基于MALDI-TOF MS与FCM联合应用对临床血流感染病原体鉴定和药敏试验新方法的建立和应用

A New Method Aimed to Quickly Identify Pathogen and Drug Susceptibility Test Based on MALDI-TOF MS Combined with FCM

目的探讨基质辅助激光解吸电离飞行时间质谱技术(MALDI-TOF MS)与流式细胞学(FCM)联合应用在临床血流感染(BSI)病原体快速鉴定和药敏试验中的意义及应用价值。方法采用分离胶-吸附法菌体分离系统直接将菌体从血培养阳性瓶中分离,通过流式细胞学(FCM)与基质辅助激光解吸电离飞行时间质谱技术(MALDI-TOF MS)联合应用,快速对病原体进行鉴定和药敏试验。结果 MALDI-TOF MS法和VITEK2系统对常见菌都有超过90%的鉴定到种的能力(t=12.70,P=0.213)。MALDI-TOF MS较VITEK2有更高的鉴定到群和属的能力(t=6.31,P=0.027;t=8.64,P=0.031)。FCM法的药敏结果与VITEK2系统结果几乎完全一致(t=4.30,P=0.127),且FDA的加入可以很好地发现感染菌群中的耐药异质性。结论联合应用MALDI-TOF MS与FCM对临床BSI病原体进行鉴定和药敏试验的结果与传统方法间有很好的一致性,且报告时间可由传统的36,72h缩短至3h以内。该方法对BSI的快速诊断有较大意义和较好的临床应用价值。

Objective To discuss the significance and applied value in the rapid identification and drug susceptibility test for bloodstream infection（BSI）using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry（MALDI-TOF MS）combined with flow cytometry（FCM）.Methods The bacteria were separated from the positive blood culture bottle using separation gel-adsorption method system,and then applyed MALDI-TOF MS combined with FCM to identify pathogen and drug susceptibility test quickly.Results The efficiency of the separation gel-adsorption method for gram-negative bacterium,gram-positive bacteria and fungi were 71%,74% and 88% separately.The results of identifying pathogen using MALDI-TOF MS accord with results using VITEK2,both methods could identify 90% bacteria to species（t=12.70,P=0.213）.The MALDI-TOF MS had higher ability to identify groups and genera than VITEK2（t=6.31,P=0.027;t=8.64,P=0.031）.The results of drug susceptibility test using FCM was practically identical to VITEK2（t=4.30,P=0.127）,besides,the addition of FDA could find the heterogenic drug-resistant strains well.Conclusion They could quickly identify pathogen and drug susceptibility test based on MALDI-TOF MS combined with FCM,which was consistent with the traditional methods and could shorten the report time from 36,72 hto 3 h.More importantly,this methods are of great significance and clinical importance for the rapid identification of bloodstream infection.