Direct Identification of 80 Percent of Bacteria from Blood Culture Bottles by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Using a 10-Minute Extraction Protocol
Direct Identification of 80 Percent of Bacteria from Blood Culture Bottles by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Using a 10-Minute Extraction Protocol
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DOI：
10.1128/jcm.01278-18
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发表时间：
2019-02-01
影响因子：
9.4
通讯作者：
Ruimy, Raymond
中科院分区：
文献类型：
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作者：
Simon, Loic;Ughetto, Estelle;Ruimy, Raymond
由于实验流程过长，基质辅助激光解吸电离飞行时间质谱法并未广泛用于直接从阳性血培养瓶 (BCB) 中鉴定细菌。这项工作的目的是开发和评估一种简单的提取方案，以便从 BCB 中进行可靠的鉴定。 10 分钟方案应用了 5 个月。将第 0 天的直接识别结果与第 1 天从菌落获得的结果进行比较 [log(score) of >= 2]。我们在第 0 天评估了从 1.4 到 2.0 的七个日志（分数）阈值，以找到较低的置信度分数，该分数可提供更高百分比的直接识别而不损失准确性。第 0 天的 log（分数）阈值 >= 1.5 时，我们的协议允许我们识别 632 个 BCB 中 80% 的细菌（96% 肠杆菌科、95% 金黄色葡萄球菌、92% 肠球菌和 62% 链球菌）。在 77% 的多种微生物样品中至少鉴定出了混合物中的一种细菌种类。该方案的快速性和可靠性是其常规使用的因素，使我们能够在识别 BCBs C 中 80% 的细菌方面节省长达 24 小时的时间，从而在必要时提供有用的信息来调整抗生素治疗。目前，我们每天提供可靠的葡萄球菌、肠球菌、肠杆菌科、铜绿假单胞菌和β-溶血性链球菌的直接鉴定。
Matrix-assisted laser desorption ionization-time of flight mass spectrometry is not widely used to identify bacteria directly from positive blood culture bottles (BCBs) because of overlong protocols. The objective of this work was to develop and evaluate a simple extraction protocol for reliable identification from BCBs. The 10-min protocol was applied over a 5-month period. Direct identifications on day 0 were compared with those obtained from colonies on day 1 [log(score) of >= 2]. We evaluated a range of seven log(score) thresholds on day 0 from 1.4 to 2.0 to find the lower confidence score that provides the higher percentage of direct identifications without loss of accuracy. With a log(score) threshold of >= 1.5 at day 0, our protocol allowed us to identify 80% of bacteria in 632 BCBs (96% of Enterobacteriaceae, 95% of Staphylococcus aureus, 92% of enterococci, and 62% of streptococci). At least one bacterial species of the mixture was identified in 77% of the polymicrobial samples. The rapidity and reliability of the protocol were factors in its adoption for routine use, allowing us to save up to 24 h in identifying 80% of the bacteria in the BCBs C and, thus, to supply useful information to adapt antibiotic therapy when necessary. We currently provide reliable daily direct identifications of staphylococci, entero- cocci, Enterobacteriaceae, Pseudomonas aeruginosa, and beta-hemolytic streptococci.