DERMATOPHYTE GROWTH AND DEGRADATION OF HUMAN STRATUM CORNEUM IN VITRO (PATHOGENESIS OF DERMATOPHYTOSIS).
AbstractBackground: This study was carried out to determine growth of dermatophytes using humanstratum corneum in vitro and the degrading effect of Keratinases (Proteinases) on stratum corneumfor a complete understanding of the host parasite relationship. Method: Trichophyton rubrumisolates derived from patients with tinea cruris infections were obtained from the Department ofMedical Microbiology, University Hospital of Wales, U.K. Human stratum corneum sterilizedwith ethylene oxide was used as a nitrogen source in agar culture medium plates. Result: Fungalgrowth took place in plates which contained human stratum corneum particles while there was nogrowth in the plates without stratum corneum at three weeks after initiation. There was a gradualdisappearance of the particles of stratum corneum from the plates at the end of the third weekConclusion: The growth of organisms in plates with human stratum corneum and theirdisappearance at third week suggested that stratum corneum was not only source of nutrition forthe dermatophytes, but also the growing fungal mycelia and the proteinases induced by them wereplaying a part in the digestion of granules and thus may have an important role in the pathogenesisof dermatophyte infections.Key-words: Proteinases, Stratum -corneum, Dermatophytes
Hay RJ, Brostoff J. Immune responses in patients with
chronic Trichophyton rubrum infections. Clin Exp Dermatol
Baxter M, Mann PR. Electron microscopic studies of the
invasion of human hair in vitro by three keratinophilic fungi.
Raubitschek F. Mechanical versus chemical keratolysis by
dermatophytes. Sabouraudia 1961;1: 87-91.
Raubitschek F, Maoz R. Invasion of nails in vitro by certain
dermatophytes. J Invest Dermatol 1957;28: 261-7.
Page RM. Observations on keratin digestion by Microsporum
gypseum. Mycologia 1950;42:591-6026. Kunert J. The digestion of human hair by the dermatophyte
Microsporum gypseum in a submerged culture. Mykosen
Samdani AJ, Dykes PJ, Marks R. The proteolytic activity of
strains of T. mentagrophytes and T. rubrum isolated from tinea
pedis and tinea unguium infections. J Med & Veter Mycol
Tsuboi R, Ko IJ, Matusda K, Ogawa H. A new keratinolytic
proteinase from clinical isolates of Trichophyton
mentagrophytes. J Dermatol 1987; 14: 506-8.
Tsuboi R, Ko IJ, Takamori K, Ogawa H. Isolation of a
keratinolytic proteinas from Trichophyton mentagrophytes
with enzymatic activity at acidic pH. Infect Immun 1989;57:
English MP. The saprophytic growth of keratinophilic fungi
on keratin. Sabouraudia 1963;2:115-30.
Kushwaha RKS. The in vitro degradation of peacock feathers
by some fungi. Mykosen 26:324-6.
Wawrzkiewicz K, Lobarzewski J, Wolski T. Intracellular
keratinase of Trichophyton gallinae. J Med Vet Mycol 1987;