The lipid composition and permeability to the triazole antifungal antibiotic ICI 153066 of serum-grown mycelial cultures of Candida albicans.
The total lipid content of Candida albicans (serotype A: NCPF 3153) exponential-phase mycelial cultures grown in tissue-culture medium 199 (containing 10%, v/v, foetal calf serum) was 29.8 +/- 8 mg (g dry weight)-1 (mean +/- SD). The weight ratios of phospholipid to neutral lipid and phospholipid to non-esterified sterol were 2.6 +/- 0.4 and 24.9 +/- 0.5, respectively. The major phospholipid was phosphatidylcholine with smaller amounts of phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylglycerol and diphosphatidylglycerol; the most abundant fatty acids were palmitic, palmitoleic, oleic and linoleic acids. The major neutral lipids comprised esterified sterol, triacylglycerol and non-esterified fatty acid with a smaller amount of non-esterified sterol. The fatty acid compositions of the three fatty-acid-containing neutral lipids were distinct from each other and the phospholipids. Comparison with previous data on yeast cultures of C. albicans A grown in glucose broth shows that mycelial cultures have a larger lipid content, lower phospholipid to neutral lipid ratio and higher phospholipid to non-esterified sterol ratio. We now show that mycelial cultures were more permeable to a [14C]triazole antifungal antibiotic compared with exponentially growing yeast cultures of several azole-sensitive strains. Taken together these data are consistent with there being a relationship between the phospholipid/non-esterified sterol ratio of a culture and its ability to accumulate a triazole.
Hitchcock
C A
CA
Department of Biochemistry, University of Wales College of Cardiff, UK.
Barrett-Bee
K J
KJ
Russell
N J
NJ
D000935:Antifungal Agents / Q000378:metabolism*; D002176:Candida albicans / Q000254:growth & development / Q000378:metabolism*; D002463:Cell Membrane Permeability; D003470:Culture Media / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D008055:Lipids / Q000032:analysis*; D008563:Membrane Lipids / Q000032:analysis; D008828:Microbiological Techniques; D010743:Phospholipids / Q000032:analysis; D013261:Sterols / Q000032:analysis; D014230:Triazoles / Q000378:metabolism*
D000935:Antifungal Agents; D003470:Culture Media; D005227:Fatty Acids; D008055:Lipids; D008563:Membrane Lipids; D010743:Phospholipids; D013261:Sterols; D014230:Triazoles; C040032:ICI 153066