alexa An evaluation of three processing methods and the effect of reduced culture times for faster direct identification of pathogens from BacT ALERT blood cultures by MALDI-TOF MS.
Chemical Engineering

Chemical Engineering

Mass Spectrometry & Purification Techniques

Author(s): Loonen AJ, Jansz AR, Stalpers J, Wolffs PF, van den Brule AJ

Abstract Share this page

Abstract Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a fast and reliable method for the identification of bacteria from agar media. Direct identification from positive blood cultures should decrease the time to obtaining the result. In this study, three different processing methods for the rapid direct identification of bacteria from positive blood culture bottles were compared. In total, 101 positive aerobe BacT/ALERT bottles were included in this study. Aliquots from all bottles were used for three bacterial processing methods, i.e. the commercially available Bruker's MALDI Sepsityper kit, the commercially available Molzym's MolYsis Basic5 kit and a centrifugation/washing method. In addition, the best method was used to evaluate the possibility of MALDI application after a reduced incubation time of 7 h of Staphylococcus aureus- and Escherichia coli-spiked (1,000, 100 and 10 colony-forming units [CFU]) aerobe BacT/ALERT blood cultures. Sixty-six (65\%), 51 (50.5\%) and 79 (78\%) bottles were identified correctly at the species level when the centrifugation/washing method, MolYsis Basic 5 and Sepsityper were used, respectively. Incorrect identification was obtained in 35 (35\%), 50 (49.5\%) and 22 (22\%) bottles, respectively. Gram-positive cocci were correctly identified in 33/52 (64\%) of the cases. However, Gram-negative rods showed a correct identification in 45/47 (96\%) of all bottles when the Sepsityper kit was used. Seven hours of pre-incubation of S. aureus- and E. coli-spiked aerobe BacT/ALERT blood cultures never resulted in reliable identification with MALDI-TOF MS. Sepsityper is superior for the direct identification of microorganisms from aerobe BacT/ALERT bottles. Gram-negative pathogens show better results compared to Gram-positive bacteria. Reduced incubation followed by MALDI-TOF MS did not result in faster reliable identification.
This article was published in Eur J Clin Microbiol Infect Dis and referenced in Mass Spectrometry & Purification Techniques

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version