title: Freeze fracture electron microscopical investigation of Candida albicans cells sensitive and resistant to nystatin.
abstract: A sterol mutant was isolated after nitrosoguanidine treatment, on the basis of th nystatin-resistant phenotypic behaviour, from a Candida albicans strain requiring adenine. The plasma membrane ultrastructure of the resistant mutant, observed by freeze-fracture electron microscopy, was not significantly different from the parental, ergosterol producing nystatin-sensitive strain. Nystatin treatment caused no ultrastructural change in the resistant strain, but led to the aggregation of membrane particles in the sensitive strain: this effect was considered to be the specific effect of nystatin. Other, probably nonspecific effects of nystatin on the sensitive strain were a deepening and deformation of invaginations, atypical membrane fracture, certain changes in the structure of cell wall and special ornamentation of its surface. No change in the intracellular membranes was observed.
mesh_terms: D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000648:ultrastructure; D002462:Cell Membrane / Q000648:ultrastructure; D004352:Drug Resistance, Microbial; D005614:Freeze Fracturing; D009154:Mutation; D009761:Nystatin / Q000494:pharmacology*; D013261:Sterols / Q000235:genetics
chemical_list: D013261:Sterols; D009761:Nystatin