title: Genetic diversity of Histoplasma capsulatum strains isolated from Argentina based on nucleotide sequence variations in the internal transcribed spacer regions of rDNA.
abstract: The internal transcribed spacer (ITS) regions of rDNA genes of 49 Histoplasma capsulatum (48 from clinical samples and one from soil) isolates were examined. Nucleotide sequence heterogeneity within this region was useful for phylogenetic classification of H. capsulatum and species identification. Thus, in 45 of 49 isolates we observed higher percentages of identity in the nucleotide sequences of ITS regions when the isolates studied herein were compared with those reported in our country in the South America B clade. Phylogenetic analyses of rDNA sequences corresponding to the 537 bp of the ITS region obtained from H. capsulatum isolates assigned South America type B clade (45 isolates), North America type 1 and Asia clade (2 isolates each one). H. capsulatum strains isolated from soil and from patients living in Argentina (45 of 49) clustered together with the H. capsulatum isolates of the South America B clade. The high level of genetic similarity among our isolates suggests that almost one genetic population is present in the microenvironment. Isolates described as H. capsulatum var. capsulatum or var. farciminosum (2 isolates) did not form a monophyletic group and were found in the Asia clade. Subsequent studies are needed to properly identify these isolates.
authors.affiliation: Instituto of Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Landaburu
authors.forename: María Luján
authors.initials: ML
authors.lastname: Cuestas
authors.forename: Andrea
authors.initials: A
authors.lastname: Rubio
authors.forename: Nahuel Alejandro
authors.initials: NA
authors.lastname: Elías
authors.forename: Gabriela Lopez
authors.initials: GL
authors.lastname: Daneri
authors.forename: Cecilia
authors.initials: C
authors.lastname: Veciño
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Iovannitti
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Mujica
mesh_terms: D000818:Animals; D001118:Argentina / Q000453:epidemiology; D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D014644:Genetic Variation; D006658:Histoplasma / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D006660:Histoplasmosis / Q000453:epidemiology / Q000382:microbiology* / Q000662:veterinary*; D006734:Horse Diseases / Q000382:microbiology; D006736:Horses; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer
keywords: Histoplasma capsulatum; ITS regions; South America B clade; phylogeny