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Detection of highly pathogenic bacteria by MALDITOFMS

Abstract number: P1773

Blaschitz M., Meidlinger L., Sagel U., Wewalka G., Allerberger F., Indra A.

Objectives: Highly pathogenic bacteria both acquired by natural infection or after deliberate dissemination cause severe diseases in humans, thus their fast identification is of paramount importance. Matrix-Assisted Laser Desorption Ionisation Time-of-Flight Mass Spectrometry (MALDI TOF MS) represents a rapid tool for the species specific identification of microorganisms due to ribosomal protein profiles by mass spectrometry.

Methods:Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucella spp., Burkholderia mallei and B. pseudomallei were cultivated under Biosafety Level (BSL) 3 conditions. Colonies were picked, inactivated and subsequently tested for survival. Ribosomal proteins were extracted from killed cells and measured by the microflex™ LT MALDI-TOF system. Data were analysed using the Bruker Daltonics Maldi Biotyper 2.0 and Flex Analysis 3.0 software and the reference library 3.0.

Results: The reference library 3.0 had the following entries available: Bacillus: 109 species, Yersinia: 11 species, Francisella: 0, Brucella: 0, Burkholderia: 25 species. Of 14 samples measured, all except for the Francisella- and Brucella samples were correctly identified at the genus level by the microflex™ LT system. B. anthracis was identified as probable B. cereus, Y. pestis was identified as probable Y. pseudotuberculosis and B. mallei and pseudomallei were both identified as probable B. thailandensis species.

Conclusion: For an accurate identification of highly pathogenic bacteria by MALDI TOF the MALDI Biotyper Security Library would have been an optimal choice as it comprises reference mass spectra of respective bacteria. However, the present study demonstrates that highly pathogenic bacteria are definitely not identified as any other not highly pathogenic microorganism by the microflex™ LT MALDI-TOF system. Since sample cultivation is required prior to a MALDI TOF measurement, prompt DNA isolation from sample material and subsequent real-time PCR currently represent the fastest and most reliable methods for the identification of highly pathogenic bacteria.

Session Details

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