Phylogenetic Relationships of Varieties and Geographical Groups of the Human Pathogenic Fungus Histoplasma capsulatum Darling

摘要: The phylogeny of 46 geographically diverse Histoplasma capsulatum isolates representing the three varieties capsulatum, duboisii, and farciminosum was evaluated using partial DNA sequences four protein coding genes. Parsimony distance analysis separate genes were generally congruent combined data identified six clades: (i) class 1 North American H. var. (ii) 2 (iii) Central (iv) South group A, (v) B, (vi) duboisii. Although clades well supported, relationships among them not resolved nearest outgroups (Blastomyces Paracoccidioides) too distant to unequivocally root tree. found within A clade. With exception clade, genetic distances an order magnitude lower than those between clades, each clade supported by a number shared derived nucleotide substitutions, leading conclusion that genetically isolated from others. Under phylogenetic species concept based on possession multiple characters, as concordance gene genealogies, could be considered harbor instead varieties. pathogenic ascomycete Darling [teleomorph, Ajellomyces capsulatus (Kwon-Chung) McGinnis et Katz] occurs throughout world causes histoplasmosis in various mammalian species, including humans (46, 61). fungus grows saprobe nature is acquired inhalation airborne microconidia or hyphal fragments. Once inhaled, transforms mycelium yeast form. Histoplasmosis primarily affects host’s lungs, its symptoms vary greatly. vast majority infected people are asymptomatic; however,