Activity of newer fluoroquinolones in vitro against gram-positive bacteria

Several newer fluoroquinolones, which have been recently introduced or are under investigation, display substantially greater potency against Gram-pos itive organisms than the older generation agents of this class. Nevertheles s, for problem organisms including methicillin-resistant strains of Staphyl ococcus aureus and many Enterococcus faecium, concentrations of newer antim icrobials required to inhibit 90% of organisms in the collections studied r emain above those that are projected to be achievable with clinical use. Ne vertheless, enhanced potency of several newer quinolones may result in a fa vourable pharmacodynamic profile leading to improved outcomes against Gram- positive infections and possibly to the delayed or diminished emergence of resistance to these agents.