评估VITEK2-COMPACT GN13与纸片扩散法测定粘质沙雷菌对亚胺培南药敏结果的可靠性研究

目的评估法国生物梅里埃VITEK2-COMPACT GN13药敏系统(VITEK2法)和纸片扩散法(K-B法)检测粘质沙雷菌对亚胺培南药敏结果的可靠性。方法本研究选取了50株金华市中心医院2014年6月至11月临床标本中分离出的非重复的粘质沙雷菌,分别采用VITEK2法、K-B法和微量肉汤稀释法测定其对亚胺培南的体外敏感性,以微量肉汤稀释法作为参考方法,评估VITEK2法、纸片扩散法与参考方法的分类一致率(CA%)。结果K-B法与参考方法的一致率为94.0%(47/50),仅有6.0%的小错误(MIE),未出现大错误(ME)和极大错误(VME);而VITEK2法与参考方法的一致率仅为48.0%(24/50),其中VITEK2法测定为敏感的菌株与参考方法的一致率达95.6%,但VITEK2法测定为耐药或中介的菌株与参考方法的一致率仅为7.4%,小错误率(MIE%)和大错误率(ME%)分别为55.6%和37.0%,未出现极大错误(VME)。结论 K-B法检测粘质沙雷菌对亚胺培南的药敏结果是比较可靠的;VITEK2法检测粘质沙雷菌对亚胺培南敏感的结果也是可靠的,但对亚胺培南非敏感结果的错误率(ME+MIE)高达到92.6%,实验室日常工作中若发现此类结果应采用K-B法或微量肉汤稀释法重新复核。

Evaluation of the reliability of VITEK2-COMPACT GN13 methods vs disk diffusion for testing susceptibility of Serratia marcescens to Imipenem

Abstract: Objective To evaluate the reliability of VITEK2-COMPACT GN13 vs disk diffusion method for testing the susceptibility of Serratia marcescens to Imipenem. Methods A total of 50 Serratia marcescens strains clinically isolated from Jinhua Municipal Central Hospital during June and November 2014 were selected. The in vitro minimum inhibition concentration (MIC) values of Imipenem were determined by VITEK2-COMPACT GN13, disk diffusion and broth microdilution methods, respectively. Categorical agreement (CA) rates of VITEK2-COMPACT GN13 and disk diffusion methods were determined by using broth microdilution method as the reference. Results The CA values of VITEK2-COMPACT GN13 and disk diffusion methods to Imipenem were 48% (24/50) and 94% (47/50) respectively as compared with broth microdilution method. The CA value of the sensitive clinical isolates was 95.6% by using VITEK2-COMPACT GN13 method as compared with broth microdilution method, while that of non-sensitive clinical isolates was 7.4% by using VITEK2-COMPACT GN13 method. The minor error (MIE) and major error (ME) rate was 55.6% and 37.0% by using VITEK2-COMPACT GN13 method, respectively. Conclusion Both disk diffusion and VITEK2-COMPACT GN13 methods can be used for testing Imipenem susceptibility, but for non-sensitive clinical isolates, the testing results by using VITEK2-COMPACT GN13 method should be verified by using disk diffusion method.