Multidrug-resistant keratinolytic dermatophytes and non-dermatophytes causing onychomycosis in outpatients.

Aims: This study identified and determined antibiograms of keratinolytic dermatophytes (DM), non-dermatophytic molds (NDM), and yeasts causing onychomycosis.
Methods: Morphological, cultural, and biochemical characteristics were used to identify DM and NDM. The keratinolytic activity (KA) and antibiograms were conducted with keratin azure and the agar diffusion method, respectively. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined using the microdilution method.
Results: Onychomycosis was more prevalent in males (53%) than females, toenails (57%) than fingernails, and commercial employees (40%) than other employees or unemployed. Fungal growth was observed in 92.5% nail samples. DM, NDM, and yeasts caused 46%, 35%, and 19% onychomycosis, respectively. Trichophyton rubrum and Trichophyton mentagrophytes were the common DM. Five different genus of NDM and three different yeasts were isolated. The KA of DM was 30-45% higher than that of NDM and yeasts. All fungal isolates (FI) were resistant to griseofulvin and fluconazole. However, 71%, 64%, and 36% of FI were sensitive to terbinafine hydrochloride, nystatin, and ketoconazole, respectively, while 84% of DM and 46% of NDM were multidrug-resistant. The MIC and MFC of these antifungals against FI ranged from micrograms to milligrams.
Conclusion: Multidrug resistance is growing in keratinolytic DM and NDM.