铜绿假单胞菌中影响吩嗪合成基因操纵子phzA1的调节基因的研究

发布时间：2018-03-19 09:11

本文选题：铜绿假单胞菌　切入点：吩嗪　出处：《西北大学》2008年硕士论文　论文类型：学位论文

【摘要】： 铜绿假单胞菌(Pseudomonas aeruginosa)是一个分布广泛的机会致病菌[1],在烧伤病人、器官移植病人、免疫力低下病人,如接受化学治疗的癌症病人和艾滋病病人中,它几乎可以感染人体的任何组织并常常危及患者生命。它对许多抗生素具备很高的内在抗药性,并可产生许多致病因子,如碱性蛋白酶(alkalineprotease)和吩嗪(phenazine)等,是难以治疗的病原菌。绿脓菌素作为吩嗪的一种衍生物,不仅是一种致病因子,更重要的是作为铜绿假单胞菌中的一种信号分子。因此,研究吩嗪合成的调节途径对于了解铜绿假单胞菌的致病机制和微生物群体中不同细菌间的相互作用具有重要意义。本文运用转座子突变方法,对含有报道质粒miniCTX-phzAl的铜绿假单胞菌进行转座子随机突变,筛选影响吩嗪合成的调节突变体。筛选到了6个影响吩嗪合成的突变体,并对这6个突变体进行了鉴定,确定突变体中转座子插入位点,从而确定转座子所破坏的基因。并根据生物信息分析结果,推测其功能。研究结果为了解铜绿假单胞菌致病因子的调节机理提供了新的数据和线索。同时,对一个菌落和颜色发生明显变化的突变体进行的深入研究表明,该转座突变的基因是铜绿假单胞菌的一个新转录调节基因。并通过基因敲除的方法验证了该基因的功能。采用基因敲除的方法,构建了负责ABC转运系统的两个基因PA0602和PA4594基因的突变体。研究这两个基因是否参与低抑制浓度四环素对吩嗪合成基因phzAl的调节。探索了这两个基因与群体感应体调节系统和PQS系统之间一定的关系。
[Abstract]:Pseudomonas aeruginosa (Pseudomonas aeruginosa) is a widely distributed opportunistic pathogen in burn patients, organ transplant patients, immunocompromised patients, such as cancer patients receiving chemotherapy and AIDS patients. It can infect almost any human tissue and often endanger the life of patients. It has high intrinsic resistance to many antibiotics and can produce many pathogenic factors, such as alkaline protease, phenazine and phenazine, which are difficult to treat. As a derivative of phenazine, Pseudomonas aeruginosa is not only a pathogenic factor, but also a signaling molecule in Pseudomonas aeruginosa. It is important to study the regulatory pathway of phenazine synthesis for understanding the pathogenic mechanism of Pseudomonas aeruginosa and the interaction between different bacteria in microbial population. In this paper, transposon random mutation of Pseudomonas aeruginosa containing reporter plasmid miniCTX-phzAl was carried out by transposon mutation method to screen regulatory mutants affecting phenazine synthesis. Six mutants affecting phenazine synthesis were screened. The six mutants were identified and the transposon insertion sites were determined to determine the genes destroyed by transposons. The results provide new data and clues for understanding the regulatory mechanism of the pathogenic factors of Pseudomonas aeruginosa. At the same time, an in-depth study of a mutant with significant changes in colony and color showed that, The translocation mutant gene is a new transcriptional regulator of Pseudomonas aeruginosa and its function is verified by gene knockout. Using gene knockout, The mutants of two genes, PA0602 and PA4594, responsible for the ABC transport system, were constructed. Whether the two genes were involved in the regulation of phenazine synthesis gene phzAl by low inhibitory concentration tetracycline was studied. There is a certain relationship between the regulating system and the PQS system.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R378

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