The in-vitro activity and tentative breakpoint of gemifloxacin, a new fluoroquinolone.

Abstract

The in-vitro activity of gemifloxacin, a new fluoroquinolone, against a wide range (c. 700) of recent clinical isolates, was compared with that of three other fluoroquinolones and other relevant agents. Gemifloxacin inhibited 90% of the Enterobacteriaceae strains at 0.5 mg/L or less, exceptions being Serratia spp. (MIC(90) 1 mg/L) and strains possessing a putative mechanism of resistance to fluoroquinolones. Ninety per cent of Pseudomonas aeruginosa were inhibited by 4 mg/L. Gemifloxacin had good activity against respiratory pathogens, with 90% of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis being inhibited by 0.06 mg/L or less. Staphylococcus aureus (MSSA) were highly susceptible (MIC(90) 0.06 mg/L) but MRSA less susceptible (MIC(90) 8 mg/L) to gemifloxacin. Enterococcus spp. were markedly more susceptible to the study agent than to ciprofloxacin. Gemifloxacin showed good activity against Bacteroides fragilis (MIC(90) 0.5 mg/L) and anaerobic cocci. A tentative in-vitro breakpoint of 0.5 mg/L was studied using a 1 microg disc content for all genera except Pseudomonas where a 5 microg disc content was employed. The false sensitivity reporting rate was 0.5% and false resistance rate was 6.0%, which was considered acceptable. In conclusion, gemifloxacin is a highly active fluoroquinolone that should prove clinically useful in the treatment of a wide range of infections. Susceptibility testing criteria have been developed that should prove robust in a clinical laboratory.

• Authors: R Wise, J M Andrews
• Journal: The Journal of antimicrobial chemotherapy (J Antimicrob Chemother) Vol. 44 Issue 5 Pg. 679-88 (Nov 1999) ISSN: 0305-7453 [Print] England
• PMID: 10552986 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Anti-Infective Agents
• Fluoroquinolones
• Naphthyridines
• Gemifloxacin

Topics

• Anti-Bacterial Agents (pharmacology)
• Anti-Infective Agents (pharmacology)
• Bacteria (drug effects)
• Bacterial Infections (microbiology)
• Evaluation Studies as Topic
• Fluoroquinolones
• Gemifloxacin
• Humans
• Microbial Sensitivity Tests (methods, standards)
• Naphthyridines (pharmacology)