Subinhibitory Concentration of Octenidine and Pirtenidine: Influence on the Lipid and Sterol Contents of <i>Candida albicans</i>

Abstract

The effect of subinhibitory concentrations of octenidine and pirtenidine on the lipid and sterol composition of Candida albicans was investigated. The total lipid and sterol contents of C. albicans grown in the presence of either octenidine or pirtenidine were reduced compared with control-grown cells. The major differences in the lipid composition of drug-grown and control cells were phosphatidylglycerol, phosphatidylcholine and monogalactosyldiacylglycerol, which increased in the presence of octenidine and pirtenidine. Lower proportions of phosphatidic acid were found in yeasts grown in the presence of the drugs when compared with control C. albicans. Fatty acid analysis of control-grown cells showed that the major fatty acids were C₁₆ and C₁₈. Drug-grown cells had higher proportions of palmitic and linolenic acids but lower proportion of oleic acid. The C₁₆/C₁₈ ratios were higher for octenidine- and pirtenidine-grown cells than control cells. Differences in the fatty acid composition of major phospholipids and neutral lipids between drug-grown and control yeasts were also observed. Sterol analysis of control-grown cells showed that the major sterol present was ergosterol (65.9%). A significant increase in squalene and 4,14-dimethylzymosterol was observed in pirtenidine-treated cells, while octenidine-treated cells showed an increase in zymosterol and obtusifoliol contents. Our results suggest that octenidine and pirtenidine affect the lipids and sterol of C. albicans in different ways. The implications of these findings on the mode of action of these two drugs is discussed.

Mechanism of Fluconazole Resistance in Candida albicans Biofilms: Phase-Specific Role of Efflux Pumps and Membrane Sterols

“…The cellular target of fluconazole in C. albicans is a cytochrome P-450 hemoprotein involved in the ergosterol biosynthetic pathway (19). Alterations in sterol composition have previously been linked to antifungal resistance in planktonic cells (18,24,47). Since our data showed no role of efflux pumps in the fluconazole resistance of intermediate-and maturephase biofilms, we investigated whether this phenotype can be attributed to changes in sterol composition.…”

Sterol composition of Cryptococcus neoformans in the presence and absence of fluconazole

“…Prior to sterol extraction all cryptococcal strains were grown as a shake culture (200 rpm) in Yeast Nitrogen Base broth with amino acids (Difco, Detroit, Mich.) and enriched with 0.5% (wt/hol) glucose (YNB) at 37°C for 22 to 24 h (late exponential growth phase, corresponding to an optical density at 420 nm of 0.9 for all isolates), ensuring that the observed differences in sterols among the strains were not due to sampling at various stages of growth. Sterols were extracted by the method of Ghannoum et al (6). Briefly, KOH (1.5 g) in 2 ml of distilled water was added to 0.2 g (wet weight) of intact cells, and the volume of the suspension was adjusted to 10 ml by the addition of ethanol.…”

Octenidine Dihydrochloride, a Modern Antiseptic for Skin, Mucous Membranes and Wounds

“…The residual effect of octenidine is remarkable [91,92] . Besides the direct antimycotic effect, octenidine induced changes in the lipid and sterol contents of Candida albicans and is binding to human buccal epithelial cells in vitro [76,93] .…”