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- Trichophyton rubrum- 28188, Trichophyton mentagrophytes- 9533, Trichophyton tonsurans- 28942, one CBS KNAW Fungal Biodiversity Centre strain- Arthroderma grubyi- 243.66, five clinical isolates- T. rubrum, T. mentagrophytes, Trichophyton rubrum var. raubitschekii, Trichophyton interdigitale, Epidermophyton floccosum, and two laboratory isolates - Microsporum gypseum and Microsporum canis 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. T. rubrum, T. rubrum ATCC strain, T. rubrum var. raubitschekii, T. mentagrophytes, T. mentagrophytes ATCC strain, T. interdigitale and A. grubyi 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 T. rubrum complex, T. mentagrophytes complex and A. grubyi showed complete haemolysis and hence they may also act as a non-enzymatic virulence marker for dermatophytes.

[1]  A. H. Al-Hamadani,et al.  In vitro, determination of optimal conditions of growth and proteolytic activity of clinical isolates of Trichophyton rubrum , 2015 .

[2]  Dutsadee Chinnapun.  Virulence Factors Involved in Pathogenicity of Dermatophytes , 2015 .

[3]  V. Lakshmi,et al.  Efficient Degradation of Feather by Keratinase Producing Bacillus sp. , 2013, International journal of microbiology.

[4]  S. Chandra,et al.  Difference in keratinase activity of dermatophytes at different environmental conditions is an attribute of adaptation to parasitism , 2012, Mycoses.

[5]  José A. León,et al.  Analytical Methods for Lipases Activity Determination: A Review , 2012 .

[6]  T. C. White,et al.  Dermatophyte Virulence Factors: Identifying and Analyzing Genes That May Contribute to Chronic or Acute Skin Infections , 2011, International journal of microbiology.

[7]  S. Pornsuwan,et al.  Melanogenesis in dermatophyte species in vitro and during infection. , 2011, Microbiology.

[8]  G. R. Naik,et al.  Production and characterization of feather degrading keratinase from Bacillus sp. JB 99 , 2010 .

[9]  Wenjun Li,et al.  Production, characterization and application of keratinase from Streptomyces gulbargensis. , 2009, Bioresource technology.

[10]  P. Schaufuss,et al.  Haemolytic activities of Trichophyton species. , 2003, Medical mycology.

[11]  R. Summerbell,et al.  Detection of xanthomegnin in epidermal materials infected with Trichophyton rubrum. , 2000, The Journal of investigative dermatology.

[12]  A. H. Aubaid,et al.  Extracellular enzyme activities of dermatophytes and yeast isolates on solid media , 1997, Mycoses.

[13]  R. Summerbell,et al.  The dermatophytes , 1995, Clinical microbiology reviews.

[14]  L. Gentry,et al.  Plate method for detection of phospholipase activity in Candida albicans. , 1982, Sabouraudia.

[15]  L. Hellgren,et al.  Lipolytic activity of some dermatophytes. , 1980, Journal of medical microbiology.

[16]  P Hajdú,et al.  [Analytical methods I]. , 1975, Arzneimittel-Forschung.