Sequence analysis of the ribosomal DNA intergenic spacer 1 regions of Trichosporon species.
We determined the sequence of the intergenic spacer (IGS) 1 region, which is located between the 26S and 5S rRNA genes, in 25 species of the genus TRICHOSPORON: IGS 1 sequences varied in length from 195 to 719 bp. Comparative sequence analysis suggested that the divergence of IGS 1 sequences has been greater than that of the internal transcribed spacer regions. We also identified five genotypes of T. asahii, which is a major causative agent of deep-seated trichosporonosis, based on the IGS 1 sequences of 43 strains. Most of the isolates that originated in Japan were of genotype 1, whereas the American isolates were of genotype 3 or 5. Our results suggest that analysis of IGS regions provides a powerful method to distinguish between phylogenetically closely related species and that a geographic substructure may exist among T. asahii clinical isolates.
Sugita
Takashi
T
Department of Microbiology, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan. sugita@my-pharm.ac.jp
Nakajima
Masamitsu
M
Ikeda
Reiko
R
Matsushima
Toshiharu
T
Shinoda
Takako
T
D000818:Animals; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics*; D006801:Humans; D007438:Introns; D009181:Mycoses / Q000175:diagnosis* / Q000662:veterinary; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D016415:Sequence Alignment; D014250:Trichosporon / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; C065096:RNA, ribosomal, 26S