Comparative in vitro activity of gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin and trovafloxacin against 4151 Gram-negative and Gram-positive organisms.

Gatifloxacin, grepafloxacin, moxifloxacin and trovafloxacin are fluoroquinolones with enhanced Gram-positive activity while retaining broad-spectrum activity against Gram-negative pathogens. Levofloxacin and ciprofloxacin are older quinolones with broad activity against Gram-negative pathogens and borderline activity against some Gram-positive organisms. We compared the in vitro activity of these compounds against 4151 Gram-negative and -positive organisms. Gatifloxacin, grepafloxacin, moxifloxacin and trovafloxacin were highly active against penicillin sensitive and resistant Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and Streptococcus agalactiae. Ciprofloxacin and levofloxacin were active but less potent. All compounds were highly active (overall) against Gram-negative pathogens with ciprofloxacin being the most active agent against Pseudomonas aeruginosa. Our data indicate that the advanced fluoroquinolones will be important compounds for treating infections caused by Gram-positive and Gram-negative pathogens.