title: Comparative in vitro activity of levofloxacin and ofloxacin against gram-positive bacteria.
abstract: The in vitro activity of levofloxacin against 506 Gram-positive bacteria was compared with those of D(-)-ofloxacin, ofloxacin, ciprofloxacin, and sparfloxacin. Levofloxacin was generally twice as active as ofloxacin against these organisms (range, 0-3 twofold dilutions). Sparfloxacin appeared to have the greatest activity overall, but for several groups of organisms minimum inhibitory concentrations (MIC90s) of this compound were within one twofold dilution of those of levofloxacin. Resistance to levofloxacin (MIC > or = 8 micrograms/ml) was not encountered among streptococcal species, was rare in methicillin-susceptible staphylococci (1.7%), and was infrequent in vancomycin-susceptible Enterococcus faecalis and Enterococcus faecium (8.7%). Resistance was more common among vancomycin-resistant enterococci and methicillin-resistant staphylococci.
authors.affiliation: Department of Medicine, Deaconess Hospital, Boston, Massachusetts 02215, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Eliopoulos
authors.forename: C B
authors.initials: CB
authors.lastname: Wennersten
authors.forename: R C
authors.initials: RC
authors.lastname: Moellering
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects; D016984:Enterococcus faecium / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D064704:Levofloxacin; D008712:Methicillin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D015242:Ofloxacin / Q000494:pharmacology*; D010406:Penicillins / Q000494:pharmacology; D013210:Staphylococcus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D010406:Penicillins; D064704:Levofloxacin; D014640:Vancomycin; D015242:Ofloxacin; D008712:Methicillin