Microsatellite analysis of three phylogenetic species of Paracoccidioides brasiliensis

Abstract

Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, an important human systemic mycosis in Latin America. Recently, the existence of three different phylogenetic species (S1, PS2, and PS3) of P. brasiliensis was demonstrated. Despite being genetically isolated, all three species were capable of inducing disease in both humans and animals, although lower virulence has been found with the PS2 species. The available molecular methods developed to characterize and type strains have not been useful for assigning isolates to the described species, creating the need for molecular markers capable of distinguishing genetically isolated groups. Here, we describe a PCR and sequencing-based microsatellite marker system that is stable, easy to assay, adaptable to large series of isolates, and discriminatory enough to be used as a typing system in identifying the three proposed species of P. brasiliensis. In addition, this system provides an unambiguous tool for strain discrimination between two (S1 and PS2) of the three phylogenetic species.

FIG. 1.

Scatterplots of the number of repeats of two selected microsatellites. (A) PBMS1 versus PBMS4; (B) PBMS3 versus PBMS4; (C) PBMS4 versus PBMS5. The three selected microsatellite pairs correspond to those that are useful for the recognition of the three P. brasiliensis phylogenetic species.