Genetic ecology of pathogenic fungi in Brazil

在本工作中，获得了以下新的证据。建立了一种在欧美等世界范围内高度分布，但在亚洲较低的皮肤真菌--托氏毛霉菌的遗传鉴定方法。此外，从世界不同地区分离的菌株之间没有遗传差异。为研究3种暗色真菌--腐烂枝孢霉(Cladhialophora Carrioni)、圆顶孢霉(Fonsecaea Pedrosoi)和疣状隐孢子菌(Phialophora Verrucosa)的遗传变异，采用随机扩增多态性DNA技术(RAPD)对世界各地采集的菌株进行了分析。结果表明，同一国家或地区分离的菌株具有不同于其他地区的高度同源性。巴西拟球孢子菌病是一种仅见于拉丁美洲的深部真菌病，对其生理和形态特征进行了研究，以确定其表型。对采集自巴西的菌株进行的随机扩增多态性DNA分析表明，供试菌株在遗传上可分为两组。根据已知的细胞色素b氨基酸序列设计的新引物可用于曲霉致病菌种的鉴定和系统发育研究。

In the present work, following new evidences were obtained.1. Genetic identification method of Trichophyton tonsurans, a dermatophyte which is highly distributed in world wide as European and both American countries but low in Asia, was established. Furthermore, it was demonstrated that there is no genetically different among the strains isolated from various regions of the world.2. To study genetic variations of three dematiaceous fungi, Cladophialophora carrioni, Fonsecaea pedrosoi and Phialophora verrucosa which are causative agents of chromoblastomycosis, random amplified polymorphic DNA analysis (RAPD) was applied to the isolates collected from vaiious areas of the world. The results showed that the strains isolated from the same country or area had genetically high homogeneous pattern differed from those of other areas.3. The physiological and morphological features of Paracoccidioides brasiliensis, the causative agent of paracoccidioidomycosis which is a deep mycosis limited to Latin America, were studied in order to define their phenotype. RAPD analysis for the strains collected in Brazil showed that the tested strains could be separated in two groups genetically.4. The newly designated primers from known cytochrome b amino acid sequences were found to be useful for identification and phylogenetic study of pathogenic species of Aspergillus.