Identification of Medically Relevant Trichosporon Species Based on Sequences of Internal Transcribed Spacer Regions and Construction of a Database for Trichosporon Identification

ABSTRACT The nucleotide sequences of the internal transcribed spacer (ITS) 1 and 2 regions in the rRNA gene were determined by directly sequencing PCR-amplified fragments for all of the species (17 species and five varieties) in the genus Trichosporon . Comparative sequence analysis suggests that six medically relevant species, T. asahii , T. asteroides , T. cutaneum , T. inkin , T. mucoides , and T. ovoides , can be readily identified by their ITS sequences. In addition, the sequence analysis showed that conspecific strains have fewer than 1% nucleotide differences in the ITS 1 and 2 regions overall. Molecular phylogenetic trees are also presented.