Morphological and molecular identification of two strains of dermatophytes

Abstract

In this study, we used traditional morphological and molecular identification methods to preliminarily identify two strains of dermatophytes. The two strains were observed under the microscope. And then the dermatophytes were cultured on Sabouraud’s dextrose agar (SDA). The 18S rRNA regions of the two dermatophyte strains were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced and compared with GenBank data. BLAST tools and DNAMAN software were used to analyze the sequences. To further determine highly homologous sequences, a phylogenetic tree was constructed using the Neighbor-Joining method. The two strains of dermatophytes were identified by traditional morphological identification as Epidermophyton floccosum and Microsporumferrugineum. The 18S rRNA sequence analyses showed high similarities to Cladosporiumcladosporioides isolate C115LM-UFPR and Ascomycete sp. LB68A1A2. Epidermophyton and Cladosporium belong to dermatophyte, while Microsporum ferrugineum and Ascomycete belong to microsporum. The two novel strains of dermatophytes were therefore identified as Cladosporiumcladosporioides isolate C115LM-UFPR (JN650537, Cladosporium) and Ascomycete sp. LB68A1A2 (AY770409, Ascomycete sp).

Keywords

dermatophyte / identification / polymerase chain reaction / gene sequencing

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