Utilities of tripsin and trypan blue for diagnosis of dermatophytes

Abstract

Introduction: Dermatophytes are group of keratinophilic fungi invading keratinized tissues of skin and its appendages. Althugh it is not a life threatening condition, the lesions may spread in size and are associated with significant negative cosmetic, social, psychological impact leading to adverse effects on the way of life. Although diagnosis of dermatophytosis is essentially clinical, laboratory methods will help to confirm the diagnosis and appropriate treatment of the disease. Early diagnosis and treatment of index case within family and/or community will reduce spread of dermatophytic infections. Aim and Objectives: Detect dermatophytes infection by microscopic examination using 10% KOH (Potassium Hydroxide) as well as Neutral Red, to isolate dermatophyte on Sabourard's Dextrose agar with or without treatment with trypsin and to compare the effect of trypsin on isolation of dermatophytes. Materials and Methods: Prospective cross sectional, laboratory-based study conducted at a tertiary care centre. A total of 60 samples were included in the study. Microscopical examination followed by culture was done for all the samples. The sample was divided into two parts out of which one was treated with trypsin and other without trypsin. Both parts were further processed by the standard mycological protocol. We also used neutral red to assess the viability of fungal pathogen. Results: The study consisted of 40 (66.66 %) male patients and 20 (33.33 %) female patients.The mean age of the study population was 34.97 + 19.03 yrs.Majority of samples were for nail diseases, 83.33% Dermatophytes were visualized by direct microscopy with KOH mount in 12 (20%) cases. The neutral red staining after trypsonization yields positive result in 26 (43.33%) cases. The dermatophytes were cultured on SDA with and without trypsin treatment of the specimens. The growth was observed in 26 (43.33%) cases and 24 (40%) cases respectively. Culture positive growth (40 %) cases while KOH positivity was observed in 20% samples. Conclusion: Trypsinization improves fungus culture. However use of Neutral red and Trypsinization helped in achieving better results as compared to conventional methods.