Enzyme patterns of dermatophytes

Exoenzymes produced by common dermatophytes, in addition to their ability to cause cutaneous inflammation, are thought to contribute to fungal spread. To investigate the patterns of enzymes released by common dermatophytes as well as Scopulariopsis brevicaulis, the fungi were grown in liquid media containing either hair, stratum corneum, neopeptone or lipids, or in RPMI medium. Enzymes recovered from the culture supernatants were compared using the Api-zyme test. As a result, the widest range of enzymes was seen in protein-containing media, with a maximum of 13 enzymes stimulated by growth on hair. Dermatophytes in all protein media produced high levels of alkaline phosphatase, esterases and leucine arylamidase. In these media the highest total enzymatic activity was released by Microsporum canis, whereas the lowest was released by Epidermophyton floccosum. Although RPMI broth stimulated luxuriant growth of all species, recovery was limited to a maximum of six enzymes. In lipid medium E. floccosum and M. canis failed to grow. When comparing the various nutrients, Scopulariopsis released fewer enzymes than the dermatophytes and only minor quantities of alkaline phosphatase. We conclude that alkaline phosphatase, esterases and leucine arylamidase may be important for the parasitic growth of dermatophytes. The total enzymatic activity of dermatophytes appears to be correlated with the intensity of cutaneous inflammation. Furthermore, enzyme measurements may be helpful for species identification.