Molecular identification of subtilisin genes (SUB3 and SUB6) in Epidermophyton floccosum

Epidermophyton floccosum is one of the worldwide anthropophilic dermatophytes that invade keratinized structures such as hair, skin, and nail, causing dermatophytosis by secreting important proteases such as subtilisin. This study aimed to evaluate the presence of SUB3 and SUB6 encoding serine proteases in the isolate, which received from the fungi culture collection of Tehran University of Medical Sciences, Faculty of Public Health. Special primers designed according to the highly conserved regions of similar genes in other dermatophytes. Genomic DNA and designed primers used in PCR, then PCR products sequenced with ABI PRISM®3730XL automated Sanger sequencer, and presence of 2 new subtilisin genes (SUB3 and SUB6) were confirmed and recorded in NCBI(with the accession numbers MN206114, MN177931 respectively). The coding sequence of SUB3 found to contain 861 nucleotides, which encodes a polypeptide with 287 amino acids. The coding sequence of SUB6 found to contain 699 nucleotides that encode a polypeptide with 233amino acids. Comparing the sequences with Gene Bank database information, revealed significant homology with other dermatophytes. Achieving a better understanding of the molecular characteristics of virulence genes may help develop effective therapies and prevention strategies.