Translation elongation factor 1-alpha gene as a marker for diagnosing of candidal onychomycosis.

BACKGROUND AND PURPOSE

Culture-based identification methods have been the gold standard for the diagnosis of candidal onychomycosis. Molecular technologies, such as polymerase chain reaction (PCR) assays, can provide an alternative for the rapid detection of species. The present study was conducted to investigate a pan- PCR assay based on the translation elongation factor 1-alpha () gene for the detection of the most prevalent pathogenic species.

MATERIALS AND METHODS

For the purpose of the study, an optimized pan- PCR primer pair was designed, and the target was amplified and sequenced. The analytical and clinical diagnostic performance of the designed primers was tested using 17 reference strains, 137 nail scrapings suspected of onychomycosis, and 10 healthy nail specimens.

RESULTS

The use of the universal primers designed on gene resulted in the successful amplification of a 270-base pair fragment in all species tested, except for and reacted neither with other fungi nor with . The sequence difference count matrix showed poor insertion/deletion differences (0-2 nt) among species. Among 137 nail specimens, 35% (n=48), 30.7% (n=42), and 40.1% (n=55) of the samples were found to be positive by direct microscopy, culture, and pan- PCR, respectively.

CONCLUSION

Based on the findings, the PCR-based detection targeting the DNA gene is a rapid and simple procedure for the diagnosis of candidal onychomycosis directly from nail sample.