In vitro activity of gemifloxacin against Streptococcus pneumoniae isolates in Germany

The MICs (minimal inhibitory concentrations) of gemifloxacin, moxifloxacin, ofloxacin, ciprofloxacin, levofloxacin, sparfloxacin, penicillin G, tetrac ycline and erythromycin were determined for 200 clinical pneumococcal isola tes using the microbroth dilution method. MIC50 and MIC90 values were as fo llows (mg/l): 0.016 and 0.016 (gemifloxacin, penicillin-intermediate strain s), 0.03 and 0.06 (gemifloxacin, penicillin-susceptible strains); 0.125-0.5 and 0.25 (moxifloxcacin); 1-2 and 4 (ciprofloxacin and ofloxacin); 1 and 2 (levofloxacin), and 0.25-0.5 and 0.5 (sparfloxacin). MIC50 and MIC90 value s for the fluoroquinolones were nearly identical for individual antimicrobi al agents in the penicillin-susceptible and penicillin-intermediate groups of strains. Erythromycin and tetracycline were less active against penicill in-intermediate pneumococci isolates (erythromycin: MIC90 8 mg/l; MIC range 0.06-greater than or equal to 64 mg/l; tetracycline: MIC90 greater than or equal to 64 mg/l, MIC range 0.25- greater than or equal to 64 mg/l) as com pared to penicillin-susceptible isolates (erythromycin: MIC90 0.5 mg/l, MIC range 0.06-greater than or equal to 64 mg/l; tetracycline: MIC90 8 mg/l, M IC range 0.06-greater than or equal to 64 mg/l). Copyright (C) 2001 S. Karg er AG, Basel.