Intercellular matrix in colonies of Candida.

The histochemistry and fine structure of typical colonies of six species of Candida were studied, using a total of 31 clinical isolates. The colonies consisted of viable and degenerate cells which lay in an intercellular matrix. This matrix was made up of amorphous, granular, and fibrillar components, the relative proportions and total amount of which varied from species to species. The cells of all species were surrounded by a zone of homogeneous amorphus material, which may be a highly cross-linked carbohydrate. This separated intact cells from irregularly distributed granular debris derived from the cytoplasm of degenerate cells. Focal cellular degeneration and associated granular debris were present within the colonies of all species and were most common in the surface layers of cells of colonies of C. albicans and C. tropicalis. The large amounts of intercellular matrix in this region formed a surface coat on colonies of these two species. Intercellular strands of cell wall material, and to a lesser extent other membranous elements from degenerate cells, formed a prominent fibrillar meshwork in the colonies of C. albicans and C. tropicalis, but were less common in those of C. pseudotropicalis and C. guilliermondii and seldom seen in those of C. parapsilosis and C. krusei.