A comparative study of two different methods of sample preparation for positive blood cultures for the rapid identification of bacteria using MALDI-TOF MS

Eur J Clin Microbiol Infect Dis. 2012 Jul;31(7):1353-8. doi: 10.1007/s10096-011-1449-x. Epub 2011 Oct 26.

Abstract

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has lately been implemented as a solid technology for rapid microorganism identification in microbiology laboratories. This study compares two methods for bacterial separation from 85 positive blood culture before MALDI-TOF MS: (1) a conventional method that we used in our laboratory to prepare bacteria for susceptibility testing and (2) a new commercialized technique (Sepsityper). There were no significant differences in the identification of Gram-negative bacilli regardless of the bacterial separation method used. However, identification was greater for Gram-positive cocci when the Sepsityper method was used (84.15% vs. 100% in the identification to a genus level in staphylococci and 57.14% vs. 85.71% in the identification to a genus level of enterococci with the in-house and Sepsityper methods, respectively). Therefore, the Sepsityper method to prepare bacteria from a positive blood culture is more adequate for the further identification of Gram-positive cocci by MALDI-TOF MS.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteremia / diagnosis*
  • Bacteria / classification*
  • Bacteria / isolation & purification*
  • Bacteriological Techniques / methods*
  • Blood / microbiology*
  • Humans
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*