The proteolytic activity of strains of T. mentagrophytes and T. rubrum isolated from tinea pedis and tinea unguium infections.J Med Vet Mycol. 1995 May-Jun; 33(3):167-70.JM
To understand the significance of proteolytic enzymes in the pathogenesis of dermatophyte infections, we have studied the expression of proteolytic activity in vitro. Cultures were extracted after 1, 2, 3, 4 and 5 weeks of growth and the proteolytic activity measured by a peptide release assay using human stratum corneum as a substrate. Maximum activity was noted at 3 weeks which corresponded to the dissolution of the stratum corneum particles. Isolates of Trichophyton mentagrophytes and Trichophyton rubrum from 42 patients with tinea pedis or tinea unguium were established on 2% glucose peptone plates. Using the peptide release assay it was found that after 3 weeks culture, T. mentagrophytes showed higher activity that T. rubrum in tinea pedis (2044 +/- 1067 micrograms protein released h-1 mg-1, n = 13 compared to 828 +/- 614 micrograms protein released h-1 mg-1, n = 13). In tinea unguium, the values at 3 weeks were generally lower. Trichophyton mentagrophytes activity was 837 +/- 121 micrograms protein released h-1 mg-1 (n = 3) compared to 470 +/- 271 micrograms protein released h-1 mg-1 (n = 13) for T. rubrum. Thus, as well as a variation in activity between the two species, there appears to be a variation in site in terms of expression of activity.