IN VITRO ANTIFUNGAL SUSCEPTIBILITY OF CLINICAL FUNGAL ISOLATES USING DISK DIFFUSION METHOD
Rania M. Abdel Halim
Clinical Pathology Department-Faculty of Medicine-Ain Shams University
Aim: to determine antifungal susceptibility patterns among clinical fungal isolates using disk diffusion method Methods: Nail specimens (n=114) were collected from 100 cases of onychomycosis including 14 patients showing lesions in both toenails and fingernails. All samples were subjected to KOH plus DMSO mount in addition to fungal culture onto Sabouraud’s dextrose agar with chloramphenicol (SDA+C) and Dermatophyte test media (DTM). Chromogenic Candida Agar (CCA), Bromocresol purple Milk solid glucose agar (BCP) and Potato dextrose agar (PDA) were used for differentiation of Candida, dermatophyte and non-dermatophyte molds species respectively. Antifungal disc diffusion susceptibility testing was performed according to CLSI M44-A2, 2009 for yeasts, CLSI 2010 guidelines for non-dermatophytes molds and Nweze et al. 2010 for dermatophytes Results: Out of all specimens collected, (47.33%) yeast, (50.38%) non-dermatophyte molds, and (2.29%) dermatophytes isolates were recovered. All the tested yeast isolates showed 100% sensitivity to both Itraconazole and Nystatin followed by Voriconazole with 83% sensitivity. Dermatophytes isolates were completely resistant to Fluconazole, 50% sensitive to Itraconazole, Voriconazole and Griseofulvin. Ketoconazole recorded 100% sensitivity among dermatophytes. Non-dermatophyte molds were 100% sensitive to Itraconazole followed by Caspofungin which demonstrated 75% sensitivity. Conclusion: Itraconazole demonstrated the best sensitivity among all of the tested fungal isolates. Antifungal disc diffusion susceptibility testing is simple, economic and easy to perform, and thus it is essential to be performed in routine microbiology laboratory for appropriate treatment of fungal infections.