Analysis of extracellular enzymatic activity of fungi isolated from patients with onychomycosis

Abstract

Objective To determine the extracellular enzymatic activity of common pathogens for onychomycosis, in the hope of finding virulence factors associated with the pathogenesis of onychomycosis. Methods Strains tested in this study included standard strains of common dermatophyte and non-dermatophyte fungi as well as clinical isolates of Trichophyton rubrum from patients with onychomycosis. All the tested strains were cultured in medium containing nail fragments at 25 ℃ for 10 to 21 days followed by the determination of the nail fragment-containing medium, a significant increase was observed in the activities of esterase, esterase lipase, N-acetyl-β-glucosaminidase and α-mannosidase in dermatophytes compared with non-dermatophytes (all P ＜ 0.05 ), as well as in the activity of N-acetyl-β-glucosaminidase in Trichophyton rubrum compared with the other tested species of fungi (all P ＜ 0.05). No significant difference was noted in the activity of extracellular enzymes, except for that of naphthol-AS-BI-phosphohydrolase, between the isolates of Trichophyton rubrum from patients with different ranges of scoring clinical index for onychomycosis (SCIO). Conclusions In specific conditions, the extracellular enzymatic activity of fungi isolated from patients with onychomycosis is associated with fungal species, and may have a certain influence on the manifestations of anychomycosis. Key words: Onychomycosis; Hydrolases; Virulence factors