Isolation and molecular identification of dermatophytes and investigation of some environmental factors associated with it

This study aimed to isolate and diagnose dermatophytes by fungal assay methods in the laboratory, identify the species that emerged and compare the current local isolates with those provided by the National Center for Biotechnology Information (NCBI). Dermatophytes are mostly caused by a group of closely related genera of Trichophyton, Microsporum, and Epidermophyton. These groups of fungi invade the stratum corneum of the skin, hair, and nails. Samples were collected from 100 patients infected with dermatophytes at Ibn Al-Atheer Hospital, Mosul-Iraq. A portion of each sample was examined microscopically and the remainder of each sample was cultured on plates of Saboraud Dextrose Agar supplemented with chloramphenic and gentamicin (SDACG). The results showed that among the 100 cases of dermatophytes, only 70 (70%) were positive by direct KOH assay and culture, while false negative results were recorded in 30 (30%) of the samples. Sample culture results showed the identification of six types of dermatophytes. Trichophyton spp and Scopulariopsis brevicaulis, Candida spp showed the highest incidence with 40%, followed by Trichophyton spp with an incidence of 30%, then Scopulariopsis brevicaulis with 20 samples not seen at all, followed by Trichophyton spp with an incidence of 10 %. While the other 20 specimens were never seen, the incidence of fungal infection varied. The most common clinical type was tinea corporis. Men were more affected than women. The results also showed that the age group 6-9 months were more likely to be infected with skin fungi. Dermatophytes isolates were identified by studying the macroscopic and microscopic characteristics of their colonies. To ensure the correctness of their diagnosis, the results obtained using the PCR technique showed that the primers (ITS1, ITS4) amplified the genomes of the fungi examined and the amplified bands ranged from (600 base pairs). The isolates numbered 1.2.3.4 in this study were similar to the isolates. Candida albicans recorded in Genbank numbered OP752127. The isolates numbered 5.6.7.8.9 also showed similarity with the isolates of Candida glabrata recorded in GenBank numbered OP752433. Species numbered 10.11.12 are similar to Candida tropicalis isolates recorded in the GenBank numbered OP712459. Isolates 13.14.15 and 16 show similarity to isolates of Trichophyton mentagrophytes recorded in GenBank OP712621. Isolates 17 and 18 are also similar to Scopulariopsis brevicaulis and are recorded in Genbank OP752128.