The erythrasma microorganism in situ: studies using the skin surface biopsy technique.

The skin surface biopsy technique has been used to investigate the erythrasma organism in situ in the stratum corneum in 11 patients. Staining by PAS and Gram stain showed the presence of a large number of organisms arranged haphazardly in some areas and in microcolonies in others. With the scanning electron microscope it was possible to see that smooth filamentous chains of microorganisms had penetrated horn cells and caused disturbance of the surface structure of these cells.Enzyme histochemical tests showed that the erythrasma microorganism possessed a strong reactivity for NAD diaphorase and other mitochondrial enzymes. The reactivity was focal confirming a complex subcellular organization of organelles. It is suggested that the erythrasma microorganism secretes a mucopolysaccharide sheath in some circumstances.