title: Synergism between penicillin G and the antimicrobial ether lipid, rac-1-dodecylglycerol, acting below its critical micelle concentration.
abstract: rac-1-Dodecylglycerol (DDG) and penicillin G (Pen G) act synergistically to dramatically lower the minimum inhibitory concentration (MIC) of each other in four Gram-positive bacteria studied. At one-half its MIC, DDG ether lowered the MIC of Pen G 10- to 80-fold. Under the same conditions, Pen G lowered the MIC of DDG 4- to 7.5-fold. The critical micelle concentration of DDG was determined to be 7.93 mg/ml (0.0305 mM), which is approximately two-fold greater than the minimum inhibitory concentration of DDG determined in the presence of a protein-free chemically defined medium. This finding suggests that DDG is not killing bacteria through its detergent action. Pen G also did not alter the critical micelle concentration of DDG, which indicates that the synergism between these two agents is not related to micelle formation.
authors.affiliation: Department of Biochemistry, Temple University School of Medicine, Philadelphia, PA 19140.
authors.forename: H S
authors.initials: HS
authors.lastname: Ved
authors.forename: E
authors.initials: E
authors.lastname: Gustow
authors.forename: R A
authors.initials: RA
authors.lastname: Pieringer
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004357:Drug Synergism; D005989:Glycerides / Q000494:pharmacology*; D007848:Laurates / Q000494:pharmacology*; D007850:Lauric Acids / Q000494:pharmacology*; D008823:Micelles; D008826:Microbial Sensitivity Tests; D050178:Monoglycerides; D010400:Penicillin G / Q000494:pharmacology*; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D005989:Glycerides; D007848:Laurates; D007850:Lauric Acids; D008823:Micelles; D050178:Monoglycerides; C020777:monolaurin; D010400:Penicillin G