MALDI Biotyper, experience in routine clinical bacteriology in a university hospital

Abstract number: P1775

Bessede E., Angla-Gré M., Delagarde Y., Sep Hieng S., Menard A., Megraud F.

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) appears to have the potential to replace conventional techniques in a routine bacteriology laboratory. Its performance still needs to be evaluated on a large scale. Our aim was to compare MALDI-Biotyper identification of bacteria to the conventional phenotypic identification in a large University Hospital Bacteriology laboratory.

Methods: A prospective study was carried out from April to May 2009. Bacterial isolates from clinical samples were identified by conventional phenotypic bacteriological methods (Phoenix, Beckton Dickinson & Api strips, bioMérieux) and in parallel with a mass spectrometer (Ultraflex III TOF/TOF, Bruker Daltonics, Germany). In case of discrepancy between these results at the genus level, a 16S rRNA and /or rpoB gene sequencing was performed.

Results: Of the 1,013 bacteria tested, 98% were correctly identified at the genus level by the MALDI Biotyper vs. 97% with the conventional methods.

The majority of bacteria could be identified without the step of extraction and gave a score >2. It was even possible to correctly identify bacteria with a score slightly lower that 2 when there was matching with the same species profile several times.

The limits of MALDI Biotyper concerned some Acinetobacter species (4 times), rare species not yet in the data basis (6 times) and at this stage the subspeciation for Salmonella enterica.

Conclusion: The MALDI Biotyper allowed an accurate identification of bacteria, much quicker than conventional phenotypic methods. The integration of this identification method with the antimicrobial testing remains the challenge for the future.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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