In vitro and in vivo potency of polymyxin B against IMP-type metallo-β-lactamase-producing Pseudomonas aeruginosa

摘要: Multidrug-resistant Pseudomonas aeruginosa, especially metallo-beta-lactamase (MBL)-producing P. is an important pathogen in nosocomial infection and emergence of this has revived interest polymyxin B (PMB) colistin (COL). In study, we evaluated the efficacies PMB, COL other antipseudomonal agents against IMP-type MBL-producing aeruginosa both vitro vivo. A total 75 isolates bla(IMP)-positive obtained from clinical specimens (94.6% demonstrated resistance to beta-lactam, fluoroquinolone aminoglycoside agents) were study. More than 90% examined susceptible PMB (minimum inhibitory concentration for 50/90% (MIC(50)/MIC(90)) 4/4 mg/L), although was less potent (MIC(50)/MIC(90) 8/16 mg/L). Cyclophosphamide-treated mice intraperitoneally inoculated with aeruginosa. Treatment but not COL, imipenem/cilastatin or aztreonam, significantly improved survival rate decreased number bacteria blood a dose-dependent manner. Our results indicate that, among studied, most effective agent