title: Can MALDI-TOF mass spectrometry be used with intravascular catheters?
abstract: BACKGROUND
  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.
  
  
  METHODS
  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).
  
  
  RESULTS
  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.
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain. Electronic address: mariaguembe@hotmail.com.
authors.forename: María
authors.initials: M
authors.lastname: Guembe
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Rodríguez-Sánchez
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Adrián
authors.initials: A
authors.lastname: Ruiz
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín-Rabadán
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Rodríguez-Créixems
authors.affiliation: Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Bouza
mesh_terms: D055499:Catheter-Related Infections / Q000382:microbiology*; D004866:Equipment Contamination / Q000517:prevention & control*; D006801:Humans; D011237:Predictive Value of Tests; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D062666:Vascular Access Devices / Q000382:microbiology*
keywords: Bacteriemia relacionada con el catéter; Catheter-related bloodstream infection; Catéteres intravasculares; Colonización; Colonization; Conventional culture; Cultivo convencional; Espectrometría de masas MALDI-TOF; Intravascular catheters; MALDI-TOF mass spectrometry