Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.
Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.
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DOI：
10.1371/journal.pone.0008041
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发表时间：
2009-11-25
期刊：
影响因子：
3.7
通讯作者：
Raoult D
中科院分区：
文献类型：
--
作者：
La Scola B;Raoult D
由于在取样和获得结果之间观察到长时间的延迟，血培养在紧急传染病情况下的有用性最近受到质疑。在允许从生长的菌落中更快地鉴定细菌的方法中，基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱法被证明可以准确地鉴定临床生物学实验室中常规分离的细菌。为了加快鉴定过程，在本工作中，我们尝试直接从自动检测阳性的血培养瓶中进行细菌鉴定。我们前瞻性地分析了常规MALDI-TOF鉴定血培养中检测到的细菌，通过两种不同的方案，包括连续离心，然后用三氟乙酸或甲酸裂解。在562份经自动化检测为阳性且含有一种细菌的血培养肉汤中，370份（66%）被正确鉴定。将方案从三氟乙酸变更为甲酸改善了葡萄球菌的鉴定，总体正确鉴定率从59%提高到76%。大多数情况下对草绿色链球菌缺乏识别，仅观察到1例假阳性。在22份含有两种或两种以上不同菌种的阳性血培养液中，18份样本中仅鉴定出一种菌种，2份样本中未鉴定出菌种，2份样本中获得错误菌种鉴定。细菌鉴定的阳性预测值为99.2%。MALDI-TOF MS是直接常规鉴定血培养中细菌分离株的有效方法，但多种微生物样本和草绿色链球菌除外。如果在不久的将来能提高培养草绿色链球菌的血培养肉汤的特异性，它可能取代对菌落进行的常规鉴定。
With long delays observed between sampling and availability of results, the usefulness of blood cultures in the context of emergency infectious diseases has recently been questioned. Among methods that allow quicker bacterial identification from growing colonies, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry was demonstrated to accurately identify bacteria routinely isolated in a clinical biology laboratory. In order to speed up the identification process, in the present work we attempted bacterial identification directly from blood culture bottles detected positive by the automate. We prospectively analysed routine MALDI-TOF identification of bacteria detected in blood culture by two different protocols involving successive centrifugations and then lysis by trifluoroacetic acid or formic acid. Of the 562 blood culture broths detected as positive by the automate and containing one bacterial species, 370 (66%) were correctly identified. Changing the protocol from trifluoroacetic acid to formic acid improved identification of Staphylococci, and overall correct identification increased from 59% to 76%. Lack of identification was observed mostly with viridans streptococci, and only one false positive was observed. In the 22 positive blood culture broths that contained two or more different species, only one of the species was identified in 18 samples, no species were identified in two samples and false species identifications were obtained in two cases. The positive predictive value of bacterial identification using this procedure was 99.2%. MALDI-TOF MS is an efficient method for direct routine identification of bacterial isolates in blood culture, with the exception of polymicrobial samples and viridans streptococci. It may replace routine identification performed on colonies, provided improvement for the specificity of blood culture broths growing viridans streptococci is obtained in the near future.
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影响因子：
3.1
作者：
Corbo, J;Friedman, B;Gallagher, EJ
通讯作者：
Gallagher, EJ
影响因子：
4.3
作者：
Camara, Johanna E.;Hays, Faith A.
通讯作者：
Hays, Faith A.
影响因子：
14.2
作者：
Westh, H.;Lisby, G.;Hoeft, A.
通讯作者：
Hoeft, A.
影响因子：
9.4
作者：
COYLE, MB;MCGONAGLE, LA;SCHOENKNECHT, FD
通讯作者：
SCHOENKNECHT, FD
影响因子：
9.4
作者：
Eigner, U;Weizenegger, M;Witte, W
通讯作者：
Witte, W