Quantitative assay of dermatophyte-infected guinea pig skin scales

A technique to obtain homogeneous suspensions of fungal particles in scrapings from infected skin was devised that permits delivering uniform inocula to culture media being evaluated for suitability as primary isolation media for dermatophytes. The technique consisted of trypsinization of the scales, utilizing scrapings from lesions experimentally induced with an isolate of Trichophyton mentagrophytes var. granulare on guinea pigs. Optimal conditions for dislodging the fungal particles were assessed by colony counts. One-hour treatments with 0.5% (1:300) trypsin yielded the highest counts.