Antifungal Activities of Curcuminoids and Difluorinated Curcumin Against Clinical Dermatophyte Isolates.

Dermatophytes are a group of fungal agents that can invade humans' keratinized tissues such as skin, nail, and hair, thereby causing dermatophyte infection (dermatophytosis) or ringworm. Some natural products have been reported to possess fungicidal effects. Hence, the present study investigated the effect of curcuminoids (CUR) and difluorinated curcumin (CDF) against clinical isolates of dermatophytes. CUR and CDF powders were evaluated against dermatophyte species including Trichophyton tonsurans (n = 21), T. mentagrophytes (n = 19), T. interdigitale (n = 18), Microsporum canis (n = 4), T. benhamiae (n = 1), and T. verrucosum (n = 1), based on the CLSI M38-A2 guideline. The minimum inhibitory concentration (MIC) ranges of CUR were 4-16, 8-16, 4-16, 8, 8, and 16 µg/ml for T. tonsurans, T. mentagrophytes, T. interdigitale, M. canis, T. benhamiae, and T. verrucosum, respectively. In addition, MIC ranges of CDF were obtained as 2-32, 4-16, 0.125-16, 8-16, 8, and 16 µg/ml, for T. tonsurans, T. mentagrophytes, T. interdigitale, M. canis, T. benhamiae, and T. verrucosum, respectively. CUR and CDF showed an inhibitory effect against dermatophyte isolates. CDF showed a stronger effect than CUR, especially against T. interdigitale. CUR and CDF have the capacity to be developed for use in dermatophytosis to augment existing preventative/therapeutic strategies.

Low in vitro activity of sertaconazole against clinical isolates of dermatophyte.

BACKGROUND AND PURPOSE: Dermatophytes are a group of fungi specialized in invading humans and other vertebrate keratinized tissues. These fungi cause a variety of skin, nail, and hair disorders, called dermatophytosis (tinea). In some cases, drug resistance to antifungals necessitates special treatment. Among the antifungal agents, sertaconazole (i.e., a third-generation imidazole) has a broad-spectrum against dermatophyte species. Regarding this, the present study was conducted to investigate the antifungal susceptibility of dermatophytes obtained from patients with dermatophytosis in Mashhad located in northeastern Iran. MATERIALS AND METHODS: A total of 75 clinical dermatophyte isolates, including Trichophyton mentagrophytes (n=21), T. interdigital (n=18), T. tonsurans (n=16), Epidermophyton floccosum (n=11), Microsporum canis (n=5), Nannizzia fulvum (n=2), T. benhamiae (n=1), and T. verrucosum (n=1), were evaluated against five antifungal agents of sertaconazole, itraconazole, clotrimazole, terbinafine, and griseofulvin based on the CLSI M38-A2 guideline. RESULTS: According to the results, the minimum inhibitory concentration (MIC) ranges of sertaconazole, terbinafine, griseofulvin, itraconazole, and clotrimazole were estimated at 0.125-16, 0.002-1, 0.5-4, 0.031-4, and 0.016-4 µg/ml, respectively, for dermatophyte species. In addition, the geometric mean (GM) values of the MIC of sertaconazole, terbinafine, griseofulvin, itraconazole, and clotrimazole were obtained as 3.39, 1, 1.44, 1.52, and 1.93, respectively. CONCLUSION: Among the tested antifungals, terbinafine and griseofulvin were the most effective agents against dermatophyte isolates. However, sertaconazole, a third-generation imidazole, did not show any significant effect. Furthermore, M. canis and E. floccosum showed the best response to the antifungal agents.