法尼醇对白念珠菌和粪肠球菌混合生物膜体外抑制作用的研究

Inhibitory effect of farnesol on mixed biofilms of Candida albicans and Enterococcus faecalis in vitro

目的探讨法尼醇对白念珠菌和粪肠球菌混合生物膜的抑制作用。方法采用微量平板法制备24 h和48 h白念珠菌和粪肠球菌混合生物膜,每组膜分别加入不同浓度法尼醇(100~800μmol/L)培养24 h, XTT减低法检测法尼醇对白念珠菌和粪肠球菌混合生物膜的抑制作用,倒置显微镜下观察混合生物膜形态,激光共聚焦显微镜下观察法尼醇对白念珠菌和粪肠球菌混合生物膜的抑菌效果。结果法尼醇对白念珠菌和粪肠球菌混合生物膜有抑制作用,随着法尼醇浓度的增加,抑制作用呈上升趋势。培养24 h,抑制混合生物膜50%活性的法尼醇最低药物浓度(sessile minimum inhibitory concentration 50%,SMIC50)为150μmol/L;培养48 h,抑制混合生物膜50%活性的法尼醇SMIC50为200μmol/L。结论法尼醇对白念珠菌和粪肠球菌混合生物膜生长具有明显抑制作用。法尼醇对白念珠菌和粪肠球菌的混合生物膜抑制强度与法尼醇浓度和生物膜时相相关,高浓度法尼醇的抑制效果高于低浓度法尼醇。

Objective To investigate the inhibitory effect of farnesol on mixed biofilms of Candida albicans and Enterococcus faecalis. Methods The mixed biofilms of Candida albicans and Enterococcus faecalis were formed on flat-bottom 96-well microtiter plates and two study groups(24 h and 48 h group) were noted, then respectively incubated in the RPMI 1640 with different concentrations of farnesol(100-800 μmol/L) for 24 hours. The XTT reduction assay was employed to evaluate the inhibitory effect of farnesol on the mixed biofilms. Biofilms morphology was observed by inverted microscope. The antibacterial effect of farnesol on the mixed biofilms of Candida albicans and Enterococcus faecalis was observed under confocal laser scanning microscope. Results Farnesol had inhibitory effect on mixed biofilms of Candida albicans and Enterococcus faecalis, and the inhibitory effect increased with the increase of farnesol concentration. The sessile minimum inhibitory concentration 50%(sessile minimum inhibitory concentration 50%,SMIC50) of farnesol was 150 μmol/L for 24 hours and 200 μmol/L for 48 hours. Conclusion Farnesol can inhibit the growth of mixed biofilms of Candida albicans and Enterococcus faecalis. The inhibitory potency of farnesol is related to its concentration and the phase of biofilms, and high concentration of farnesol is more effective than low concentration.