Rapid detection of trichophyton rubrum in clinical samples from tinea unguium using PCR

ABSTRACT

Dermatophytosis is one of the most common pandemic fungal infections that is a major health problem in cities and villages. This study aims to evaluate PCR sensitivity and accuracy in the detection of nail dermatophytosis compared to conventional direct and culture detection methods, and performs an assessment of Trichophyton rubrum in patients suspected of having nail dermatophytosis. This experiment was a descriptive-experimental study carried out on 71 nail samples obtained from patients with suspected nail dermatophytosis. All clinical samples of nails or chips were divided into three sections and each section underwent direct examination, culture and molecular tests. In the molecular test, we used fungal rRNA universal primers [ITS1 and ITS4] and Trichophyton rubrum-specific primers. In this study, for the first time in Iran and based on a modified protocol, DNA was directly extracted from tissues of infected nails in less than five hours. Additionally a comparison of the results obtained from routine laboratory methods such as direct examination and culture with PCR verified the high sensitivity and accuracy of PCR compared to the other studied methods. PCR, as a rapid, accurate method, can be a good replacement for conventional culture and direct examination