Molecular cloning and characterization of a novel ABC transporter gene in the human pathogen Trichophyton rubrum.

A gene encoding an ABC transporter in the dermatophyte Trichophyton rubrum, TruMDR1, was cloned by PCR using degenerate primers. The open reading frame of TruMDR1 is 4838 bp long and the deduced amino acid sequence shows high homology with ABC transporters involved in drug efflux of other fungi. The effect of chemicals on the expression level of mRNAs of this gene was analysed by Northern blot. An increase in expression level was observed when the fungus was exposed to ethidium bromide, ketoconazole, cycloheximide, fluconazole, griseofulvin, imazalil and itraconazole, suggesting the participation of this gene in drug efflux in this dermatophyte. The identification of a gene potentially involved in cellular detoxification in a pathogenic fungus is the first step towards knowing molecular events related to antifungal resistance.