[An in vitro study on combination effect of isepamicin and beta-lactam antibiotics].
A study was done on the combined actions of an aminoglycoside, isepamicin (ISP), and 3 beta-lactam antibiotics (cefoperazone (CPZ), latamoxef (LMOX) and imipenem/cilastatin sodium (IPM/CS] against clinical isolates of Pseudomonas aeruginosa, Serratia marcescens and Klebsiella pneumoniae. Minimal inhibitory concentrations of individual antibiotics were compared first. ISP and IPM/CS had strong antibacterial activities against all 3 bacterial species while the antibacterial activities of CPZ against P. aeruginosa and S. marcescens, and that of LMOX against P. aeruginosa were much weaker than those of IPM/CS or ISP. Fractional inhibitory concentration indices determined by the checker-board dilution method were compared next. ISP, when used in combination with beta-lactam antibiotics (CPZ, LMOX, or IPM/CS), showed synergistic or additive effect on most strains of the all 3 species, the combination of ISP and CPZ being most effective. Although less effective, synergistic or additive effects were also observed with the combinations of 2 beta-lactam antibiotics (CPZ and IPM/CS, LMOX and IPM/CS). Time course experiments demonstrated that ISP combined with CPZ had bactericidal activities against all 3 bacterial species at concentrations at which the respective drug alone showed only bacteriostatic activity.
Kumagai
K
K
Department of Microbiology, School of Medicine, Kyoto University.
Otsuki
H
H
Nishibuchi
M
M
Takeda
Y
Y
D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002438:Cefoperazone / Q000008:administration & dosage / Q000494:pharmacology; D015377:Cilastatin / Q000008:administration & dosage / Q000494:pharmacology; D000077728:Cilastatin, Imipenem Drug Combination; D004338:Drug Combinations; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000008:administration & dosage / Q000494:pharmacology; D005839:Gentamicins / Q000008:administration & dosage / Q000494:pharmacology*; D015378:Imipenem / Q000008:administration & dosage / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D009070:Moxalactam / Q000008:administration & dosage / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D012706:Serratia marcescens / Q000187:drug effects / Q000254:growth & development
D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D005839:Gentamicins; D015377:Cilastatin; D015378:Imipenem; D002438:Cefoperazone; D000077728:Cilastatin, Imipenem Drug Combination; C016927:isepamicin; D009070:Moxalactam