Bacterial rapid identification with matrix assisted laser desorption/ionization time-of-flight mass spectrometry: development of an 'in-house method' and comparison with Bruker Sepsityper® kit. Issue 5 (3rd September 2015)

• Record Type: Journal Article
• Authors: Fre´de´ric, S.; Antoine, M.; Bodson, A.; Lissoir, B.
• Is Part Of: Acta clinica belgica. Volume 70:Issue 5(2015)
• Page Start: 325
• Page End: 330
• Publication Date: 2015-09-03
• Subjects: Microbiology -- MALDI-TOF -- Bacteriology -- Medical laboratory -- Rapid identification -- Matrix-assisted laser desorption ionization -- Direct identification -- Bacteria -- Bacterial -- Sepsityper; Clinical medicine -- Periodicals; Diagnosis, Laboratory -- Periodicals; 616.005
• DOI: 10.1179/2295333715Y.0000000026
• Languages: English
• ISSNs: 1784-3286

Abstract

Abstract : Objective: The objective of this study was to compare an in-house matrix-assisted laser desorption ionization with time of flight (MALDI-TOF) method and a commercial MALDI-TOF kit (Sepsityper ® kit) for direct bacterial identification in positive blood cultures. We also evaluated the time saved and the cost associated with the rapid identification techniques. Methods: We used the BACTEC ® automated system for detecting positive blood cultures. Direct identification using Sepsityper kit and the in-house method were compared with conventional identification by MALDI-TOF using pure bacterial culture on the solid phase. We also evaluated different cut-off scores for rapid bacterial identification. Results: In total, 127 positive blood vials were selected. The rate of rapid identification with the MALDI Sepsityper kit was 25.2% with the standard cut-off and 33.9% with the enlarged cut-off, while the results for the in-house method were 44.1 and 61.4%, respectively. Error rates with the enlarged cut-off were 6.98 ( n = 3) and 2.56% ( n = 2) for Sepsityper and the in-house method, respectively. Identification rates were higher for gram-negative bacteria. Discussion: Direct bacterial identification succeeded in supplying rapid identification of the causative organism in cases of sepsis. The time taken to obtain a result was nearly 24 hours shorter for the direct bacterial identification methods than for conventional MALDI-TOF on solid phase culture. Compared with the Sepsityper kit, the in-house method offered better results and fewer errors, was more cost-effective and easier to use.