Anti-gonococcal activity of gemifloxacin against fluoroquinolone-resistant strains and a comparison of agar dilution and Etest methods.
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 (MIC(90) 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 (MIC(90) 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 log(2) dilution step (essential agreement). The excellent potency of gemifloxacin indicates its potential for the treatment of infections with quinolone-resistant N. gonorrhoeae.
Jones
R N
RN
University of Iowa College of Medicine, Iowa City, IA 5224, USA. ronald-jones@uiowa.edu
Deshpande
L M
LM
Erwin
M E
ME
Barrett
M S
MS
Beach
M L
ML
D000890:Anti-Infective Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D024841:Fluoroquinolones; D000077735:Gemifloxacin; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009287:Naphthyridines / Q000494:pharmacology*; D009344:Neisseria gonorrhoeae / Q000187:drug effects*
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D009287:Naphthyridines; D000077735:Gemifloxacin