Abstract

The maintenance of fungi isolates and the development of methodologies were available from their phenotypic and genotypic characteristics. Alterations of Histoplasma capsulatum and Candida spp. Strains preserved by continuous subculturing on fungal collection and by lyophilization for 35 years were evaluated. Candida isolates maintained by lyophilized methodology were viable and preserved by the typical characteristics of each species. Only one lyophilized isolate from H. capsulatum was viable and demonstrated typical morphology. Both genus, which were preserved by continuous subculturing, revealed morphologic alterations and lost their sporulation capacity. The DNA from these isolates was sequenced (conserved 28S rDNA) in order to confirm their identity. Random amplified polymorphism DNA (RAPD)-based comparative analysis of the two preservation methods revealed alterations in the band profiles in 28 and 33% inCandida spp. and Histoplasma capsulatum strains respectively. The RAPD-based results confirm that the subculturing method alters phenotypic and genotypic characteristics by deleting or inserting nucleotides. Otherwise, the lyophilization was effective to yeasts, but it was not effective for dimorphic fungi.

Key words: Polymorphism, genotypic characteristics, lyophilization, random amplified polymorphism DNA.