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Title of article :
Strain and phase identification of the U.S. category B agent Coxiella burnetii by matrix assisted laser desorption/ionization time-of-flight mass spectrometry and multivariate pattern recognition Original Research Article
Author/Authors :
Carrie Y. Pierce، نويسنده , , John R. Barr، نويسنده , , Adrian R. Woolfitt، نويسنده , , Hercules Moura، نويسنده , , Edward I. Shaw، نويسنده , , Herbert A. Thompson، نويسنده , , Robert F. Massung، نويسنده , , Facundo M. Fernandez، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
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Abstract :
Accurate bacterial identification is important in diagnosing disease and in microbial forensics. Coxiella burnetii, a highly infective microorganism causative of the human disease Q fever, is now considered a U.S. category B potential bioterrorism agent. We report here an approach for the confirmatory identification of C. burnetii at the strain level which involves the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and supervised pattern recognition via Partial Least Squares-Discriminant Analysis (PLS-DA). C. burnetii isolates investigated in this study included the following prototype strains from different geographical and/or historical origins and with different antigenic properties: Nine Mile I, Australian QD, M44, KAV, PAV, Henzerling, and Ohio. After culture and purification following standard protocols, linear MALDI-TOF mass spectra of pure bacterial cultures were acquired in positive ion mode. Mass spectral data were normalized, baseline-corrected, denoised, binarized and modeled by PLS-DA under crossvalidation conditions. Robustness with respect to uncontrolled variations in the sample preparation and MALDI analysis protocol was assessed by repeating the experiment on five different days spanning a period of 6 months. The method was validated by the prediction of unknown C. burnetii samples in an independent test set with 100% sensitivity and specificity for five out of six strain classes.
Keywords :
Partial least squares discriminant analysis , Coxiella burnetii , Time-of-flight mass spectrometry , Matrix-assisted laser desorption/ionization , Microorganism identification
Journal title :
Analytica Chimica Acta
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