ITS序列分析与MALDI-TOF MS质谱技术在丝状真菌鉴定中的应用

ITS sequence analyses and MALDI-TOF MS in the identification of filamentous fungi

丝状真菌常用的鉴定方法为形态方法和基因鉴定方法,前者限于检验人员的知识和技能,后者操作繁琐,费用略昂贵,不适合常规开展。因此,寻找丝状真菌快速鉴定方法势在必行。本文采用VITEK MALDI-TOF MS(基质辅助激光解析电离时间飞行质谱)IVD数据库(3.0版本)对临床分离的254株丝状真菌进行鉴定,并以ITS(internal transcribed spacer内转录间隔区)序列分析为标准,验证MALDI-TOF MS质谱技术鉴定丝状真菌的准确性。结果表明MALDI-TOFMS质谱技术可以对大部分丝状真菌实现快速、准确的鉴定,其中对毛癣菌属(100%)、毛孢子菌属(100%)、毛霉菌属(100%)、曲霉菌属(96.5%)准确率很高,对犬小孢子菌(75%)、镰刀菌属(50%)、新月弯孢霉(46.2%)准确率较低,对丝状真菌鉴定的总体准确率为86.36%,与ITS测序分析符合率为83.97%。

It is conventional to identify filamentous fungi using morphological methods and genetic identification method.However,the former methods are usually influenced by the knowledge and skills of the inspectors,while the latter is cumbersome and expensive,and both of them are not suitable for routine clinical development.Therefore,it is imperative to find a rapid identification method.In this study,254 clinical isolates of filamentous fungi were identified by MALDI-TOF MS(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry)IVD(3.0 version)and the accuracy of the results was verified by ITS(internal transcribed spacer).The results showed that MALDI-TOF MS can identify most filamentous fungi quickly and accurately.The accuracy for identification of Trichophyton(100%),Trichosporon(100%),Mucor(100%)and Aspergillus(96.5%)was remarkably high,that of Microsporum canis(75%),Fusarium(50%),Curvularia lunata(46.2%)unsatisfactory.The overall accuracy rate for identification of filamentous fungi was 86.36%,and the coincidence rate with the results of ITS sequencing analysis was 83.97%.