In-vitro activity of moxifloxacin combined with other antibacterials against methicillin-resistant Staphylococcus aureus

Killing kinetic experiments were performed with moxifloxacin, a novel fluor oquinolone, vancomycin, clarithromycin, cotrimoxazole, gentamicin, rifampic in and with moxifloxacin in combination with each of the above drugs agains t six methicillin-resistant Staphylococcus aureus clinical isolates. Half o f the strains were ciprofloxacin-resistant. The early bactericidal effect o f moxifloxacin alone was substantially greater than that of the other teste d drugs. No antagonism was observed between moxifloxacin and each of the ot her drugs. For each combination the mean decrease in the number of organism s (after 6 hours) was comparable to that achieved with moxifloxacin alone, however, when moxifloxacin was tested with gentamicin, a slight increase in the bactericidal effect was observed.