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Genetic analysis of the photoreactivation system in Pseudomonas cepacia

洋葱假单胞菌光活化系统的遗传分析

基本信息

批准号：
63570190
负责人：
MATSUMOTO Hideki
金额：
$ 1.41万
依托单位：
Department of Bacteriology, School of Medicine, Shinshu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63570190/
关键词：
PSEUDOMONAS CEPACIA ULTRAVIOLET SENSITIVITY PHOTOREACTIVATION GENETIC ANALYSIS

项目摘要

Pseudomonas cepacia was initially described as a phytopathogen. However, association of this bacterium, as an opportunistic pathogen, with human infections has been now well documented. In 1975, Carson and Petersen noted, for a P.cepacia strain of natural origin, a potent photoreactivation. This would pose a serious problem in hospitals where contaminations of aseptic solutions, anesthetics, a transplantation tissue and surgical equipments by P.cepacia have been reported. Thus, this purpose was aimed at knowing the genetic organization of the photoreactivation in P.cepacia. A clinical isolate of P.cepacia, strain PCJ, was selected as being suitable for the study from among about 100 strains.In wild-type strain of the P.cepacia, a potent photoreactivation was indeed demonstrated for the cells exposed to ultraviolet( UV ), that is, number of colonies on the plates incubated in the light were 10^2 to 10^4 times larger than that of the plates kept in the dark at a same temperature. Sevente … More en mutants that were sensitive to UV could be derived from the wild-type cells treated with methanesulfonic acid ethyl ester( EMS ). In marked contrast to the wild-type, when the mutant cells were exposed to UV, they were all nearly unable to form colony both in the light and in the dark, suggesting that they lost the photoreactivating activity. No difference was seen between the wild-type and the UV-sensitive mutants in their susceptibility to EMS and N-methyl-N'-nitro -N-nitrosoguanidine. With respect to the ability to survive from the exposure to UV, a close resemblance was observed between the wild-type cells of P.cepacia and those of the E.coli with a uvra mutation. These results indicated that in P.cepacia photoreactivation was playing a very important role, if not unique, in repairing the damage of DNA caused by UV irradiation. With the intention of cloning the gene(s) that participating in the photoreactivation, attempts were made to isolate, from a chromosomal gene library of the P.cepacia, any clone that complements a phr ( photoreactivation ) mutation of a E.coli. A clone that could do so has been found and this suggested that there would be a photoreactivation system in P.cepacia which functions biochemically in a manner that is similar to that of E.coli. Subcloning of the gene(s) concerned is in progress. Less

洋葱假单胞菌最初被描述为植物病原体。然而，这种细菌作为一种机会致病菌与人类感染的关联现在已经有了很好的记录。1975年，卡森和彼得森注意到，一种天然来源的洋葱疫霉菌株具有强有力的光复活作用。这将在医院中造成严重的问题，其中已经报道了洋葱伯克霍尔德菌对无菌溶液、麻醉剂、移植组织和手术设备的污染。因此，这一目的的目的是了解在洋葱光复活的遗传组织。从约100株洋葱假单胞菌中筛选出一株适合于本研究的临床分离株PCJ，在洋葱假单胞菌野生型菌株中，确实证明了暴露于紫外线（UV）的细胞具有有效的光复活作用，即，在光照下培养的平板上的菌落数比在相同温度下避光培养的平板上的菌落数大10^2至10^4倍。塞文特 ...更多信息用甲基磺酸乙酯（EMS）处理野生型细胞，可获得对紫外线敏感的突变株。与野生型相比，突变体细胞在紫外线照射下，无论在光照还是黑暗条件下，几乎都不能形成集落，表明突变体细胞失去了光复活活性。在对EMS和N-甲基-N '-硝基-N-亚硝基胍的敏感性方面，野生型和UV敏感突变体之间没有观察到差异。关于从暴露于UV中存活的能力，在洋葱假单胞菌的野生型细胞和具有uvra突变的大肠杆菌的细胞之间观察到非常相似。这些结果表明洋葱光复活在修复紫外线损伤的DNA中起着非常重要的作用，如果不是唯一的话。为了克隆参与光复活的基因，尝试从洋葱假单胞菌的染色体基因文库中分离任何补充大肠杆菌phr（光复活）突变的克隆。已经发现了一个可以这样做的克隆，这表明洋葱疫霉中可能有一个光复活系统，其生物化学功能与大肠杆菌相似。有关基因的亚克隆正在进行中。少