白念珠菌对三唑类药物体外抗真菌敏感性及拖尾现象的研究

In vitro study of antifungal activities and trailing growth of triazoles against Candida albicans

目的:评价66株白念珠菌对三唑类药物的体外敏感性和拖尾现象。方法:参照CLSI的M27-A3方法进行,检测分离自不同部位的66株白念珠菌对氟康唑、伊曲康唑和伏立康唑的体外敏感性和拖尾现象,应用肉眼观察和酶标仪读取MIC结果。结果:依据判读折点,对氟康唑敏感菌株63株,剂量依赖3株,MIC几何均值为0.59μg/mL,对伊曲康唑敏感39株,剂量依赖25株,耐药2株,MIC几何均值为0.156μg/mL,对伏立康唑敏感65株,剂量依赖1株,MIC几何均值为0.059μg/mL。3种药物表现不同程度的拖尾现象,分光光度法读取吸光值可清晰反映出MIC值、菌量变化及拖尾现象。结论:拖尾现象是三唑类药物体外抗真菌敏感性检测的常见现象,分光光度法可以客观、直接地观察体外MIC结果及拖尾现象。

Objective： To evaluate the in vitro antifungal susceptibility to triazoles and trailing growth of 66 Can- dida albicans strains by micro- dilution method. Method： According to CLSI M27 - A3 micro - dilution method, in vitro susceptibility and trailing growth of 66 Candida albicans from different body sites to fluconazole, itraconazole and voriconazole were measured and the minimal inhibitory concentration （MIC） results were read by visual method and spectrophotometer method at the same time. Results： According to the breakpoints, 63 strains were sensitive to fluconazole, 3 strains dependent on fluconazole, with a geomean of MIC was 0.59 μg/mL. To itraconazole 39 strains were sensitive, 25 dependent and 2 resistant, with a geomean of MIC 0. 156 μg/mL. To voriconazole 65 were strains sensitive, 1 dependent, with a geomean of MIC 0. 059 μg/mL. Three kinds of azoles showed different trailing growth. The MIC, quantity change of strains and trailing growth were clearly reflected by spectrophotometer method. Condusion： The trailing growth is a common phenomenon of Candida albicans in vitro susceptibility test by micro - dilution method. Spectrophotometer method is an objective and direct method to investigate the MIC and trailing growth phenomenon.