title: In-vitro activity of WIN 57273 compared to the activity of other fluoroquinolones and two beta-lactam antibiotics.
abstract: WIN 57273, a new fluoroquinolone, was four to 128-fold more active than ciprofloxacin and ofloxacin against Gram-positive bacteria. The MIC90 for Staphylococcus aureus was 0.015 mg/l and for S. epidermidis, 0.03 mg/l. All Lancefield group A, B, C, & G streptococci, Streptococcus bovis and S. pneumoniae were inhibited by less than or equal to 0.06 mg/l compared to 0.5 mg/l for tosufloxacin and 2 mg/l for ciprofloxacin. For anaerobic bacteria WIN 57273 had an MIC90 for bacteroides of 1 mg/l, and for Clostridium spp. 0.015.mg/l. WIN 57273 was less active than ciprofloxacin against Enterobacteriaceae, with an MIC90 of 1 mg/l, including aminoglycoside and cephalosporin-resistant isolates. The MIC90 of WIN 57273 for Pseudomonas aeruginosa was 2 mg/l, compared to 0.5 mg/l for ciprofloxacin. Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, and Legionella spp. were inhibited by 0.06 mg/l. WIN 57273 was more active against Gram-negative bacteria at acid pH, but activity was decreased by magnesium ions and an increase in inoculum. Resistant strains were selected after passage on antibiotic-containing agar.
authors.affiliation: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
authors.forename: N X
authors.initials: NX
authors.lastname: Chin
authors.forename: H C
authors.initials: HC
authors.lastname: Neu
mesh_terms: D000890:Anti-Infective Agents; D001421:Bacteria, Anaerobic / Q000187:drug effects*; D002939:Ciprofloxacin / Q000494:pharmacology*; D024841:Fluoroquinolones; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009287:Naphthyridines / Q000494:pharmacology; D015242:Ofloxacin / Q000494:pharmacology*; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D009287:Naphthyridines; D015363:Quinolones; C062556:Win 57273; D002939:Ciprofloxacin; D015242:Ofloxacin; C055185:tosufloxacin