Enzymatic and Non-Enzymatic Virulence Activities of Dermatophytes on Solid Media.

Introduction: Dermatophytes are keratinophilic fungi causing superficial cutaneous infections that account 20-25% of the global population. As per literature search, there is a dearth in the study on virulence factors of dermatophytes from the Indian sub-continent and moreover the association of the virulence factors and the host tissue in vitro helps in understanding the host-pathogen interaction.

Aim: To analyse the enzymatic and non-enzymatic virulence activities of dermatophytes on solid media.

Materials And Methods: A total of 11 isolates, three standard American Type Culture Collection (ATCC) strains- - 28188, - 9533, - 28942, one CBS KNAW Fungal Biodiversity Centre strain- - 243.66 five clinical isolates- , , var. , , , and two laboratory isolates - and were screened for the production of virulence enzymes such as phospholipase, lipase, protease, gelatinase and non-enzyme virulence factors (haemolytic activity) of dermatophytes. The clinical isolates were identified from a tertiary care hospital, Chennai. These dermatophytes were tested upon specific substrates on solid media such as egg yolk, tween 80, bovine serum albumin, gelatin powder and sheep blood respectively.

Results: The virulence activity of phospholipase, lipase, protease and gelatinase was observed from all the dermatophyte species. , ATCC strain, var. , , ATCC strain, and CBS strain produced complete haemolysis, whereas other dermatophytes showed no haemolytic activity.

Conclusion: Phospholipase, lipase, protease and gelatinase act as enzymatic virulence marker and the complex, complex and showed complete haemolysis and hence they may also act as a non-enzymatic virulence marker for dermatophytes.