微量稀释法测定抗真菌剂对酵母菌MIC的评价

Evaluation of the broth microdilution mehod for the determinations of the MIC s of antifungal agents against yeasts

目的 评价微量稀释法测定抗真菌剂对酵母菌最低抑菌浓度 (MICs)的可靠性和实用性。方法 应用微量稀释法和参考常量稀释法测定 5种抗真菌剂对 10 6株临床分离的酵母菌及 2株ATCC质控菌的MICs。结果 微量稀释法测得对念珠菌MICs 结果 (4 8h)与参考方法 (4 8h)比较 ,在± 1稀释度范围内总符合率为 93 2 % ,2株新型隐球菌 72h测定结果与参考方法相同。对 2株ATCC质控菌各测定 5 0次 ,则测定结果在质控中位数± 1稀释范围度内总符合率为 95 8%。结论 微量稀释法测定抗真菌剂对酵母菌MICs,其方法简便、结果准确可靠、重复性好 ,适合于常规工作。

Objective To evaluation the reliability and practicality of the broth microdilution method for the determinations of the minimal inhibitory concentrations(MIC s)of antifungal agents against yeasts.Methods The MIC s of the five antifungal agents against 106 yeasts isolated from clinical samples and 2 quality control strains were obtained from American Type Culture Collection were determined by the broth microdilution and the reference macrodilution methods.Resultsts The overall agreement within ±1 dilution of the reference macrodilution for the five antifungal agents against Candida spp.was 93 2%,when the MIC s were determined at 48 h by the broth microdilution method.Excellent agreement can also be observed for the five antifungal agents against 2 Cryptococcus neoformans isolates at the 72 h readings.General agreement of the MIC s within ±1 dilution for the five drugs tested against 2 quality control strains determined by the broth microdilution method was 95 8%.Conclusion These preliminary data indicate that the broth microdilution technique is a convenient,accurate and reliable method and suitable for the routine use in clinical laboratory.