Antibacterial Activity of Levofloxacin against Isolates of Aerobe and Anaerobe in Periodontitis

OBJECTIVE To compare the in vitro activity of three quinolones against isolates of aerobe and anaerobe in periodontitis. METHODS Specimens were taken from the gingival crevicular fluid of periodontitis. The aerobic and anaerobic bacteria were cultured and identified. Minimal inhibitory concentration (MIC) was determined by agar dilution method using multipoint inoculator. The bactericidal activity of levofloxacin was tested using minimal bactericidal concentration (MBC) and killing curve methods. RESULTS Three quinolones had broad antibacterial spectrum. The activity of levofloxacin against Escherichia coli, Streptococcos pneumoniae, Staphylococcus aureus, Enterococcus species and anaerobe was stronger than that of ofloxacin and ciprofloxacin. The antibacterial activity of levofloxacin against Klebsiella pneumoniae, enteric pathogens, Proteus species, Haemophilus species and Acinetobacter species was stronger than that of ofloxacin but was similar to that of ciprofloxacin. The activity of levofloxacin against P. aeruginosa was weaker than that of ciprofloxacin. CONCLUSIONS Levofloxacin appears to have fine inhibitory and bactericidal activity against isolates of aerobe and anaerobe in periodontitis.