酵母菌药敏试验常量与微量液体稀释法的比较

Comparison of macron and microdilution antifungal tests of yeast

目的 采用常量和微量稀释法检测酵母样菌对四种抗真菌药物的最低抑菌浓度（MIC），并将两种方法的MIC结果进行统计分析。方法 参照美国临床实验室标准化委员会（NCCLS）推荐的"酵母菌液体稀释法抗真菌药敏试验参考方法"，测定临床分离的20株酵母样菌。结果 两性霉素－B的两种方法对所有菌标的MIC值大多数落在两个稀释度范围内，但两种方法比较，多数MIC值≥两个稀释度。氟胞嘧啶对白色念珠菌、新型隐球菌和光滑球拟酵母菌两种方法中的MIC有90％得到相同的结果。两性霉素－B对所有菌株、酮康唑对新型隐球菌两种方法有显著性差异（P＜0．05）。微量法中新型隐 球菌在48h可以判定结果而常量法要72h才能判定结果。结论 通过两种方法的比较及统计分析表明，微量法与常量法有较好的相关性。微量法操作简便，节省试剂和药物，适合临床实验室应用。

 Objective To compare and analyse the minimum inhibitory concentration MIC of four antifungal drugs susceptible to yeasts． Methods Twenty clinical isolates of yeasts were examined according to the method introduced by the National Committee on Clinical Laboratory Standards NCCLS for broth dilution antifungal susceptibility testing of yeast． Results MIC endpoints were within two dilutions for all yeasts but comparison of MIC endpoints mostly were ≥ two dilutions with two methods to amphotericin－B． Similar results of 90％ were obtained in two methods with flucytosin against several isolates of C． albicans C． neoformans and T．glabrata． It was statistically significant P＜0．05 that two tests were observed with amphotericin－B against all the isolates and ketoconazole against C． neoformansC．Neoformans isolates in MIC were read at 48h in microdilution but 72h in macrodiution． Conclusion This study demonstrates a good correlation between broth microdilution and macrodilution． Microdilution technique is used proper clinical laboratory because it was more efficient easier to perform and economical asit requires smaller amount of reagents and antifungal drugs． so it is suitable for application in clinical laboratory． 