IN-VITRO ACTIVITY OF THE COMBINATION OF TROVAFLOXACIN AND OTHER ANTIBIOTICS AGAINST ENTEROCOCCI

The activities of trovafloxacin and ciprofloxacin against 38 strains o f non-beta-lactamase-producing enterococci, resistant to ampicillin, 3 4 strains susceptible to ampicillin, and 3 vancomycin-resistant entero cocci were studied. Tovafloxacin was move active than ciprofloxacin ag ainst all the enterococci studied. The ampicillin-resistant strains we re more susceptible than the ampicillin-susceptible strains to both ag ents. The effect of combining trovafloxacin with gentamicin, ampicilli n-sulbactam, novobiocin, rifampin, teicoplanin, and vancomycin was det ermined for 17 strains by the checkerboard method. An additive effect by inhibition was seen with all antibiotics studied. The results by ki lling varied with the different agents studied. Gentamicin, ampicillin -sulbactam, and novobiocin produced an additive killing effect with tr ovafloxacin. Reduced killing was seen when rifampin, vancomycin, or te icoplanin were added to trovafloxacin. (C) 1997 Elsevier Science Inc.