ABSTRACT
To re-identify and further group 25 isolates of Trichosporon spp. identified morphologically previously, sequences of D1/D2 region of large subunit (LSU) of ribosomal DNA (rDNA) of 25 tested strains for identification and those of ribosomal intergenic space 1 (IGS1) region of 11 strains for subgrouping were detected. The identifications of tested strains were changed except 6 strains. According to the alignment of the IGS1 region, 6 T. asahii isolates tested fell into 4 groups and 5 T. faecale isolates into 3 groups. Polymorphism of 2 T. japonicum isolates was found in 10 positions. With the alignments obtained in this research compared with the relative GenBank entries, it was found that T. asahii, T. faecale and T. japonicum species were divided into 7, 3 and 2 subtypes respectively. Morphological and biophysical methods are not sufficient for Trichosporon spp. identification. Sequencing becomes necessary for Trichosporon diagnosis. There is obvious diversity within a species.
ABSTRACT
BACKGROUND: T. tonsurans is an anthropophilic dermatophyte mostly causing tinea capitis and tinea corporis. In East Asian countries, it has rarely been isolated until now. However, it is necessary for researchers in Asian countries to be more accustomed to T. tonsurans than before because of frequent international sports exchanges nowadays. OBJECTIVES: This study was performed to identify T. tonsurans by random amplified polymorphic DNA (RAPD) analysis. METHODS: Fifteen strains which were tentatively identified as T. tonsurans in Brazil were identified again by several conventional mycological tests and RAPD analysis. RESULTS: Among 15 Brazilian strains, 3 were identified as T. tonsurans, 8 T. mentagrophytes, 3 T. nJmwn and 1 T. raubitschekii by conventional mycological tests. This result was examined again by RAPD analysis. CONCLUSION: RAPD analysis is considered a rapid and reliable method for identification of T. tonsurans if the procedure is carefully standardized with adequate-primers.