gene will be isolated, and identified by 16S rDNA sequencing and Biolog system. These species specific sequences of the isolates will be treated as indicators of these resistance strains, which indicator will help us to analyze composition of microflora by RTQ-PCR. Secondly, plasmid is extracted from the isolates, and full sequences of these plasmids are sequenced by pyrosequencing. Molecule analysis is carried out on the plasmid sequences, and classification and transfer mechanism of plasmids are focused on with bioinformatics methods. Finally, several microcosm systems, such as conjugations of same genus bacteria, conjugation of different genus bacteria and transformation system, will applied to detect the horizontal transfer of NDM-1 genes undergoing the influences of ecological factors. An opportunistic pathogen of mankind is even included in the microcosm system to indicate the ecological risk of NDM-1 genes. Our study has a potential theoretical and practical significance preventing the propagation of NDM-1 genes in the waters.

英文关键词： molecular mechanism;NDM-1 gene;propagation;environmental bacteria;plasmid