微量肉汤稀释法比较分析不同培养时间念珠菌属对唑类药物的敏感性

Comparison of azoles MICs against Candida spp.determined by the broth microdilution method at different incubation time

目的探讨微量肉汤稀释法检测念珠菌属对唑类药物的体外敏感性时,培养24h和48h读取MIC值的差异。方法微量肉汤稀释法检测653株念珠菌对氟康唑、伏立康唑和伊曲康唑的体外药物敏感性,分别于24h和48h读取MIC值,比较不同孵育时间所得MIC总一致率(EA)、敏感性判定一致率(CA)及敏感性判定错误率(Error)。结果绝大多数念珠菌培养24h能够生长充分并进行MIC值读取;孵育24h和48h读取MIC值总EA较好,分别为:氟康唑(91.9%),伏立康唑(92.0%),伊曲康唑(95.6%);CA分别为氟康唑(96.9%),伏立康唑(90.4%),伊曲康唑(88.2%),不同菌种类型CA有差异;未发现极严重错误(VME)的结果,错误多为一般错误(MiE),653株菌敏感性判定错误率ME/MiE分别为氟康唑(1.7%/2.9%)、伏立康唑(2.0%/10.6%)和伊曲康唑(1.5%/13.0%)。结论微量肉汤稀释法检测念珠菌属对唑类药物体外敏感性时,孵育24h与48h MIC值一致率较好,24h读取MIC值可缩短药敏报告时间,减少拖尾现象导致的判读错误。

Objective To investigate the agreement between the 24 h and 48 h azoles MICs against Candida species by broth microdilution method.Methods Antifungal susceptibility testing was carried out by broth microdilution method against 653 Candida isolates and MICs were obtained at 24 h and 48 h incubation for assessing of essential agreement （EA）, categor- ical agreement （CA） and categorical error （Error）.Results Most of Candida isolates tested could obtain sufficient growth after 24 h incubation.The overall EAs of 24 h and 48 h MICs were excellent with the three azoles for most of the species,flu- conazole （91.9 % ）, vorieonazole （ 92.0 % ） and itraconazole （ 95.6 ~ ） ; the overall CAs were wonderful with flueonazole （ 96. 9 % ）, vorieonazole （90.4%） and itraconazole （88.2 %）, depending on the species type tested.Very major errors （VMEs） were absent in our study,minor errors were reported most of the time.The ME/MiE for the total 653 Candida isolates were flu- eonazole （1.7%/2.9%） ,voriconazole （2.0%/10.6%） and itraeonazole （1.5%/13.0%）.Conclusion These data suggested that the performance 24 h MIC readings gave results similar to those of 48 h MICs and reading MICs at 24 h incubation would shorten the MIC determination of azoles and avoid errors due to trailing misinterpretation.