Resumo

Dermatophytes are highly specialized pathogenic fungi being the most common causative agents of superficial mycoses. These fungi are classified in three genera, Epidermophyton, Microsporum, and Trichophyton, and based on their natural habitats, are classified as geophilic, zoophilic, and anthropophilic species. They have the capacity to invade keratinized tissues (skin, hair, and nails) of humans and animals causing infections named dermatophytosis. These fungi are closely related, being distinguished from each other only by small differences in gene content and genome organization. Because of the severity and longevity of the diseases caused by dermatophytes and its refractoriness, aspects involved in the resistance to antifungals and survival in the host environment are gaining importance. During growth in the presence of four non-structurally related drugs, Amphotericin B, Griseofulvin, Itraconazole, and Terbinafine, we evaluated the expression levels of three genes encoding ATP-binding cassette (ABC) transporters, associated with the efflux of cytotoxic compounds contributing to antifungal drug resistance, mdr1, mdr2, and mdr4, in three species of the Trichophyton genera (T. rubrum, T. equinum, and T. tonsurans). Our analyses suggest the participation of these genes in the toxicant efflux system, with significant upregulated levels of mdr4 in all dermatophytes, indicating the effective participation of this gene in the extrusion system. The response to the presence of Amphotericin B, drug not usually utilized in dermatophytosis treatment, suggests its potential utilization in the treatment of dermatophyte infections. The transcriptional profiles indicate that these three genes could be involved in the antimicrobial treatments failure, being possibly considered potential antifungal drug targets.