Evolution of CDC42, a putative virulence factor triggering meristematic growth in black yeasts

Global Spread of Human Chromoblastomycosis Is Driven by Recombinant Cladophialophora carrionii and Predominantly Clonal Fonsecaea Species

Global distribution patterns of Cladophialophora carrionii, agent of human chromoblastomycosis in arid climates of Africa, Asia, Australia, Central-and South-America, were compared with similar data of the vicarious Fonsecaea spp., agents of the disease in tropical rain forests. Population diversities among 73 C. carrionii strains and 60 strains of three Fonsecaea species were analyzed for rDNA ITS, partial β-tubulin, and amplified fragment-length polymorphism (AFLP) fingerprints. Populations differed significantly between continents. Lowest haplotype diversity was found in South American populations, while African strains were the most diverse. Gene flow was noted between the African population and all other continents. The general pattern of Fonsecaea agents of chromoblastomycosis differed significantly from that of C. carrionii and revealed deeper divergence among three differentiated species with smaller numbers of haplotypes, indicating a longer evolutionary history.

Draft Genome Sequence of Herpotrichiellaceae sp. UM 238 Isolated from Human Skin Scraping

Herpotrichiellaceae spp. are known to be opportunistic human pathogens. Here, we report the ~28.46-Mb draft genome of Herpotrichiellaceae sp. UM 238, isolated from human skin scraping. The UM 238 genome was found to contain many classes of protective genes that are responsible for fungal adaptation under adverse environmental conditions.

Molecular characterization of pathogenic members of the genus Fonsecaea using multilocus analysis

Members of the fungal genus Fonsecaea causing human chromoblastomycosis show substantial geographic structuring. Genetic identity of clinical and environmental strains suggests transmission from plant debris, while the evolutionary processes that have led to spatially separated populations have remained unexplained. Sequences of ITS, BT2, ACT1, Cdc42, Lac and HmgA were analyzed, either by direct sequencing or by cloning. Thirty-seven clinical and environmental Fonsecaea strains from Central and South America, Asia, Africa and Europe were sequenced and possible recombination events were calculated. Phylogenetic trees of Cdc42, Lac and HmgA were statistically supported, but ITS, BT2 and ACT1 trees were not. The Standardized Index of Association (I_A^S) did not detect recombination (I_A^S = 0.4778), neither did the Phi-test for separate genes. In Fonsecaea nubica non-synonymous mutations causing functional changes were observed in Lac gene, even though no selection pressures were detected with the neutrality test (Tajima D test, p>0.05). Genetic differentiation of populations for each gene showed separation of American, African and Asian populations. Strains of clinical vs. environmental origin showed genetic distances that were comparable or lower than found in geographic differentiation. In conclusion, here we demonstrated clonality of sibling species using multilocus data, geographic structuring of populations, and a low functional and structural selective constraint during evolution of the genus Fonsecaea.