The in-vitro activity of trovafloxacin, a new fluoroquinolone, against Gram-positive bacteria.

The in-vitro activity of trovafloxacin, a new quinolone, was compared with that of ciprofloxacin, erythromycin, various -lactam antibiotics and, where appropriate, clindamycin and vancomycin against a range of Gram-positive bacteria including staphylococci (n = 201), Streptococcus pneumoniae (n = 83), -haemolytic streptococci (n = 46), viridans group streptococci (n = 100), Streptococcus milleri (n = 18) and enterococci (n = 161) by an agar dilution technique. In addition, time‐kill studies were performed to estimate the bactericidal activity of trovafloxacin against S. milleri and viridans group streptococci. Trovaflo x a c i n was the most active agent tested against staphylococci. It also showed good activity, at least four-fold and usually eight- to 16-fold that of ciprofloxacin , against all the streptococci. Trovafloxacin showed good activity against vancomycin-sensitive Enterococcus faecalis and Enterococcus faecium, but was less active against the 11 isolates of vancomycin-re sistant enterococci. Trovafloxacin showed comparable or superior bactericidal activity to amoxy cillin against the S. milleri and viridans group streptococci tested.