Subtilisin Genes (SUB۱-۳) Presence in Microsporum canis Isolates with Human and Animal Source

Background: The presence of subtilisin genes (SUBs) coding for serine proteases in Microsporum canis DNA, contribute to the adherence of fungi to keratinized tissues. The aim of this study was identifed the presence/absence of subtilisin gene family in M.canis isolated from human and animal source. Materials and Methods: This cross-sectional study was performed on ۲۴ samples of patients and pets with dermatophytosis from September to November ۲۰۱۷. Genomic DNA, pertaining to all pure colonies in Sabouraud agar with cycloheximide and chloramphenicol (SCC) and Sabouraud Dextrose agar(SDA), extracted, using rapid method without liquid nitrogen. M. canis were detected by molecular test. SUB۱, SUB۲ and SUB۳ gene of M. canis amplified. The relative frequency of the genomic sequences also calculated. Results: M. canis DNA were extracted from cats (n=۶), dog (n=۱) and human (n=۳) with tinea corporis and showed a high percentage for SUB۲ (۹۰%; ۹/۱۰) and the absence of SUB genes in a M. canis isolated from dog with develop dermatophytosis. The same results were observed in the frequency of the SUBs presence from the colonies grown on SCC and SDA. Conclusion: The presence of SUBs in M. canis isolates with human and animal source will be the basal to understand  zoonotic infections . The absence SUBs in clinical isolate, indicates that they are indispensable for initiation of the infection.