飞行时间质谱系统微生物样本处理试剂与Bruker样本处理基质预处理对病原菌鉴定效能的影响研究

摘要

Objective To compare the impact of pre-processing on pathogen identification efficiency between Microorganism Sample Processing Reagent for Flight Time Mass Spectrometry System(Clin-TOF Reagent) and Bruker Sample Processing Matrix(Bruker Matrix).Methods A total of 103 routinely isolated bacterial strains were selected in the 302nd Hospital of the Chinese People's Liberation Army from January 2017 to May 2017,including 36 strains of Gram-negative bacteria,33 strains of Gram-positive bacteria and 34 strains of fungus. All of the bacterial strains were identified by Clin-TOF-Ⅱ type MS and Bruker Microflex MS after pre-processing of Clin-TOF Reagent and Bruker Matrix,respectively. Results On Clin-TOF-Ⅱ type MS,after pre-processing of Clin-TOF Reagent,baseline of mass spectrum was smooth, with relatively more specific signals,relatively high signal-to-noise ratio and better reproducibility,meanwhile it showed specific signals for Cryptococcus neoformans which were difficult to identify;after pre-processing of Bruker Matrix,the specific signals were less,the signal-to-noise ratio was lower,with poor reproducibility. On Clin-TOF-Ⅱ type MS,no statistically significant differences of single identification accuracy rate or 3-time parallel test identification accuracy rate of Gram-negative bacteria,or 3-time parallel test identification accuracy rate of fungus was found between pre-processing of Clin-TOF Reagent and pre-processing of Bruker Matrix(P>0.05),while single identification accuracy rate and 3-time parallel test identification accuracy rate of Gram-positive bacteria,and single identification accuracy rate of fungus after pre-processing of Clin-TOF Reagent were statistically significantly higher than those after pre-processing of Bruker Matrix(P<0.05). On Bruker Microflex MS,no statistically significant differences of single identification accuracy rate or 3-time parallel test identification accuracy rate of Gram-negative bacteria or Gram-positive bacteria,or single identification accuracy rate of fungus was found between pre-processing of Clin-TOF Reagent and pre-processing of Bruker Matrix(P>0.05),while 3-time parallel test identification accuracy rate of fungus after pre-processing of Clin-TOF Reagent was statistically significantly higher than that after pre-processing of Bruker Matrix(P<0.05).Conclusion Compared with Bruker Matrix,pre-processing of Clin-TOF Reagent has higher identification accuracy rate of Gram-positive bacteria and fungus on Clin-TOF-Ⅱ type MS,has higher identification accuracy rate of fungus on Bruker Microflex MS.%目的 比较飞行时间质谱系统微生物样本处理试剂(Clin-TOF试剂)与Bruker样本处理基质液(Bruker基质液)预处理对病原菌鉴定效能的影响.方法 选取2017年1—5月中国人民解放军第302医院临床常规分离的菌株103株,其中革兰阴性菌36株、革兰阳性菌33株、真菌34株.分别采用Clin-TOF试剂和Bruker基质液预处理后在Clin-TOF-Ⅱ型基质辅助激光解吸电离飞行时间质谱(MS)系统和布鲁克基质辅助激光解吸电离飞行时间质谱(Bruker Microflex MS)系统上进行菌种鉴定.结果 在Clin-TOF-Ⅱ型MS系统上,采用Clin-TOF试剂预处理供试菌株后所得质谱图基线平滑,特征信号较多,信噪比较高,重现性较好,且对较难鉴定的新型隐球菌也能检测出特征信号;采用Bruker基质液预处理供试菌株后所得质谱图特征信号较少,信噪比较低,重现性较差.在Clin-TOF-Ⅱ型MS系统上,Clin-TOF试剂预处理和Bruker基质液预处理后革兰阴性菌单次鉴定准确率、3次平行实验鉴定准确率及真菌3次平行实验鉴定准确率比较,差异无统计学意义(P>0.05);Clin-TOF试剂预处理后革兰阳性菌单次鉴定准确率、3次平行实验鉴定准确率及真菌单次鉴定准确率高于Bruker基质液预处理(P<0.05).在Bruker Microflex MS系统上,Clin-TOF试剂预处理和Bruker基质液预处理后革兰阴性菌单次鉴定准确率、3次平行实验鉴定准确率,革兰阳性菌单次鉴定准确率、3次平行实验鉴定准确率,真菌单次鉴定准确率比较,差异无统计学意义(P>0.05);Clin-TOF试剂预处理后真菌3次平行实验鉴定准确率高于Bruker基质液预处理(P<0.05).结论 与Bruker基质液相比,采用Clin-TOF试剂预处理供试菌株后Clin-TOF-Ⅱ型MS系统对革兰阳性菌及真菌的鉴定准确率较高,Bruker Microflex MS系统对真菌的鉴定准确率较高.