[Ultrastructure of parasitic forms of the agent of coccidioidomycosis].

The authors studied the ultrastructure of the Coccidiodes immitis spherules in the sections of the abdominal cavity foci and pneumonic foci of Cricetus auratus W. and in albino mice infected intraperitoneally with a lethal dose of the mycelium fungus phase. It was found that the spherules of coccidiod fungus represented multinuclear cells with a well-organized protoplast included into a complicated supermembrane structure--the cell wall. Endospores (which copied the spherule structure in miniature) formed as a result of division of the cytoplasm by entire sections into polygonal segments with the subsequent separation of the latter. Due to the rupture of the cell wall of mature sporulating spherules the endospores are released into the surrounding tissue and are attacked there and phagocytized by polynuclears and macrophages. Phygocytosis of the fungi is mostly incomplete.