左氧氟沙星对牙周炎需氧及厌氧菌抗菌活性研究

目的 比较喹诺酮药物左氧氟沙星、氧氟沙星和环丙沙星对牙周炎需氧和厌氧菌抗菌活性。方法 牙周炎患者龈沟液中需氧和厌氧菌的分离培养。最低抑菌浓度(MIC)测定用琼脂稀释多点接触法。最低杀菌浓度(MBC)用肉汤稀释法，并用杀菌曲线方法比较两种喹诺酮药物杀菌性能。结果 喹诺酮药物有广谱的抗菌作用。左氧氟沙星对大肠埃希菌、肺炎链球菌、金黄色葡萄球菌、肠球菌和厌氧菌的MIC50分别为0．25、0．5、0．5、1和0．125μg／ml,，抗菌活性强于氧氟沙星和环丙沙星。对肺炎克雷伯菌、肠杆菌属细菌、变形菌、嗜血菌和不动杆菌的MIC50分别为＜0．03、＜0．03、＜0．03、0．125和0．03μg／ml，，抗菌活性强于氧氟沙星，但与环丙沙星相同。左氧氟沙星对铜绿假单胞菌抗菌活性稍弱于环丙沙星，左氧氟沙星的MIC是氧氟沙星和环丙沙星的2倍。结论 左氧氟沙星是一个广谱抗生素，对口腔需氧和厌氧菌显示了良好的抑菌和杀菌的活性。

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.