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
Article first published online: 8 FEB 2014
© 2014 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 116, Issue 4, pages 934–941, April 2014
How to Cite
Schieffer, K.M., Tan, K.E., Stamper, P.D., Somogyi, A., Andrea, S.B., Wakefield, T., Romagnoli, M., Chapin, K.C., Wolk, D.M. and Carroll, K.C. (2014), 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. Journal of Applied Microbiology, 116: 934–941. doi: 10.1111/jam.12434
- Issue published online: 17 MAR 2014
- Article first published online: 8 FEB 2014
- Accepted manuscript online: 10 JAN 2014 09:02AM EST
- Manuscript Accepted: 31 DEC 2013
- Manuscript Revised: 17 DEC 2013
- Manuscript Received: 18 OCT 2013
- BD Diagnostics
- TREK Diagnostics
- blood cultures;
- MALDI-TOF MS;
(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.
Methods and 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.
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.
Significance and Impact of the Study
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.