Effect of composition of cellular lipids of formation of nonspecific antibiotic resistance of alkanotrophic rhodocoocci

The antibiotic resistance and lipid composition of rhodococci grown in rich organic media with gaseous or liquid n-alkanes were studied. Hydrocarbon-grown rhodococci exhibited an increased resistance to a wide range of antibiotics (aminoglycosides, linkosamides, macrolides, beta-lactams, and aromatic compounds). The enhanced antibiotic resistance of rhodococci grown on n-alkanes correlated with an increased content of total cell lipids (up to 14-28%) and saturated straight-chain fatty acids (C16:0, C18:0, C21:0) and was accompanied by the appearance of cardiolipin and phosphatidylglycerol in cells. These lipid compounds were supposed to promote the formation of nonspecific antibiotic resistance in rhodococci by decreasing the permeability of their cell envelope to antibiotics.