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目的观察绿原酸联合左氧氟沙星对肺炎克雷伯菌生物膜的体外抑制现象。方法收集广州市中医医院临床分离的肺炎克雷伯菌株(排除同一患者同一部位重复菌株),应用半定量结晶紫法进行生物膜形成能力测定;选取3株生物膜强阳性的菌株,采用微量肉汤稀释法,对绿原酸、左氧氟沙星用MH肉汤倍比稀释,测定两者的最低抑菌浓度;棋盘稀释法测定绿原酸与左氧氟沙星的协同抑菌浓度;建立体外生物膜模型,经药物干扰,观察药物对生物膜形态的影响。结果在62株菌中共有33株为生物膜阳性,占53.2%,绿原酸对实验菌株的MIC分别是2 048、2 048和2 048μg/mL,左氧氟沙星的MIC分别是32、64和32μg/mL,两药联合作用,部分抑菌浓度指数(FIC)是0.5、0.5和0.5,提示两药呈协同作用,经体外建模及药物干扰,镜下药物组的黑色絮状物较未处理组明显减少。结论绿原酸具有抑制肺炎克雷伯菌生物膜作用,与左氧氟沙星联合,作用效果更显著。
Objective To observe the inhibitory effect of chlorogenic acid combined with levofloxacin against Klebsiella pneumoniae biofilm in vitro. Methods The clinical isolates of Klebsiella pneumoniae from Guangzhou TCM Hospital were collected, excluding the same patient with the same part of the same strain. The semi-quantitative crystal violet method was used to determine the biofilm formation ability. Three strains with strong biofilm were selected, The concentration of chlorogenic acid and levofloxacin was determined by the chessboard dilution method. The in vitro biofilm model was established by the drug dilution method Interference, observe the impact of drugs on the biofilm morphology. Results A total of 33 strains out of 62 were biofilm positive, accounting for 53.2%. The MICs of chlorogenic acid to the test strains were 2048, 2048 and 2048 μg / mL, respectively. The levofloxacin MICs were 32, 64 and 32 μg / mL, the combination of the two drugs, partial antibacterial concentration index (FIC) 0.5, 0.5 and 0.5, suggesting that the two drugs have a synergistic effect, by modeling in vitro and drug interference, microscopic flocculent drugs group than the untreated group obviously decrease. Conclusion Chlorogenic acid can inhibit the biofilm of Klebsiella pneumoniae, and its combination with levofloxacin is more effective.