title: Dual inhibitory activity of sitafloxacin (DU-6859a) against DNA gyrase and topoisomerase IV of Streptococcus pneumoniae.
abstract: The in-vitro inhibitory activities of sitafloxacin (DU-6859a) and other quinolones against Streptococcus pneumoniae DNA gyrase and topoisomerase IV were measured. IC50s of levofloxacin, ciprofloxacin, sparfloxacin and tosufloxacin against DNA gyrase were almost three to 12 times higher than those against topoisomerase IV. On the other hand, sitafloxacin showed dual inhibitory activity against both enzymes and its IC50s were the lowest among those of the quinolones tested. These results suggest that sitafloxacin is an effective agent against pneumococcal infections and that the incidence of drug-resistant mutants is low.
authors.affiliation: New Product Research Laboratories I, Daiichi Pharmaceutical Co., Ltd, Tokyo, Japan. onode90j@daiichipharm.co.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Onodera
authors.forename: Y
authors.initials: Y
authors.lastname: Uchida
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Sato
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D024841:Fluoroquinolones; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000201:enzymology; D059005:Topoisomerase II Inhibitors
chemical_list: D000890:Anti-Infective Agents; D004791:Enzyme Inhibitors; D024841:Fluoroquinolones; D059005:Topoisomerase II Inhibitors; C076246:sitafloxacin; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II