Study of lipids in dermatophytes. II. The effect of ketoconazole in the exponential stage of growth.
There was studied the effect of ketoconazole on the growth, the amount of ergosterol and the relative distribution of fatty acids in the sensitive strain MG-155 of M. gypseum and its two ketoconazole-resistant mutants UV-1 and UV-2 (induction by UV radiation) in the exponential stage growth. After three-day cultivation in the medium with ketoconazole (0.64 microgram.ml-1) there appeared 40% inhibition of growth in MG-155, 10% inhibition in UV-2 and only 4% inhibition UV-1. The amount of ergosterol decreased in MG-155, in both mutants the amount of ergosterol increased by the effect of ketoconazole (by more than 50%). The main saturate fatty acids are palmitic acid (10% and stearic acid (4%). The major fraction of unsaturate fatty acids is formed by linoleic acid (50%) and by oleic acid (4%). Ketoconazole does not affect the quality of fatty acids spectre, it changes only the size of the relative distribution of individual fatty acids. In this point of view, the mutant UV-2, and namely the mutant UV-1 (the higher degree of resistance) differ from the initial sensitive strain MG-155. Ketoconazole provokes in mutants a higher reduction of stearic acid fraction, of saturate fatty acids C greater than 18 and of triunsaturate fatty acids and it causes only minimum (4% for UV-1) decrease of oleic acid. The results of cultivations with postponed application of ketoconazole to the medium (on the 2nd the 1st day before the mycelium harvest) show in a decisive way that effect of ketoconazole is fully developed only on condition that ketoconazole is added to the medium simultaneously with the inoculum. There are discussed several conclusions with regard to the findings in the identical strains in stationary stage of growth.
Merkunová
A
A
Department of Physiology, Medical Faculty, Palacký University, Olomouc, Czechoslovakia.
Chmela
Z
Z
Lenhart
K
K
D000818:Animals; D005227:Fatty Acids / Q000378:metabolism*; D007654:Ketoconazole / Q000494:pharmacology*; D016814:Microsporidia / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
D005227:Fatty Acids; D007654:Ketoconazole