Cytology of Candida Albicans as Influenced by Drugs Acting on the Cytoplasmic Membrane.

Gale, Glen R. (Veterans Administration Hospital, Durham, N.C.) Cytology of Candida albicans as influenced by drugs acting on the cytoplasmic membrane. J. Bacteriol. 86:151-157. 1963.-An electron microscopic comparison was made of the cytological responses of Candida albicans to benzalkonium chloride, amphotericin B, and filipin, all of which are thought to exert their primary pharmacological actions on the cytoplasmic membrane of susceptible microorganisms. After 5 to 15 min of exposure to benzalkonium chloride, most of the cytoplasm became less dense, and intact nuclei, mitochondria, or intracytoplasmic membranes were not observed. The remaining dense cytoplasm contained numerous small holes. The polyene antifungal agents, amphotericin B and filipin, caused a reduction in cytoplasmic density, but had no observable effect on nuclei or mitochondria. The intervals before onset of changes induced by the polyene agents correlated with the known time-dependent binding of these drugs by cells, and the decreased electron scattering induced by all three agents was compatible with their known abilities to cause a loss of integrity of the cytoplasmic membrane with resultant leakage of cytoplasmic components. No consistent morphological effect of any of these drugs on the cytoplasmic membrane could be shown.