Contact sensitizing properties of some fatty acids in dermatophytes

Effect of keratin on the lipid composition of Scopulariopsis brevicaulis (Bainier)

Lipid content and composition of Scopulariopsis brevicaulis cultured with or without its natural substrate keratin was investigated. Lipid content was found to be lower in the presence of keratin (maximum 12% against 19% in the absence of keratin), with differences in levels of linoleic acid (C18 = 2), palmitic (C16:0) and to a lesser extent palmitoleic (C16 = 1) and alpha-linolenic (C18 = 3) acids. The degree of unsaturation was correspondingly lower in the organisms cultured with keratin as substrate.

Lipids of dermatophytes II. Effect of growth condition on the lipid composition and membrane transport of Microsporum gypseum

Supplementation of glucose-containing medium with ethanol and replacement of glucose by glycerol in the Sabouraud's growth medium of Microsporum gypseum altered the levels of total phospholipids as well as their apolar and polar head groups. The levels of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) increased under these growth conditions; also, the ratio of unsaturated/saturated phospholipid fatty acids decreased on ethanol supplementation but increased in the presence of glycerol. Steady state accumulation of labelled amino acids (glycine, lysine and aspartic acid) was affected under these conditions.

Immunochemical studies of conjugates of isomaltosyl oligosaccharides to lipid. I. Antigenicity of the glycolipids and the production of specific antibodies in rabbits

Isomaltose oligosaccharides varying in size from two sugars, isomaltose (IM2), to seven sugars, isomaltohepatose (IM7), were coupled to stearylamine by reductive amination with sodium cyanoborohydride. Each compound was purified by column chromatography to yield a series of glycolipids containing oligosaccharides differing in length. Stearyl-isomaltotriose to stearyl-IM7 could be incorporated into liposomes and could render them agglutinable by specific antibodies to alpha 1 leads to 6 dextran and could be lysed if complement was also added, whereas those containing stearyl-IM2 were not agglutinated or lysed, indicating that stearyl-IM2 may not be protruding from the liposome surface sufficiently to react with the antibody. Stearyl-isomaltosyl oligosaccharides by themselves or incorporated into liposomes were equally antigenic when emulsified in complete Freund's adjuvant. They elicited pauciclonal responses, and the antibodies were alpha 1 leads to 6 specific, cross-reacted with dextran, and gave semirestricted isoelectric focusing patterns.

Lipids of dermatophytes

This investigation deals with phosphatides and fatty acid content of Epidermophyton floccosum, Microsporum cookie and Trichophyton mentagrophytes during different phases of growth. Total phosphatide content of these dermatophytes decreased with age, which was reflected in constituent major phosphatides. The zwitterionic and anionic phospholipids tended to maintain a constant ratio. Short chain fatty acids increased significantly with age in E. floccosum whereas these fatty acids represented a minor fraction of the total fatty acids in M. cookie and T. mentagrophytes. The ratio of saturated to unsaturated fatty acids increased 4-fold during growth in E. floccosum, whereas this increase was marginal in M. cookie. This ratio decreased in T. mentagrophytes.

Fatty acids of dermatophytes

The cellular fatty acids (C11-C20) from 18 species and strains within the genera Microsporum, Trichophyton, and Epidermophyton were determined by gas liquid chromatography. In addition, the effects of incubation time and temperature on fatty acid composition were investigated in selected species. The dermatophytes investigated represented anthropophilic, geophilic, and zoophilic species. Linoleic (18:2), oleic (18:1), and palmitic acid (16:0), accounted for 83.6-94.5% of the fatty acids of dermatophytes. Fatty acid composition and degree of unsaturation did not show any correlations with taxonomic status or ecological group. Incubation time influenced fatty acid composition slightly, but tendencies towards unsaturation and chain elongation were not observed. Elevated incubation temperature (37 degrees C) tended to increase the degree of total fatty acid unsaturation.

Allergic delayed skin reactions from lipid fractions of trichophytin

Crude trichophytin was fractionated to find out if its lipid fraction could cause inflammatory delayed allergic skin reactions in dermatophyte-sensitized guinea pigs. The following fractions were obtained: polysaccharide-peptide, total lipids, total lipids without free fatty acids and free fatty acids. The crude trichophytin and polysaccharide-peptide fraction gave rise to strong and equal allergic delayed skin reactions after 24 h. The total lipids gave statistically significant weaker, but clearly positive reactions, and of the same degree as the free fatty acid fraction. The total lipids without free fatty acids did not produce reactions in the sensitized animals, indicating that free fatty acids are responsible for the allergic skin reactions. In some cases the free fatty acids showed comparatively intense reactions. It can be concluded that free fatty acids are antigenic substances that are, sometimes, involved in the allergic delayed skin reactions in dermatophytosis.