Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Bacterial Strains Routinely Isolated in a Clinical Microbiology Laboratory
Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Bacterial Strains Routinely Isolated in a Clinical Microbiology Laboratory
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DOI：
10.1128/jcm.01794-09
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发表时间：
2010-05-01
影响因子：
9.4
通讯作者：
Prod'hom, G.
中科院分区：
文献类型：
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作者：
Bizzini, A.;Durussel, C.;Prod'hom, G.
基质辅助激光解吸电离飞行时间质谱 (MALDI-TOF MS) 最近被引入诊断微生物学实验室，用于鉴定从临床样本中分离的细菌和酵母菌株。在本研究中，我们前瞻性地将 MALDI-TOF MS 与传统表型方法进行比较，以鉴定常规分离株。通过直接沉积在目标板上或在甲酸-乙腈提取步骤后（如果最初未获得有效结果），通过 MALDI-TOF MS 对菌落进行分析。在常规方法鉴定的1,371株分离株中，MALDI-TOF MS推定鉴定出1,278株（93.2%）为种水平，73株（5.3%）鉴定为属水平，但有20株（1.5%）未获得可靠鉴定。在通过 MALDI-TOF MS 鉴定到物种水平的 1,278 个分离株中，初步鉴定出 63 个 (4.9%) 不一致的结果。大多数不一致的结果 (42/63) 是由于与系统数据库相关的分类学差异造成的，14 个结果是由于对所获得的 MALDI-TOF MS 谱图的辨别力差造成的，7 个结果是由于初始常规识别中的错误造成的。需要执行提取步骤才能获得 1,278 个有效分离株中 25.6% 的有效 MALDI-TOF MS 鉴定。总之，我们的结果表明，MALDI-TOF MS 是一种快速可靠的技术，有可能取代临床微生物实验室常规分离的大多数细菌菌株的传统表型鉴定。
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been introduced in diagnostic microbiology laboratories for the identification of bacterial and yeast strains isolated from clinical samples. In the present study, we prospectively compared MALDI-TOF MS to the conventional phenotypic method for the identification of routine isolates. Colonies were analyzed by MALDI-TOF MS either by direct deposition on the target plate or after a formic acid-acetonitrile extraction step if no valid result was initially obtained. Among 1,371 isolates identified by conventional methods, 1,278 (93.2%) were putatively identified to the species level by MALDI-TOF MS and 73 (5.3%) were identified to the genus level, but no reliable identification was obtained for 20 (1.5%). Among the 1,278 isolates identified to the species level by MALDI-TOF MS, 63 (4.9%) discordant results were initially identified. Most discordant results (42/63) were due to systematic database-related taxonomical differences, 14 were explained by poor discrimination of the MALDI-TOF MS spectra obtained, and 7 were due to errors in the initial conventional identification. An extraction step was required to obtain a valid MALDI-TOF MS identification for 25.6% of the 1,278 valid isolates. In conclusion, our results show that MALDI-TOF MS is a fast and reliable technique which has the potential to replace conventional phenotypic identification for most bacterial strains routinely isolated in clinical microbiology laboratories.