In Vitro Susceptibility of Anaerobes to Quinolones in the United States

• Published in: Clinical infectious diseases Vol. 23; no. Supplement-1; pp. S2 - S8
• Main Authors: Hecht, David W., Wexler, Hannah M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Chicago, IL The University of Chicago Press 01-12-1996; University of Chicago Press
• Subjects: Anaerobic bacteria; Anti-Infective Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacteria, Anaerobic - drug effects; Bacteria, Anaerobic - isolation & purification; Bacteroides; Bacteroides fragilis; Biological and medical sciences; Culture Media; Drug Resistance, Microbial; Evaluation Studies as Topic; Fluoroquinolones; Fusobacteria; Geometric mean; Humans; In Vitro Techniques; Inoculum; Levofloxacin; Medical sciences; Microbial Sensitivity Tests - methods; Naphthyridines - pharmacology; Ofloxacin - pharmacology; Peptostreptococcus; Pharmacology. Drug treatments; Piperazines - pharmacology; Prevotella; Quinolones; Quinolones - pharmacology; United States; United States; North America; America; Bacteria; Antibiotic; Fluoroquinolone derivatives; Drug susceptibility test; Anaerobe; In vitro
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1093/clinids/23.Supplement_1.S2

The in vitro activity of early fluoroquinolone antibiotics—including ciprofloxacin, ofloxacin, fleroxacin, pefloxacin, enoxacin, and lomefloxacin—against most anaerobes has been limited, a characteristic making them poor choices as antianaerobic agents. Newer fluoroquinolones, including levofloxacin, sparfloxacin, and grepafloxacin, have moderate activity against anaerobes, including the Bacteroides fragilis group as well as Clostridium, Peptostreptococcus, Prevotella, and Fusobacterium species. Fluoroquinolones that demonstrate the greatest activity against the B. fragilis group and other anaerobes include DU-6859a, clinafloxacin, and the related naphthyridone, trovafloxacin. There has been wide variation in the susceptibility results among different studies testing the same antibiotic; such variation may be due in part to the use of different methodologies, inoculum sizes, and testing media. In a direct comparison of susceptibility findings for ciprofloxacin, ofloxacin, and levofloxacin in three different media, we have determined that twofold dilution differences in minimum inhibitory concentration (MIC) values (MIC90, mode MIC, and geometric mean MIC) may occur in association with the choice of testing media. Thus, testing media should be considered when comparing results of different studies on the susceptibility of anaerobes to fluoroquinolones.