Antimicrobial Activity of DC-159a, a New Fluoroquinolone, against 1,149 Recently Collected Clinical Isolates
AbstractAntimicrobial Activity of DC-159a, a New Fluoroquinolone, against 1,149 Recently Collected Clinical Isolates ▿ Ronald N. Jones 1 , 2 , * , Thomas R. Fritsche 1 and Helio S. Sader 1 , 3 1 JMI Laboratories, North Liberty, Iowa 2 Tufts University School of Medicine, Boston, Massachusetts 3 Universidade Federal de Sao Paulo, Sao Paulo, Brazil ABSTRACT The activity of DC-159a, a novel orally administered fluorinated quinolone, was evaluated by reference broth microdilution or agar dilution methods against 1,149 recently collected clinical isolates from five continents. Against pathogens associated with community-acquired respiratory tract infections (CA-RTIs), the MIC 90 s were 0.12 μg/ml for Streptococcus pneumoniae , 0.015 to 0.03 μg/ml for Haemophilus influenzae , 0.03 μg/ml for Moraxella catarrhalis , and 0.12 μg/ml for beta-hemolytic streptococci. Similarly, DC-159a was potent against various types of staphylococci (MIC 90 range, 0.03 to 2 μg/ml), Enterococcus faecalis (MIC 90 , 4 μg/ml), wild-type isolates of the family Enterobacteriaceae (MIC 90 range, 0.06 to 2 μg/ml), wild-type Pseudomonas aeruginosa (MIC 90 , 2 μg/ml), and Acinetobacter spp. (MIC 90 , 0.12 μg/ml). Fluoroquinolone-nonsusceptible organism subsets usually had elevated DC-159a MICs, but the MICs were often two- to fourfold lower than those of levofloxacin and moxifloxacin. In conclusion, DC-159a appears to possess a balanced broad spectrum of activity that exceeds the activities of the currently marketed fluoroquinolones, especially against pathogens that cause CA-RTIs.