| Abstract: | 250 Candida guilliermondii strains resistant to the polyene antibiotics nystatin, levorin and amphotericin B were obtained using UV irradiation. When the mutant strains became resistant to one of the polyene antibiotics, their resistance to the other ones changed. Phenotypic analysis showed that the resistance of the strains to polyene antibiotics did not make them susceptible to a rise in osmotic pressure and to a change of the temperature of incubation. Some of the polyene-resistant strains were stained in a medium with methylene blue. Analysis of the sterol composition in the mutants by UV spectroscopy showed that the resistance to polyene antibiotics sometimes involved changes in the sterol composition. Two new UV spectrum types were recorded for the sterols of the mutant strains; they differed from the UV spectrum for the sterols of the parent sensitive strain. |
