Antifungal susceptibilities of Sporothrix albicans, S. brasiliensis, and S. luriei of the S. schenckii complex identified in Brazil

Abstract

We studied 40 strains of the species complex formerly classified as the single species Sporothrix schenckii to identify new species within this complex and evaluate their antifungal susceptibility profiles. Based on phenotypic tests (ability to grow at 37°C, colony diameters, and pigmentation of the colonies, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), here we report the identification of S. albicans, S. brasiliensis, S. luriei, and S. schenckii; two isolates of these species were detected as itraconazole-resistant strains.

Fig. 1.

Evolutionary relationship of 15 taxa (linearized). The evolutionary history was inferred using the neighbor-joining method (14). The optimal tree is shown, with the sum of branch lengths = 0.63953762. The percentages of replicate trees in which the associated taxa clustered together in the bootstrap test (1,000 replicates) are shown next to the branches (5). The tree is drawn to scale, and branch lengths are in the same units as the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the maximum composite likelihood method (16) and are in units representing the number of base substitutions per site. All positions containing gaps and missing data were eliminated from the data set (complete deletion option). There were a total of 265 positions in the final data set. Phylogenetic analyses were conducted with MEGA software version 4.0 (17).