Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands.
J Clin Microbiol. 2010 Mar;48(3):900-7. doi: 10.1128/JCM.02071-09. Epub 2010 Jan 6.
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid diagnostics at low costs and can be considered an alternative for conventional biochemical and molecular identification systems in a conventional microbiological laboratory. First, we evaluated MALDI-TOF MS using 327 clinical isolates previously cultured from patient materials and identified by conventional techniques (Vitek-II, API, and biochemical tests). Discrepancies were analyzed by molecular analysis of the 16S genes. Of 327 isolates, 95.1% were identified correctly to genus level, and 85.6% were identified to species level by MALDI-TOF MS. Second, we performed a prospective validation study, including 980 clinical isolates of bacteria and yeasts. Overall performance of MALDI-TOF MS was significantly better than conventional biochemical systems for correct species identification (92.2% and 83.1%, respectively) and produced fewer incorrect genus identifications (0.1% and 1.6%, respectively). Correct species identification by MALDI-TOF MS was observed in 97.7% of Enterobacteriaceae, 92% of nonfermentative Gram-negative bacteria, 94.3% of staphylococci, 84.8% of streptococci, 84% of a miscellaneous group (mainly Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella [HACEK]), and 85.2% of yeasts. MALDI-TOF MS had significantly better performance than conventional methods for species identification of staphylococci and genus identification of bacteria belonging to HACEK group. Misidentifications by MALDI-TOF MS were clearly associated with an absence of sufficient spectra from suitable reference strains in the MALDI-TOF MS database. We conclude that MALDI-TOF MS can be implemented easily for routine identification of bacteria (except for pneumococci and viridans streptococci) and yeasts in a medical microbiological laboratory.
基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）适用于低成本的高通量和快速诊断，可以被认为是传统微生物学实验室中常规生化和分子鉴定系统的替代品。首先，我们使用先前从患者材料中培养并通过常规技术（Vitek-II、API 和生化试验）鉴定的 327 株临床分离株评估了 MALDI-TOF MS。通过 16S 基因的分子分析分析了差异。在 327 株分离株中，95.1%正确鉴定到属水平，85.6%正确鉴定到种水平。其次，我们进行了一项前瞻性验证研究，包括 980 株细菌和酵母的临床分离株。MALDI-TOF MS 的总体性能明显优于常规生化系统，正确鉴定种属的比例分别为 92.2%和 83.1%，且产生的错误属鉴定较少（分别为 0.1%和 1.6%）。MALDI-TOF MS 正确鉴定种属的比例分别为肠杆菌科 97.7%、非发酵革兰氏阴性菌 92%、葡萄球菌 94.3%、链球菌 84.8%、杂项组（主要为嗜血杆菌、放线杆菌、心杆菌、艾肯菌和金氏菌[HACEK]）84%和酵母 85.2%。MALDI-TOF MS 在鉴定葡萄球菌种属和 HACEK 组细菌属方面的性能明显优于常规方法。MALDI-TOF MS 的错误鉴定显然与 MALDI-TOF MS 数据库中缺乏足够的合适参考菌株的光谱有关。我们得出结论，MALDI-TOF MS 可以很容易地用于医学微生物学实验室中细菌（除肺炎球菌和草绿色链球菌外）和酵母的常规鉴定。
