Validation of a New Web Application for Identification of Fungi by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
Validation of a New Web Application for Identification of Fungi by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
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DOI：
10.1128/jcm.00263-17
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发表时间：
2017-09-01
影响因子：
9.4
通讯作者：
Piarroux, R.
中科院分区：
文献类型：
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作者：
Normand, A. C.;Becker, P.;Piarroux, R.
基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱已成为一种可靠的技术，以确定涉及人类疾病的霉菌，包括皮肤癣菌，提供详尽的参考数据库。该研究评估了基于原始算法和包含11，851个光谱（938个真菌物种和246个真菌属）的广泛内部参考数据库的在线识别应用程序。使用422种霉菌（包括皮肤癣菌）的初始面板建立验证标准，这些霉菌先前通过DNA测序（126种）鉴定。使用来自五家医院实验室的501株培养的临床分离株（88种霉菌分类群，包括皮肤癣菌）的单独小组进一步评估了该应用。共438株（87.35%）菌株在种水平上被正确鉴定，而26株（5.22%）被分配到正确的属，但错误的种，37株（7.43%）未被鉴定，因为未达到定义的阈值20。使用MALDI Biotyper软件中包含的Bruker Daltonics数据库导致了更高的未鉴别分离株率（使用评分阈值1.7和2.0时分别为39.76%和74.30%）。此外，在线应用程序的识别延迟仍然与实时在线查询兼容（每个光谱0.15秒），并且该应用程序比使用MALDI Biotyper软件的识别更快。这是第一项基于MALDI-TOF光谱分析评估在线识别系统的研究。我们已经成功地应用这种方法来确定模具，包括皮肤真菌，其中的多样性是不够的商业数据库中表示。这个免费访问的应用程序可用于医学真菌学家，以提高真菌鉴定。
Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry has emerged as a reliable technique to identify molds involved in human diseases, including dermatophytes, provided that exhaustive reference databases are available. This study assessed an online identification application based on original algorithms and an extensive in-house reference database comprising 11,851 spectra (938 fungal species and 246 fungal genera). Validation criteria were established using an initial panel of 422 molds, including dermatophytes, previously identified via DNA sequencing (126 species). The application was further assessed using a separate panel of 501 cultured clinical isolates (88 mold taxa including dermatophytes) derived from five hospital laboratories. A total of 438 (87.35%) isolates were correctly identified at the species level, while 26 (5.22%) were assigned to the correct genus but the wrong species and 37 (7.43%) were not identified, since the defined threshold of 20 was not reached. The use of the Bruker Daltonics database included in the MALDI Biotyper software resulted in a much higher rate of unidentified isolates (39.76 and 74.30% using the score thresholds 1.7 and 2.0, respectively). Moreover, the identification delay of the online application remained compatible with real-time online queries (0.15 s per spectrum), and the application was faster than identifications using the MALDI Biotyper software. This is the first study to assess an online identification system based on MALDI-TOF spectrum analysis. We have successfully applied this approach to identify molds, including dermatophytes, for which diversity is insufficiently represented in commercial databases. This freeaccess application is available to medical mycologists to improve fungal identification.