Separation of Epidermis from Dermis by Filtrates of Trichophyton mentagrophytes

Abstract

ALTHOUGH fungi of the Trichophyton group have been shown to be capable of digesting keratin¹, little attention has been given to the possibility of their liberating toxic substances. As early as 1896, Macfadyen² showed that cultures of T. tonsurans liquefied gelatin by means of a diffusible enzyme, but this appears to have been overlooked in subsequent consideration of the pathology of dermatophytes. As part of an investigation into the pathogenicity of dermatophytes, studies have been made of the effects of filtrates of T. mentagrophytes upon skin. The fungus has been cultured upon a simple fluid medium which will also support the respiration of skin and exercise no toxic effects when portions of skin are ‘cultured’ in it for a period of five hours. The culture medium consisted of 12.9 ml. Krebs–Ringer phosphate, 1 ml. 10 per cent glucose, 1 ml. 2 per cent glycine, 1 ml. 1 per cent ammonium chloride and 0.05 ml. of a mixture of zinc sulphate, manganese sulphate and ferrous sulphate, each 1 mgm./ml. The constituent fluids were sterilized separately and mixed when cold. This amount of medium formed a shallow layer in a 20-fl. oz. screw-capped bottle laid flat.