The relationship between staphylococcal lipid composition and resistance to parabens was investigated. Chloroform-methanol extractable lipids were determined gravimetrically. Phospholipid and fatty acid fractions were studied using thin layer chromatography, gas liquid chromatography and mass spectrometry. Consistent quantitative differences were found among the total lipid, phospholipid and fatty acid compositions of sensitive and resistant strains. Most notable was the fact that, in paraben resistant strains, the percentage of total lipid and the phosphatidyl glycerol fraction of phospholipids were greater than in paraben sensitive strains. Furthermore, paraben resistant strains showed decreases in cyclopropane-ring containing fatty acids as compared with sensitive strains. Since significant differences in total lipid, phospholipid and fatty acid fractions were noted, it was suggested that the resistance of Staphylococcus aureus to parabens was related to membrane lipid composition
