Document Type: Original Articles
Department of Pathobiology, Faculty of Veterinary Specialized Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Mycology and Parasitology , Faculty of Public Health,Tehran University of Medical Sciences, Tehran, Iran
Research on dermatophytes virulence genes, that cause diseases, is one of the recent years’ researches, that’s why the gene library of this group of microorganism is not so rich. Dermatophytes have the ability to grow exclusively in the skin, hair and nail of human and animals to digest component of the cornified cell envelopment. Although the role of SUB gene in adherence and inflammation steps of infection should be more studied, pathogenic fungi, belong to S8A subfamily, can produce serine proteases as their virulence factors. Some studies demonstrated low enzyme activity of subtilisin-like protease in M.gypseum isolates. Muhsin et al.( 2001 ) revealed the elastinolytic activity in M.gypseum and T.verrucosum. Keratinolytic activities of dermatophyte species are accompanied with secresion of enzymes like serine proteases that are coded by subtilisin genes(SUB). The aim of this study was to determine the presence/absence of SUB genes in clinical and nonclinical samples of Tricophyton verrucosum and Microsporom gypseum. Isolation were identified by direct and laboratory examination; then, for determining the presence of SUB gene, PCR with specific primers was done. Frequencies of SUB gene in almost 66% of isolates was observed. Statistical analysis showed the significant relationship between the presence of SUB gene and each dermatophytes, origin of isolates( human, animals or soil) and the type(hair, skin) of infection(P< 0.005).
This is the first study of the presence / absence of SUB gene in clinical and nonclinical isolates of T. verrucosum and M. gypseum in Iran which may be a new step to further studies.