Rapid Identification of Bacteria and Yeasts from Positive-Blood-Culture Bottles by Using a Lysis-Filtration Method and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrum Analysis with the SARAMIS Database
Rapid Identification of Bacteria and Yeasts from Positive-Blood-Culture Bottles by Using a Lysis-Filtration Method and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrum Analysis with the SARAMIS Database
复制标题
DOI：
10.1128/jcm.02326-12
复制
发表时间：
2013-03-01
影响因子：
9.4
通讯作者：
Wang, Yun F. (Wayne)
中科院分区：
文献类型：
--
作者：
Fothergill, Amy;Kasinathan, Vyjayanti;Wang, Yun F. (Wayne)
直接从阳性血培养中快速鉴定引起血流感染的微生物将减少定向抗菌治疗的时间，并大大改善患者护理。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）是一种快速、可靠的鉴定阳性培养物中微生物的方法。本研究评价了一种基于过滤的新型方法的性能，该方法用于处理阳性血培养肉汤，以通过MALDI-TOF和Vitek MS研究专用系统（VMS）立即鉴定微生物。包括BacT/Alert 3D系统标记为阳性的BacT/Alert非活性炭血培养瓶。将等份阳性血培养肉汤与裂解缓冲液在室温下孵育2至4 min，将所得裂解物通过膜过滤，并通过VMS鉴定收获的微生物。在本研究纳入的259个培养瓶中，VMS将189个（73%）培养物中的微生物鉴定为种属水平，51个（19.7%）培养物未给出鉴定（ID），而6个（2.3%）培养物给出的鉴定被认为不正确。在来自阳性血培养瓶的131株单微生物分离株中，其中一个斑点的得分为99.9%，131株（100%）的ID正确到种属水平。在VMS能够生成ID的202个培养瓶中，189个（93.6%）的ID在种属水平上正确，而7个分离株（3.5%）的ID不正确。总之，该方法不需要离心，并在不到15分钟的时间内产生用于VMS分析的干净光谱。本研究证明了新的裂解-过滤方法在临床环境中直接从阳性血培养瓶中识别微生物的有效性。
Rapid identification of microorganisms causing bloodstream infections directly from a positive blood culture would decrease the time to directed antimicrobial therapy and greatly improve patient care. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable method for identifying microorganisms from positive culture. This study evaluates the performance of a novel filtration-based method for processing positive-blood-culture broth for immediate identification of microorganisms by MALDI-TOF with a Vitek MS research-use-only system (VMS). BacT/Alert non-charcoal-based blood culture bottles that were flagged positive by the BacT/Alert 3D system were included. An aliquot of positive-blood-culture broth was incubated with lysis buffer for 2 to 4 min at room temperature, the resulting lysate was filtered through a membrane, and harvested microorganisms were identified by VMS. Of the 259 bottles included in the study, VMS identified the organisms in 189 (73%) cultures to the species level and 51 (19.7%) gave no identification (ID), while 6 (2.3%) gave identifications that were considered incorrect. Among 131 monomicrobic isolates from positive-blood-culture bottles with one spot having a score of 99.9%, the IDs for 131 (100%) were correct to the species level. In 202 bottles where VMS was able to generate an ID, the IDs for 189 (93.6%) were correct to the species level, whereas the IDs provided for 7 isolates (3.5%) were incorrect. In conclusion, this method does not require centrifugation and produces a clean spectrum for VMS analysis in less than 15 min. This study demonstrates the effectiveness of the new lysis-filtration method for identifying microorganisms directly from positive-blood-culture bottles in a clinical setting.