The in-vitro activity of RP 59500 against gram-positive cocci.

RP 59500 was more potent than erythromycin, josamycin, amoxycillin and ciprofloxacin, and as potent as vancomycin, against staphylococci and enterococci. Against streptococci, the activity of RP 59500 was very similar to that of amoxycillin, but was superior to that of erythromycin, josamycin, vancomycin or ciprofloxacin. Compared with the other antimicrobial agents tested, RP 59500 was the most active against erythromycin-resistant Gram-positive cocci.