title: Membrane-disorganizing property of polymyxin B nonapeptide.
abstract: The possibility of improving the antibacterial activities of drugs normally excluded by Gram-negative bacteria with polymyxin B nonapeptide (PMBN) has been explored. In vitro, PMBN rendered clindamycin, erythromycin, novobiocin, rifampicin and vancomycin very active against a number of Gram-negative enteric bacteria. The drug also sensitized the previously resistant bacterial strains to human, mouse or guinea pig serum. However, parenterally administered PMBN failed to influence bacterial growth in chambers implanted into mice and guinea pigs. It was also ineffective in experimental septicaemia at a dose of up to 200 mg/kg or when combined with antibiotics with which it interacted synergistically in vitro.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001770:Blood Bactericidal Activity / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D004357:Drug Synergism; D004755:Enterobacteriaceae / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D051379:Mice; D011112:Polymyxin B / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use; D011113:Polymyxins / Q000494:pharmacology*; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D018805:Sepsis / Q000188:drug therapy
chemical_list: D000900:Anti-Bacterial Agents; D011113:Polymyxins; C038934:polymyxin B nonapeptide; D011112:Polymyxin B