ITS-RFLP optimization for dermatophyte identification from clinical sources in Alagoas (Brazil) versus phenotypic...

Area of Science:

• Medical Mycology
• Molecular Biology
• Clinical Diagnostics

Background:

• Dermatophytoses are superficial fungal infections requiring accurate etiological agent identification.
• Traditional identification methods (culture, microscopy) are slow and expertise-dependent.
• Molecular techniques offer potential for rapid and reliable dermatophyte identification.

Purpose of the Study:

• To identify dermatophytes from patients in Alagoas state.
• To compare phenotypical and molecular identification methods.
• To evaluate the efficiency of ITS-RFLP for dermatophyte identification.

Main Methods:

• Clinical samples were cultured on Sabouraud dextrose agar.
• DNA extraction followed by ITS amplicon analysis.
• Restriction Fragment Length Polymorphism (RFLP) using DdeI enzyme (ITS-RFLP).

Main Results:

• ITS-RFLP with DdeI successfully identified Microsporum canis, Nannizzia gypsea, and Trichophyton rubrum.
• The T. tonsurans/T. mentagrophytes complex showed identical restriction patterns.
• Genotyping reclassified two T. tonsurans and one Microsporum sp. strain as T. rubrum.

Conclusions:

• ITS-RFLP with DdeI provides faster and reliable dermatophyte identification compared to traditional methods.
• This molecular method is less efficient for distinguishing closely related cryptic dermatophyte species.
• Further refinement of molecular techniques may be needed for complex cases.