基质辅助激光解析电离飞行时间质谱用于产碳青霉烯酶肺炎克雷伯菌ST11分型的研究

A studyof typing ST11 of klebsiella pneumoniae producing carbapenemases by matrix-assisted laser desorption ionization-time of flight mass spectrometry

目的探讨基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)用于产碳青霉烯酶肺炎克雷伯菌ST11分型。方法收集2012年10月-2014年10月5所医院的80株产碳青霉烯酶肺炎克雷伯菌菌株。经多位点序列分析(MLST),28株为ST11型,52株为其他分型(other sequence type,OST)。通过MSP dendrogram聚类分析、MALDI Biotyper建立数据库、Clin Pro Tools建立模型3种方法研究ST11分型的可能性。结果 MSP dendrogram聚类分析在距离水平线1000处可将80株菌聚类分析为两类,敏感性为65.78%,特异性为92.85%。MALDI Biotyper数据库验证结果:18株ST11有1株菌分为OST,32株OST有2株菌被分为ST11,敏感性为89.47%,特异性为96.77%。Clin Pro Tools用其余菌株验证模型全部正确,敏感性和特异性均为100%。结论 MALDI-TOF MS可通过3种方法区别ST11与OST,以Clin Pro Tools软件建立模型的方法最可靠。

Objective To study the probability of typing ST11 of klebsiella pneumoniae producing carbapenemases by matrix？assisted laser desorption ionization？time of flight mass spectrometry. Methods From October 2012 to October 2014, we collected 80 i？solates of klebsiella pneumoniaes producing carbapenemases. We researched all isolates by MLST finding that 28 isolates were ST11 and 52 isolates were other sequence types. Through MSP dendrogram, creating databases by MALDI Biotyper and building models by Clin？Pro Tools to analysis the probability of typing ST11. Results At the distance level cutoff of 1000, 80 isolates were divided into two clusters. The susceptibility with MSP dendrogram was 65.78%, and the specificity was 92.85%. The results of testing databases were that 1 of 18 ST11 and 2 of 20 OST were false. The susceptibility and the specificity with MALDI Biotyper were respectively 89.47% and 96.77%. The results of checking model with remaining isolates by the ClinPro Tools were all correctly. The susceptibility and specificity were both 100%. Conclusion Through three methods,MALDI？TOF MS has detection performance for the ST11 and OST, but ClinPro Tools is the best.