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

Previous studies have shown that Trichophyton species have several unique nucleotide positions suitable for the development of specific padlock probes for species characterization; these can be used to distinguishing closely related species (8) . In this study, species-specific padlock probes were used to distinguish three species of Trichophyton, T. mentagrophytes, T. rubrum, and T. tonsurans. Using species-specific probes, we correctly identified all clinical isolates. Three standard species of Trichophyton, T. rubrum (CBS 130927), T. mentagrophytes var. interdigitale (NBRC 5812), and T. tonsurans (NBRC 5928) were also positively identified using only the species-specific padlock probes. The sequencing results for the ITS regions of rDNA showed 100% concordance with the RCA results. Additionally, these results were perfectly concordant with phenotypic identification. The RCA procedure required less than one working day, including DNA extraction, PCR amplification, hybridization, ligation of padlock probes, and RCA amplification, rather than sequencing.