dibekacin and cefuzonam

We determined the in vitro activities of arbekacin in combination with other antibiotics against 96 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Efficacies were evaluated by comparing frequencies of susceptible strains at concentrations of antibiotics present in serum 3 hours after intravenous administration of recommended dosages with those obtained with addition of 1 or 2 micrograms/ml of arbekacin. The addition of arbekacin significantly increased the antibacterial activities of cefotiam, cefuzonam, flomoxef and fosfomycin, but had no effect on the activity of either imipenem or minocycline. Arbekacin in combination with fosfomycin was found to have the greatest activity against MRSA among combinations tested. In addition, arbekacin had excellent antimicrobial activity against Pseudomonas aeruginosa, compared to other anti-pseudomonal agents such as piperacillin, ceftazidime and imipenem.

Topics: Aminoglycosides; Anti-Bacterial Agents; Cefotiam; Ceftizoxime; Cephalosporins; Dibekacin; Drug Therapy, Combination; Fosfomycin; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Staphylococcus aureus

Antibacterial effects of combination use of arbekacin (ABK) with cefotiam (CTM) or cefuzonam (CZON) were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and the following results were obtained. 1. Antibacterial effects of combinations of ABK with CTM and with CZON were equally potent against MRSA at clinically expected 1 MIC of ABK in blood. However, at a sub MIC of ABK the different effects were observed between the 2 combinations. The antibacterial effect of the former was strong and that of the latter was a little weak. 2. In either combination the potency of the antibacterial activity was less dependent on the concentration of CTM or CZON, but was strongly dependent on ABK concentrations. These results suggest that antibacterial effects of the combinations were highly dependent on antibacterial potency and concentration of ABK as previously reported for combinations of ABK with other drugs. 3. The combination use of ABK with CTM appears to be useful in cases of infection by MRSA alone while the combination use of ABK with CZON appears to be useful in cases of double infection with MRSA and Gram-negative bacterium.

Topics: Aminoglycosides; Anti-Bacterial Agents; Cefotiam; Ceftizoxime; Dibekacin; Dose-Response Relationship, Drug; Drug Resistance, Microbial; Drug Synergism; Methicillin Resistance; Staphylococcus aureus