THE PROTEOLYTIC ACTIVITY OF STRAINS OF T-MENTAGROPHYTES AND T-RUBRUM ISOLATED FROM TINEA-PEDIS AND TINEA UNGUIUM INFECTIONS

To understand the significance of proteolytic enzymes in the pathogene sis of dermatophyte infections, we have studied the expression of prot eolytic activity in vitro. Cultures were extracted after 1, 2, 3, 4 an d 5 weeks of, growth and the proteolytic activity measured by a peptid e release assay using human stratum corneum as a substrate. Maximum ac tivity was noted at 3 weeks which corresponded to the dissolution of t he stratum corneum particles. Isolates of Trichophyton mentagrophytes and Trichophyton rubrum from 42 patients with tinea pedis or tinea ung uium were established on 2% glucose peptone plates. Using the peptide release assay it was found that after 3 weeks culture, T. mentagrophyt es showed higher activity that. rubrum in tinea pedis (2044 +/- 1067 m u g protein released h(-1) mg(-1) n = 13 compared to 828 +/- 614 mu g protein released h(-1) mg(-1), n = 13). In tinea unguium, the values a t 3 weeks were generally lower. Trichophyton mentagrophytes activity w as 837 +/- 121 mu g protein released h(-1) mg(-1) (n = 3) compared to 470 +/- 271 mu g protein released h(-1) mg(-1) (n = 13) for T. rubrum. Thus, as well as a variation in activity between the two species, the re appears to be a variation in site in terms of expression of activit y.