Isolation and wall analysis of dimorphic mutants of Paracoccidioides brasiliensis.

Nitrosoguanidine treatment of Paracoccidioides brasiliensis strain IVIC Pb73 induced a set of mutants affected in their ability to complete dimorphism. Some did not transform to the typical mycelial form, while others did not grow as yeasts. These mutants were preliminarily characterized by microscopic observations and the study of some of their properties: optimal growth temperature, nutritional requirements, virulence and cell wall analyses. Comparison of these properties allowed the classification of the mutants in 4 functional categories with respect to dimorphism.