Department of Pathology and Legal Medicine, College of Medicine, Post-Graduation Program in Medical Microbiology, Specialized Medical Mycology Center, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
Department of Preventive Veterinary Medicine and Animal Health, College of Veterinary Medicine, Universidade de São Paulo, São Paulo, Brazil.
J Med Microbiol. 2012 Dec;61(Pt 12):1688-1695. doi: 10.1099/jmm.0.044073-0. Epub 2012 Sep 13.
Since the beginning of the HIV epidemic, there has been a significant increase in the number of histoplasmosis cases in Ceará, a state in north-east Brazil. The lack of epidemiological data on the genotypes circulating in the north-east region shows the importance of more detailed studies on the molecular epidemiology of Histoplasma capsulatum var. capsulatum in this region. Different molecular techniques have been used to better characterize the genetic profile of H. capsulatum var. capsulatum strains. The aim of this study was to analyse the genetic diversity of H. capsulatum var. capsulatum isolates in Fortaleza, the capital of Ceará, through the sequencing of the internal transcribed spacer (ITS)1-5.8S-ITS2 region, and establish the molecular profile of these isolates, along with strains from south-east Brazil, by RAPD analysis, featuring the different clusters in those regions. The isolates were grouped into two clusters. Cluster 1 included strains from the south-east and north-east regions with separation of isolates into three distinct subgroups (subgroups 1a, 1b and 1c). Cluster 2 included only samples from north-east Brazil. Sequencing of the ITS1-5.8S-ITS2 region allowed the detection of two major clades, which showed geographical correlation between them and their subgroups. Therefore, it can be concluded that the H. capsulatum var. capsulatum isolates from Ceará have a high degree of genetic polymorphism. The molecular data also confirm that populations of this fungus are composed of different genotypes in Brazil and worldwide.
自艾滋病流行开始以来，巴西东北部塞阿拉州的组织胞浆菌病病例数量显著增加。东北区域流行的基因型缺乏流行病学数据，这表明在该区域进行荚膜组织胞浆菌荚膜变种的分子流行病学更详细研究的重要性。不同的分子技术已被用于更好地描述荚膜组织胞浆菌荚膜变种菌株的遗传特征。本研究的目的是通过测序内部转录间隔区（ITS）1-5.8S-ITS2 区域，分析塞阿拉州首府福塔莱萨荚膜组织胞浆菌荚膜变种分离株的遗传多样性，并结合来自巴西东南部的菌株，通过 RAPD 分析建立这些分离株的分子特征，同时分析这些地区的不同聚类。分离株分为两个聚类。聚类 1 包括来自东南部和东北部地区的菌株，将分离株分为三个不同的亚群（亚群 1a、1b 和 1c）。聚类 2 仅包括来自东北部巴西的样本。ITS1-5.8S-ITS2 区域的测序检测到两个主要的分支，它们在地理上与它们的亚群相关。因此，可以得出结论，来自塞阿拉州的荚膜组织胞浆菌荚膜变种分离株具有高度的遗传多态性。分子数据还证实，巴西和全球范围内的该真菌种群由不同的基因型组成。
