Utility of Real-time PCR for diagnosis of Dermatophytes in Indian patients with onychomycosis.

PURPOSE: Effective treatment of onychomycosis caused by dermatophytes (i.e. Trichophyton Microsporum and Epidermophyton) requires species identification and long-term systemic treatment. Traditional diagnosis of onychomycosis is based on KOH microscopy and fungal culture which have their own limitations. Molecular diagnostic methods such as real-time PCR offer shorter turnaround time, species identification and higher sensitivity. This study intended to define diagnostic ability of real-time PCR for dermatophyte detection in Indian patients with onychomycosis. METHODS: Nail samples from 65 clinically suspected onychomycosis patients were screened by conventional methods (KOH Microscopy and fungal culture) for detection of dermatophytes. Simultaneously real-time PCR was also performed for dermatophytes identification using commercially available real-time PCR kits. RESULTS: Out of 65 collected nail samples, dermatophytes were identified in 58 (89.23%) samples by at least one diagnostic method. KOH-Microscopy was positive in 55 (84.62%) samples while fungal culture and real-time PCR were positive in 8 (12.31%) and 43 (66.15%) samples respectively. Five (7.69%) samples were positive by all three methods. Co-infection of two dermatophytes species was detected in six (9.23%) samples by real-time PCR. CONCLUSIONS: This study concluded that real-time PCR can be used as a diagnostic tool for dermatophyte diagnosis in onychomycosis patients and has a greater advantage as it offers lesser turnaround time and edge of species identification. Combining real-time PCR and fungal culture method provides best algorithm for detection of dermatophytes in onychomycosis patients.