Identification of Trichophyton Species with Arbitrarily Primed Polymerase Chain Reaction

Abstract

Background and Purpose: Dermatophytes represent a clinically significant group of filamentous fungi characterized by their unique ability to metabolize keratin, the primary protein component of skin, hair, and nails. Conventional diagnostic approaches for identifying these fungi primarily rely on phenotypic characterization through microscopic examination and culture-based techniques. The current investigation addresses the inherent limitations of these traditional methods by implementing a molecular diagnostic approach. Materials and Methods: The current study employed arbitrarily primed polymerase chain reaction (AP-PCR) for the specific detection and differentiation of four prevalent dermatophyte species: Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans, and Trichophyton verrucosum. Genomic DNA from these species was amplified using four distinct arbitrary primers: OPAA11 (5’ ACCCGACCTG 3’), OPU15 (5’ ACGGGCCAGT 3’), OPAA17 (5’ GAGCCCG ACT 3’), and OPD18 (5’ GAGAGCCAAC 3’). Results: In this study of 272 cutaneous dermatophyte infections, Trichophyton was the predominant genus. T. mentagrophytes was the most frequent species, accounting for 115 (42.2%) of cases, with a near-even gender distribution. It was primarily associated with Tinea corporis and Tinea cruris. T. rubrum was the second most common species (66 cases, 24.2%), showing a male predominance and high association with Tinea cruris. Final species identification utilized AP-PCR and ITS sequencing, which also revealed the presence of T. interdigitale strains. Conclusion: AP-PCR offers a rapid, reliable, sensitive, and discriminatory molecular approach for accurate dermatophyte identification, overcoming the consistency and specificity limitations of conventional phenotypic methods.