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Multicenter evaluation of the S epsityper™ extraction kit and MALDI ‐ TOF MS for direct identification of positive blood culture isolates using the BD BACTEC ™ FX and Versa TREK ® diagnostic blood culture systems
Author(s) -
Schieffer K.M.,
Tan K.E.,
Stamper P.D.,
Somogyi A.,
Andrea S.B.,
Wakefield T.,
Romagnoli M.,
Chapin K.C.,
Wolk D.M.,
Carroll K.C.
Publication year - 2014
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12434
Subject(s) - chromatography , extraction (chemistry) , blood culture , sample preparation , matrix assisted laser desorption/ionization , mass spectrometry , chemistry , biochemistry , antibiotics , organic chemistry , adsorption , desorption
Aims (i) Evaluation of delayed time to blood culture extraction by the S epsityper kit and impact of shipping pellets off‐site for MALDI ‐ TOF MS analysis. (ii) Comparison of S epsityper and laboratory‐developed extraction methods from a literature review. Methods and Results Using two blood culture systems ( BD BACTEC and Versa TREK ), we extracted 411 positive blood cultures using the S epsityper kit to mimic a potential protocol for institutions without a MALDI ‐ TOF MS . Extracted pellets were shipped and analysed on the B ruker U ltraflex III . 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 S epsityper 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.