title: Multicenter evaluation of the Sepsityper™ extraction kit and MALDI-TOF MS for direct identification of positive blood culture isolates using the BD BACTEC™ FX and VersaTREK(®) diagnostic blood culture systems.
abstract: OBJECTIVE
  (i) Evaluation of delayed time to blood culture extraction by the Sepsityper kit and impact of shipping pellets off-site for MALDI-TOF MS analysis. (ii) Comparison of Sepsityper and laboratory-developed extraction methods from a literature review.
  
  
  RESULTS
  Using two blood culture systems (BD BACTEC and VersaTREK), we extracted 411 positive blood cultures using the Sepsityper kit to mimic a potential protocol for institutions without a MALDI-TOF MS. Extracted pellets were shipped and analysed on the Bruker UltraflexIII. Successful extraction of 358 (87·1%) samples was determined by the presence of detectable proteins. MALDI-TOF MS correctly identified 332 (80·8%) samples.
  
  
  CONCLUSIONS
  Delayed time to extraction did not affect Sepsityper extraction or MALDI-TOF MS accuracy. The extracted pellets remain stable and provide accurate results by MALDI-TOF MS when shipped at room temperature to off-site reference laboratories.
  
  
  CONCLUSIONS
  This is the first study to show that institutions without a MALDI-TOF MS can take advantage of this innovative technology by shipping a volume of blood to an off-site laboratory for extraction and MALDI-TOF MS analysis. We also performed a literature review to compare various extraction methods.
authors.affiliation: The Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Schieffer
authors.forename: K E
authors.initials: KE
authors.lastname: Tan
authors.forename: P D
authors.initials: PD
authors.lastname: Stamper
authors.forename: A
authors.initials: A
authors.lastname: Somogyi
authors.forename: S B
authors.initials: SB
authors.lastname: Andrea
authors.forename: T
authors.initials: T
authors.lastname: Wakefield
authors.forename: M
authors.initials: M
authors.lastname: Romagnoli
authors.forename: K C
authors.initials: KC
authors.lastname: Chapin
authors.forename: D M
authors.initials: DM
authors.lastname: Wolk
authors.forename: K C
authors.initials: KC
authors.lastname: Carroll
mesh_terms: D016470:Bacteremia / Q000175:diagnosis; D001419:Bacteria / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification; D001431:Bacteriological Techniques / Q000379:methods; D006801:Humans; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D001426:Bacterial Proteins
keywords: MALDI-TOF MS; Sepsityper; bacteraemia; blood cultures; sepsis