Identification of Candida isolates from onychomycosis by mycological and molecular methods

Onychomycosis is a common fungal infection affecting nails that cause by different kind of fungi such as dermatophytes, yeasts and non-dermatophytes mold. In this study we applied Seminested PCR for detection of Candida in nail specimens. 30 nail samples in which were infected by Candida species from culture-proven were supplied. All yeasts were identified by germ tube test, chlamydospor production on cornmeal agar and using CHROM agar Candida medium. DNA was extracted by boiling technique. The universal outer primers (CTSF & CTSR) amplified the Internal Transcribed Spacer2 (ITS2). The species-specific primers (CADET, CPDET, CTDET, CGDET and CDDET), complementary to unique sequences within the ITS2 of each test species, amplified species-specific DNA in the reamplification step of snPCR. PCR products were identified by electrophoresis. 30 Candida species were detected and identified by using snPCR. The results of snPCR in Candida species identification were consisting of: 12 cases of C. albicans, 8 cases of C. parapsilosis, 6 cases C. tropicalis, 4 cases of C. glabrata. C. dubliniensis wasn’t detected in nail samples. The Seminested PCR that was applied and evaluated in this study is a specific and sensitive method for the diagnosis of Candidal onychomycosis caused by common pathogenic Candida species i.e., C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata. Besides the snPCR has the added advantage of identifying Candida species in patients being rapid.