ASSAY OF EXTRACELLULAR ENZYMES OF DERMATOPHYTES AND NON-DERMATOPHYTES ISOLATED FROM RICE FARMERS IN EBONYI STATE, NIGERIA

Abstract

Dermatophytes and non-dermatophytes are the major cause of cutaneous mycoses. The infection is highly contagious and represent significant public health problem in Nigeria and the world at large. These groups of fungi invade and grow in dead keratin. They are capable of producing several enzymes for their survival within a wide range of substrates and causing severe reactions. The ability of dermatophyte and nondermatophyte fungal species isolated from rice farmers in parts of Ebonyi State to secrete extracellular enzymes was screened on solid media. This was determined by their ability to develop clear zone formation. Highest keratinase (23 mm), protease (24 mm), lipase (22 mm) and collagenase (17 mm) activities were observed in Trichophyton rubrum while the highest xylanase (17 mm) and cellulase (22 mm) activities were observed in Trichophyton tonsurans and Trichophyton mentagrophytes respectively. Of the nondermatophytes isolated, highest keratinase (15 mm), protease (16 mm), lipase (18 mm), xylanase (11.5 mm)  and cellulase (14 mm) activities were observed in Aspergillus flavus while the highest collagenase (10.5 mm) activity was observed in Aspergillus nomius. The ability of these fungal organisms to produce these enzymes could explain their ability to degrade the keratinized tissues of the skin, hair and nails, indicating the importance of these enzymes in the pathogenesis of cutaneous mycoses.