Activity of moxifloxacin and other quinolones against pneumococci resistant to first-line agents, or with high-level ciprofloxacin resistance.
The activity of moxifloxacin and other quinolones was assessed against 288 epidemiologically diverse isolates of Streptococcus pneumoniae, many of them resistant to one or more first-line agents and/or with increased ciprofloxacin resistance (minimum inhibitory concentrations, MICs 16- > 64 mg/l compared with 1-2 mg/l for most isolates). Moxifloxacin and grepafloxacin were the most active quinolone analogues, inhibiting about 90% of the isolates at < or = 1 mg/l, whereas levofloxacin inhibited 64% of isolates at < = 1 mg/l and ciprofloxacin inhibited 42%. Moxifloxacin also was the most active agent against isolates with elevated ciprofloxacin resistance (MIC 16- > 64 mg/l): moxifloxacin MICs of around 4 mg/l were seen for most such isolates, compared with 16-32 mg for levofloxacin and grepafloxacin. The activity of moxifloxacin against pneumococci resistant to one or more first-line agent suggests it will have a useful therapeutic role, although its activity against highly ciprofloxacin resistant isolates seems marginal.
Johnson
A P
AP
Antibiotic Resistance Monitoring and Reference Laboratory, Central Public Health Laboratory, Colindale, NW9 5HT, London, UK. ajohnson@phls.nhs.uk
Warner
M
M
Livermore
D M
DM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001372:Aza Compounds; D002939:Ciprofloxacin / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D024841:Fluoroquinolones; D006801:Humans; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D015242:Ofloxacin / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011804:Quinolines; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D010879:Piperazines; D011804:Quinolines; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; C075375:grepafloxacin; D000077266:Moxifloxacin