In vitro activity of trovafloxacin (CP 99,219), a new fluoroquinolone against hospital isolates

The susceptibility of 492 Enterobacteriaceae, 227 other gram-negative bacte ria, 448 grampositive bacteria and 108 anaerobic organisms was determined b y the agar dilution method against trovafloxacin and other antibiotics. Tro vafloxacin was highly active against most of the Enterobacteriaceae includi ng Enterobacter spp. and Citrobacter spp. [minimum inhibitory concentration (MIC)90 <1 mg/l], Acinetobacter spp. and Pseudomonas aeruginosa (MIC90 = 0 .25 and 2 mg/l, respectively). The antimicrobial activity was extended to t he gram-positive bacteria including streptococci, Streptococcus pneumoniae, coagulase-negative staphylococci and methicillin-sensitive Staphylococcus aureus with MIC90 <1 mg/l. Enterococci and methicillin-resistant S. aureus were inhibited (MIC90 = 2 mg/l; sparfloxacin and ciprofloxacin were 16 and 64 mg/l, respectively). Almost all anaerobic organisms were inhibited by tr ovafloxacin (MIC90 = 1 mg/l).