Journal of Antimicrobial Chemotherapy (2000) 45, 67
© 2000 The British Society for Antimicrobial Chemotherapy
Anti-gonococcal activity of gemifloxacin against fluoroquinolone-resistant strains and a comparison of agar dilution and Etest methods
University of Iowa College of Medicine, Iowa City, IA 5224, USA
Gemifloxacin is a novel quinolone with excellent activity against Gram-positive and some Gram-negative pathogens. Its activity was tested against 150 Neisseria gonorrhoeae strains, including 50 ciprofloxacin-resistant isolates, using reference agar dilution and Etest methods. Gemifloxacin was found to be highly potent against ciprofloxacin-susceptible strains (MIC90 0.008 mg/L), but was 16-fold less potent against ciprofloxacin-resistant gonococci. The order of quinolone potency against these fluoroquinolone-resistant mutants was: gemifloxacin (MIC90 0.12 mg/L) > trovafloxacin (0.25 mg/L) > moxifloxacin = grepafloxacin (0.5 mg/L) > ciprofloxacin (1 mg/L). Etest and reference agar dilution MIC results showed excellent correlation (r = 0.96) and >98% of MICs were within ±1 log2 dilution step (essential agreement). The excellent potency of gemifloxacin indicates its potential for the treatment of infections with quinolone-resistant N. gonorrhoeae.
* Correspondence address. Medical Microbiology Division, C606 GH, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA. Tel: +1-319-356-2990; Fax: +1-319-356-4916; E-mail: ronald-jones{at}uiowa.edu