Abstract

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) holds promise as a potential tool for clinical identification of filamentous fungi. However, due to the lack of an appropriate extraction protocol and the difficulty of database building, the identification power of each system differs. In this study, we selected 126 clinical mould isolates comprising 28 species identified using internal transcribed spacer (ITS) sequencing as the reference method to evaluate three MALDI-TOF MS systems. When using cultures and sample preparation as recommended by the respective vendors, of the 126 strains tested, VITEK MS identified 121 (96.0%) to species-level and 124 (98.4%) to genus-level; Biotyper identified 53 (42.1%) to species-level and 54 (42.9%) to genus-level; Autof identified 74 (58.7%) to species-level and 76 (60.3%) to genus-level. For the Autof system, the tube extraction method recommended by the vendor performed better (59%) than the on-plate lysis (51%). Our study demonstrates that MALDI-TOF MS systems can successfully identify most clinically relevant fungi, while performance is still highly dependent on the database and sample preparation protocol.

中文翻译：

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三种不同的MALDI-TOF MS系统的多中心评估，用于鉴定临床相关的丝状真菌。

摘要

基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）有望成为临床鉴定丝状真菌的潜在工具。但是，由于缺乏适当的提取协议和数据库建立的困难，每个系统的识别能力是不同的。在这项研究中，我们选择了126种临床霉菌菌株，其中包括使用内部转录间隔区（ITS）测序鉴定的28种物种，以此作为参考方法来评估三种MALDI-TOF MS系统。当使用各自供应商推荐的培养物和样品制备方法时，在测试的126个菌株中，VITEK MS鉴定出121种（96.0％）为物种水平，124种（98.4％）为属水平。Biotyper确定了物种级别的53（42.1％）和属级别的54（42.9％）；Autof确定了74（58.7％）个物种级别和76（60。3％）到属级。对于Autof系统，供应商推荐的试管萃取方法比板上裂解法（51％）效果更好（59％）。我们的研究表明，MALDI-TOF MS系统可以成功鉴定出大多数与临床相关的真菌，而性能仍然高度依赖于数据库和样品制备方案。