KERATINASE ENZYME: VIRULENCE FACTOR IN PATHOGENITY OF DERMATOPHYTES

Abstract

Pathogenic dermatophytes are prevalent causes of a superficial cutaneous infection, which have the ability to invade keratinized structures such as skin, hairs and nails. Dermatophytes infection in the host involves three main steps: adherence to the host tissue, invading, and the development of a host response. In the first stage of infection, dermatophytes adhere to the surface of the keratinized tissue to reach the epidermis by using some factors that mediate adherence of dermatophytes. Various virulence factors are secreted from dermatophytes during the invading process in order to penetrate the host tissue, to obtain nutrients and survive. The aim of this study was to select keratin degrading fungi isolated from from clinical samples of patients with dermatophytosis. Application of soluble preparation of keratin (KS) of chicken feathers enables a preliminary evaluation of the growth of the fungi and screening of fungal isolates that possesed keratinolytic activity and keratinase enzyme. Five dermatophytes i.e. T.rubrum, T.mentagrophytes, M.gypseum, M.canis and C.tropicum were used in our study for keratinase activity. Out of five dermatophytes species studied, all tested fungal species showed a keratinase activity except one species i.e. M.canis. From our findings, these results provide a scientific validation that dermatophytes have keratinase enzyme activity and responsible for virulence factor in pathogenicity of dermatophytes.