Lipid composition of Paracoccidioides brasiliensis: possible correlation with virulence of different strains.

The lipid content and composition of four strains of Paracoccidioides brasiliensis were analysed to determine any possible correlation with their virulence for hamsters and mice. Two strains, Pb168 and Pb141, were equal in virulence, Pb9 was slightly virulent and Pb140 was avirulent under the experimental conditions. No correlation was observed between virulence and the total lipid or phospholipid content of the strains. The lipid yield was highest in Pb9 and lowest in Pb168. Polar lipids were highest in Pb9 and least in Pb140. Phosphatidylcholine was the dominant phospholipid in all strains but its percentage was lower in the avirulent strain Pb140. Diphosphatidylglycerol, the least saturated lipid in all strains, was less abundant in Pb140 than in the virulent strains Pb168 and Pb141. In all four strains, neutral lipids constituted the major fraction of total lipids and triglycerides were the predominant individual lipid class, being more abundant in the avirulent and slightly virulent strains that in the virulent strains. The fatty acid profiles of total lipids and individual lipid classes of neutral and polar lipids obtained from the four strains were similar; however, the individual lipid classes showed patterns of preferential distribution of these fatty acids.