title: In vitro antibacterial activities of DQ-113, a potent quinolone, against clinical isolates.
abstract: The antibacterial activity of DQ-113, formerly D61-1113, was compared with those of antibacterial agents currently available. MICs at which 90% of the isolates tested are inhibited (MIC90s) of DQ-113 against clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus and methicillin-susceptible and -resistant coagulase-negative staphylococci were 0.03, 0.008, 0.03, and 0.06 microg/ml, respectively. Moreover, DQ-113 showed the most potent activity against ofloxacin-resistant and methicillin-resistant S. aureus, with a MIC90 of 0.25microg/ml. DQ-113 inhibited the growth of all strains of Streptococcus pneumoniae, including penicillin-resistant strains, and Streptococcus pyogenes at 0.06 microg/ml, and DQ-113 was more active than the other quinolones tested against Enterococcus faecalis and Enterococcus faecium with MIC90s of 0.25 and 2 microg/ml, respectively. Against vancomycin-resistant enterococci, DQ-113 showed the highest activity among the reference compounds, with a MIC range from 0.25 to 2 microg/ml. DQ-113 also showed a potent activity against Haemophilus influenzae, including ampicillin-resistant strains (MIC90, 0.015 microg/ml), and Moraxella catarrhalis (MIC90, 0.03 microg/ml). The activity of DQ-113 was roughly comparable to that of levofloxacin against all species of ENTEROBACTERIACEAE: The MICs of DQ-113 against ofloxacin-susceptible Pseudomonas aeruginosa ranged from 0.25 to 2 microg/ml, which were four times higher than those of ciprofloxacin. From these results, DQ-113 showed the most potent activity against gram-positive pathogens among antibacterial agents tested.
authors.affiliation: New Product Research Laboratories I, Daiichi Pharmaceutical Co. Ltd., Tokyo, Japan. tanakpmj@daiichipharn.co.jp
authors.forename: Mayumi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Emi
authors.initials: E
authors.lastname: Yamazaki
authors.forename: Megumi
authors.initials: M
authors.lastname: Chiba
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Yoshihara
authors.forename: Takaaki
authors.initials: T
authors.lastname: Akasaka
authors.forename: Makoto
authors.initials: M
authors.lastname: Takemura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sato
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001424:Bacterial Infections / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D024841:Fluoroquinolones; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; C456082:DQ113; D024841:Fluoroquinolones; D015363:Quinolones