title: Enhanced liposome-mediated activity of piperacillin against staphylococci.
abstract: This study showed that encapsulation of the beta-lactam antibiotic piperacillin (PIP) by liposomes prepared with phosphatidylcholine and cholesterol (1:1) protected the drug from hydrolysis by staphylococcal beta-lactamase. This was demonstrated by growth inhibition of Staphylococcus aureus in the presence of the liposomal preparation containing PIP at a 50% MIC. Growth inhibition was also seen when exogenous beta-lactamase was added. Furthermore, adsorption of PIP onto the surface of liposomes containing buffer conferred a significant degree of protection against enzymatic hydrolysis of the drug, thus enhancing its antistaphylococcal activity.
mesh_terms: D002784:Cholesterol / Q000494:pharmacology; D008081:Liposomes; D010713:Phosphatidylcholines / Q000494:pharmacology; D010878:Piperacillin / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors; D001618:beta-Lactamases / Q000494:pharmacology
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D002784:Cholesterol; D001618:beta-Lactamases; D010878:Piperacillin