Direct Bacterial Identification in Positive Blood Cultures by Use of Two Commercial Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Systems
Direct Bacterial Identification in Positive Blood Cultures by Use of Two Commercial Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Systems
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DOI：
10.1128/jcm.03259-12
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发表时间：
2013-06-01
影响因子：
9.4
通讯作者：
Yam, Wing-Cheong
中科院分区：
文献类型：
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作者：
Chen, Jonathan H. K.;Ho, Pak-Leung;Yam, Wing-Cheong
基质辅助激光解吸电离飞行时间质谱仪(MALDI-TOF MS)用于细菌和真菌的鉴定是最近在微生物学实验室引入的。这项技术可以极大地改善患者的临床管理和指导化疗。在这项研究中，我们使用一种商用MALDI Sepsityper提取方法来评估两种商用MALDI-TOF MS系统，VITEK MS IVD(BioMerieux)和Microflex LT Biotyper(Bruker Daltonics)在阳性血培养中直接鉴定细菌的性能。在181个单一微生物培养中，两个系统都为90%的标本产生了从属到种的鉴定(Biotyper，177/181[97.8%]；Vitek MS IVD，167/181[92.3%])。总体而言，Biotyper系统比VITEK MS IVD系统产生的识别更准确(P=0.016；181个样本中有177个对167个)。Biotyper系统在多菌血液培养中确定了少数物种。我们还比较了内部提取方法和Sepsityper方法在两个MALDI-TOF MS系统上的性能。在Biotyper系统上，内部方法在属水平上的正确识别率(96.7%)高于Sepsityper(93.5%)，而在Vitek MS IVD系统上，两种方法的性能水平相同(88.0%对88.0%)。我们的研究证实了MALDI-TOF MS的实用优势，我们的内部提取方法将试剂成本降低到每个样本1美元，周转时间更短，为3小时，这对于诊断微生物学服务是非常划算的。
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of bacteria and fungi was recently introduced in microbiology laboratories. This technology could greatly improve the clinical management of patients and guidance for chemotherapy. In this study, we used a commercial MALDI Sepsityper extraction method to evaluate the performance of two commercial MALDI-TOF MS systems, the Vitek MS IVD (bioMerieux) and the Microflex LT Biotyper (Bruker Daltonics) for direct bacterial identification in positive blood cultures. In 181 monomicrobial cultures, both systems generated genus to species level identifications for >90% of the specimens (Biotyper, 177/181 [97.8%]; Vitek MS IVD, 167/181 [92.3%]). Overall, the Biotyper system generated significantly more accurate identifications than the Vitek MS IVD system (P = 0.016; 177 versus 167 out of 181 specimens). The Biotyper system identified the minority species among polymicrobial blood cultures. We also compared the performance of an in-house extraction method with that of the Sepsityper on both MALDI-TOF MS systems. The in-house method generated more correct identifications at the genus level than the Sepsityper (96.7% versus 93.5%) on the Biotyper system, whereas the two methods exhibited the same performance level (88.0% versus 88.0%) on the Vitek MS IVD system. Our study confirmed the practical advantages of MALDI-TOF MS, and our in-house extraction method reduced the reagent cost to $1 per specimen, with a shorter turnaround time of 3 h, which is highly cost-effective for a diagnostic microbiology service.