In Vitro Activities of Gatifloxacin against Bacteria isolated from Respiratory Specimens of Patients of University Hospitals in Korea

ABSTRACT

BACKGROUND: Gatifloxacin, a new 8-methoxyquinolone, has a broad-spectrum activity with expanded potency against respiratory pathogens. In this study, we examined the in vitro activity of gatifloxacin and comparators against recently isolated bacteria from respiratory specimens of patients in Korean hospitals. METHODS: Forty-nine isolates were from respiratory specimens of patients with acute exacerbations of chronic lower respiratory infections in eight university hospitals and 108 isolates were from respiratory specimens from patients of Yonsei University Hospital. Minimum inhibitory concentrations (MICs) were determined by NCCLS agar dilution method. RESULTS: MIC90 of gatifloxacin for Streptococcus pneumoniae was 1 g/mL, which was 8-fold and 2-fold lower than those of ciprofloxacin and levofloxacin, respectively. All strains of Haemophilus in fluenzae and Moraxella (Branhamella) catarrhalis were inhibited by < or =0.06 g/mL and < or =0.25 g/mL of gatifloxacin, respectively, and were susceptible to all fluoroquinolones tested. MIC90 of gatifloxacin for Klebsiella pneumoniae was 0.06 g/mL, which was 2-fold lower than those of levofloxacin and moxifloxacin. CONCLUSION: Gatifloxacin is highly active against S. pneumoniae, H. influenzae and M. (B.) catarrhalis isolated from respiratory specimens of patients of university hospitals in Korea.