Use of Padlock Probes and Rolling Circle Amplification (RCA) for Rapid Identification of Trichophyton Species, Related to Human and Animal Disorder

Zakeri, Hamideh; Shokohi, Tahereh; Badali, Hamid; Mayahi, Saba; Didehdar, Mojtaba

Numerous recent articles and reviews have exhaustively discussed the various molecular techniques available for dermatophyte species identification. Molecular tools, such as sequencing of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA), have shown promise for species identification in all genera of dermatophytes, and is relatively expensive (4-7). Moreover, ITS-based analyses have found that sequence variation is limited to only one or a few single nucleotide polymorphisms (SNPs) between certain species, e.g., T. tonsurans and T. equinum or T. rubrum and T. soudanense (7) . This limited genetic variation suggests that the development of alternative molecular tools with sufficient specificity, reproducibility, and sensitivity is highly necessary (8) . Rolling-circle amplification (RCA) is a powerful and simple procedure for distinguishing closely related taxa at the species level; it is based on the rolling replication of short single-stranded DNA circles via specific DNA polymerases under isothermal conditions. This enables the detection of target nucleic acid sequences, including SNPs, with high specificity (9-12).