title: In vitro and in vivo antibacterial activities of DC-159a, a new fluoroquinolone.
abstract: DC-159a is a new 8-methoxy fluoroquinolone that possesses a broad spectrum of antibacterial activity, with extended activity against gram-positive pathogens, especially streptococci and staphylococci from patients with community-acquired infections. DC-159a showed activity against Streptococcus spp. (MIC(90), 0.12 microg/ml) and inhibited the growth of 90% of levofloxacin-intermediate and -resistant strains at 1 microg/ml. The MIC 90s of DC-159a against Staphylococcus spp. were 0.5 microg/ml or less. Against quinolone- and methicillin-resistant Staphylococcus aureus strains, however, the MIC 90 of DC-159a was 8 microg/ml. DC-159a was the most active against Enterococcus spp. (MIC 90, 4 to 8 microg/ml) and was more active than the marketed fluoroquinolones, such as levofloxacin, ciprofloxacin, and moxifloxacin. The MIC 90s of DC-159a against Haemophilus influenzae, Moraxella catarrhalis, and Klebsiella pneumoniae were 0.015, 0.06, and 0.25 microg/ml, respectively. The activity of DC-159a against Mycoplasma pneumoniae was eightfold more potent than that of levofloxacin. The MICs of DC-159a against Chlamydophila pneumoniae were comparable to those of moxifloxacin, and DC-159a was more potent than levofloxacin. The MIC 90s of DC-159a against Peptostreptococcus spp., Clostridium difficile, and Bacteroides fragilis were 0.5, 4, and 2 microg/ml, respectively; and among the quinolones tested it showed the highest level of activity against anaerobic organisms. DC-159a demonstrated rapid bactericidal activity against quinolone-resistant Streptococcus pneumoniae strains both in vitro and in vivo. In vitro, DC-159a showed faster killing than moxifloxacin and garenoxacin. The bactericidal activity of DC-159a in a murine muscle infection model was revealed to be superior to that of moxifloxacin. These activities carried over to the in vivo efficacy in the murine pneumonia model, in which treatment with DC-159a led to bactericidal activity superior to those of the other agents tested.
authors.affiliation: Biological Research Laboratories IV, Daiichi Sankyo Co., Ltd., 16-13, 1-Chome Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan. hoshino.kazuki.d6@daiichisankyo.co.jp
authors.forename: Kazuki
authors.initials: K
authors.lastname: Hoshino
authors.forename: Kazue
authors.initials: K
authors.lastname: Inoue
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Murakami
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kurosaka
authors.forename: Kenji
authors.initials: K
authors.lastname: Namba
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kashimoto
authors.forename: Saori
authors.initials: S
authors.lastname: Uoyama
authors.forename: Ryo
authors.initials: R
authors.lastname: Okumura
authors.forename: Saito
authors.initials: S
authors.lastname: Higuchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Otani
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D019540:Area Under Curve; D004195:Disease Models, Animal; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D011018:Pneumonia, Pneumococcal / Q000188:drug therapy* / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones