Identification of common species of dermatophytes by PCR-RFLP.

To establish a simple, sensitive and effective technique for the identification of six common dermatophytes, polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) targeting Topoisomerase II gene were used. The DNA of 6 common dermatophytes was amplified by primer dPsD1 and then primers dPsD2. The products generated by dPsD2 were digested with restriction enzyme Hinc II and Hinf I separately. A DNA fragment of about 3390 bp was amplified by using primer dPsD1 from the genomic DNA of each dermatophyte species. The product of dPsD2 was 2380 bp and the restriction profiles of Hinc II and Hinf I were between 58-1670 bp. By using PCR-RFLP, all of the 6 dermatophytoses were diagnosed to species level and no obvious difference identification between Hinc II and Hinf I. It is concluded that the PCR-RFLP identification of dermatophytes by Hinc II or Hinf I is efficient and rapid in clinical practice.