Freeze-fracture studies of the plasmalemma of Candida albicans after treatment with econazole-nitrate.

In electron microscopic studies the interior of the plasmalemma of Candida albicans was revealed by means of the freeze-fracture technique. The superficial structures of the extracellular (E) and protoplasmic (P) fracture faces differed negligibly from structures on the corresponding fracture faces of Saccharomyces cerevisiae. Following treatment with 2.2 x 10(-5) M econazole nitrate a layer, present on the P face in the form of a tight matrix of globular proteins, dissolved into isolated groups of particles whose globular elements sometimes formed hexagonal patterns. As the damage progressed, fissure-shaped membrane invaginations on the P face disappeared. Parts of the outer lipid layer of the plasmalemma were torn off the cell wall and adhered in fragments to the P face. The ultrastructural changes in the plasmalemma induced by econazole nitrate temporally correlate with an increase in the permeability of the cell envelope found in physiological studies performed by other authors.