熊果酸对金黄色葡萄球菌生物膜形成的影响

目的 研究熊果酸对金黄色葡萄球菌(S.aureus)生物膜形成的影响.方法 二倍稀释法测定熊果酸与左氧氟沙星对S.aureus的最低抑菌浓度(MIC),采用紫外法测定金黄色葡萄球菌的生长曲线,结晶紫染色法测定生物膜生成量,倒置显微镜下观察生物膜结构.结果 熊果酸对S.aureus的MIC为0.27 mmol/L,左氧氟沙星的为0.000 6 mmol/L,不同浓度熊果酸不仅对S.aureus浮游菌的生长有抑制作用,且能显著抑制其生物膜的形成,并呈浓度依赖性;与左氧氟沙星和熊果酸单独应用相比,熊果酸和左氧氟沙星联合用药更能显著抑制S.aureus生物膜形成,且差异具有统计学意义(P<0.01).结论 熊果酸与左氧氟沙星联用对抑制S.aureus生物膜形成有增效作用.

The inhibition effects of ursolic acid on biofilm formation of Staphylococcus aureus

Objective To study the effect of ursolic acid on the biofilm formation of Staphylococcus aureus. Methods Double dilution method was used to determine the minimum inhibitory concentration(MIC)of ursolic acid and levofloxacin. The growth curves of S. aureus of the normal group and ursolic acid group were detected by using a spectrophotometer,S. aureus biofilm was examined by crystal violet assay,and the biofilm structure was observed under optical microscope. Results The minimum inhibitory concentration(MIC)of ursolic acid and levofloxacin for S. aureus was 0.27 mmol/L and 0.000 6 mmol/L. Ursolic acid had good inhibitory activity for the early stages of biofilm formation in a dose-dependent manner,when combined with levofloxacin,ursolic acid resulted in a significant decrease in the established biofilm biomass compared to levofloxacin or ursolic acid used alone(P＜0.01). Conclusion Ursolic acid and levofloxacin have synergistic inhibitory effect on S. aureus biofilm formation.