Morphological and Molecular Identification of Dermatophytes Isolated from Clinical Samples Using ITS rDNA Sequencing

Dermatophytes Isolated

Abstract

Background: Dermatophytes are the principal causative agents of superficial fungal infections and remain an important public health concern. Accurate species identification is essential for epidemiological characterization. Aim: The present study aimed to isolate and identify dermatophytes recovered from patients with suspected dermatophytosis using conventional morphological and molecular techniques. Methodology: A total of 80 clinical specimens were collected and cultured on Sabouraud Dextrose Agar (SDA). The recovered isolates were identified based on their macroscopic and microscopic characteristics, followed by molecular confirmation through amplification and sequencing of the internal transcribed spacer (ITS) region. Results: Phylogenetic analysis was performed to determine the genetic relationships among the representative isolates and reference strains. Seventy fungal isolates (87.5%) were recovered, of which dermatophytes accounted for 92.9%. Trichophyton indotineae was the predominant species (57.1%), followed by Microsporum canis (35.7%), while Chaetomium globosum represented 7.1% of the isolates. The morphological characteristics of T. indotineae and M. canis were consistent with their classical taxonomic descriptions. Molecular analysis confirmed species identification, with ITS sequences showing more than 99% similarity to reference strains deposited in GenBank. Conclusions: Phylogenetic analysis demonstrated that the representative Iraqi isolates clustered closely with international strains, indicating limited genetic diversity. These findings demonstrate that the integration of conventional morphological examination with ITS-based molecular identification provides a reliable approach for the accurate identification and epidemiological characterization of dermatophytes.