Activity of moxifloxacin in combination with vancomycin or teicoplanin against Staphylococcus aureus isolated from device-associated infections unresponsive to glycopeptide therapy.
We tested the in vitro bactericidal activity of moxifloxacin, a new 8-methoxyquinolone, alone and in combination with vancomycin or teicoplanin at different multiples of minimum inhibitory concentration (MIC) against 8 methicillin-ciprofloxacin-resistant Staphylococcus aureus (M-C-RSA) and 1 methicillin-ciprofloxacin susceptible S. aureus (M-C-SSA) recently isolated from device-associated infections unresponsive to or relapsing after glycopeptide therapy, despite device removal. MICs of vancomycin ranged from 1 to 4 microg/ml, MICs of teicoplanin ranged from 2 to 8 microg/ml; MICs of moxifloxacin were always 2 microg/ml against M-C-RSA isolates and 0.125 microg/ml against the M-C-SSA isolate. The 9 strains resulted tolerant when tested for vancomycin, teicoplanin, and moxifloxacin used alone at 2 x MIC. In all cases the combination of moxifloxacin and teicoplanin or vancomycin appeared to be bactericidal already at MIC concentration for glycopeptides plus 0.5 x MIC concentration for moxifloxacin. If these results are confirmed in vivo in animal experiments, the combination of moxifloxacin with glycopeptides might be useful for treating device-associated infections, and in preventing the frightening phenomenon of increasing MICs for glycopeptides.
Tarasi
A
A
U.O.D. di Medicina Interna I per l'Urgenza, Azienda Ospedaliera San Giovanni-Addolorata-Calvary, Rome, Italy.
Cassone
M
M
Monaco
M
M
Tarasi
D
D
Pompeo
M E
ME
Venditti
M
M
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001372:Aza Compounds; D002404:Catheterization / Q000009:adverse effects*; D020878:Device Removal; D004347:Drug Interactions; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D024841:Fluoroquinolones; D006020:Glycopeptides / Q000627:therapeutic use*; D006801:Humans; D007558:Italy; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D011804:Quinolines; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000209:etiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D017334:Teicoplanin / Q000494:pharmacology*; D017211:Treatment Failure; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D006020:Glycopeptides; D011804:Quinolines; D017334:Teicoplanin; D014640:Vancomycin; D000077266:Moxifloxacin