Guembe María, Rodríguez-Sánchez Belén, Ruiz Adrián, Martín-Rabadán Pablo, Rodríguez-Créixems Marta, Bouza Emilio
Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Enferm Infecc Microbiol Clin. 2014 Jun-Jul;32(6):372-4. doi: 10.1016/j.eimc.2014.01.011. Epub 2014 Mar 26.
The use of the matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry has shown to be effective and fast in some clinical specimens for the identification of colonizing microorganisms. The objective of the study was to analyze the validity values for the prediction of colonization and catheter-related bloodstream infection (C-RBSI) of the MALDI-TOF mass spectrometry performed at all intravascular catheters that arrived in the microbiology laboratory.
Catheter tips (after performing the roll-plate technique) were tested by MALDI-TOF mass spectrometry during a period of 3-months. The gold standard for colonization and C-RBSI were, respectively: the presence of ≥15cfu/plate in the catheter tip culture; and the isolation of the same microorganism(s) in blood cultures as well as in the colonized catheter (during the 7days before or after catheter withdrawal).
A total of 182 intravascular catheters were collected. The overall colonization rate detected by roll-plate technique and MAL-TOF mass spectrometry was 31.9% and 32.4%, respectively. Overall, there were 33 (18.1%) episodes of C-RBSI. The validity values of the MALDI-TOF mass spectrometry for the identification of colonization and C-RBSI were, respectively: sensitivity (69.0%/66.7%), specificity (84.7%/75.2%), positive predictive value (65.6%/36.1%), and negative predictive value (86.8%/92.6%). Conclusion MALDI-TOF mass spectrometry could be an alternative diagnostic tool for ruling out C-RBSI. However, despite it showing to be faster than conventional culture, future studies are required in order to improve the pre-analytical process.
基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱法已被证明在一些临床标本中用于鉴定定植微生物是有效且快速的。本研究的目的是分析在微生物实验室收到的所有血管内导管上进行的MALDI-TOF质谱法对预测定植和导管相关血流感染（C-RBSI）的有效性值。
在3个月的时间内，通过MALDI-TOF质谱法对导管尖端（采用滚板技术后）进行检测。定植和C-RBSI的金标准分别为：导管尖端培养物中≥15cfu/平板；以及在血培养和定植导管（在拔管前或后7天内）中分离出相同的微生物。
共收集了182根血管内导管。通过滚板技术和MAL-TOF质谱法检测到的总体定植率分别为31.9%和32.4%。总体而言，有33例（18.1%）C-RBSI事件。MALDI-TOF质谱法对鉴定定植和C-RBSI的有效性值分别为：敏感性（69.0%/66.7%）、特异性（84.7%/75.2%）、阳性预测值（65.6%/36.1%）和阴性预测值（86.8%/92.6%）。结论MALDI-TOF质谱法可能是排除C-RBSI的一种替代诊断工具。然而，尽管它比传统培养更快，但仍需要进一步研究以改善分析前过程。
