Microscopic studies of Candida albicans and Torulopsis glabrata after in vitro treatment with bifonazole. Freeze fracture electron microscopy.

1-[(4-Biphenylyl)-phenylmethyl]-1H-imidazole (bifonazole, Bay h 4502, Mycospor) induced profound ultrastructural alterations in Candida albicans and Torulopsis glabrata as observed by freeze fracture electron microscopy. These alterations were characterized by (1) deformation and decrease in number of invaginations in the protoplasmic fracture face and corresponding ridges on the exoplasmic fracture face, and (2) separation of the plasma membrane from the cell wall, leaving a gap which frequently contained small vesicles. Moreover, parts of the inner half of the plasma membrane of C. albicans cells had been torn off and adhered to the exoplasmic fracture face. Cross-fractures of bifonazole-treated cells of C. albicans showed swollen mitochondria and deposition of lipid granules.