Enhanced specificity of bacterial spore identification by oxidation and mass spectrometry

Demirev, Plamen A.

doi:10.1002/rcm.1680

Cited by 10 publications

(12 citation statements)

References 36 publications

(39 reference statements)

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“…In proteins, the amino acid methionine and aromatic residues like tryptophan and tyrosine are potential first oxidation targets (45,46). In the case of oxidation of methionine, the experimentally observed mass differences between the parent and satellite peaks of 16 Da would fit well with the computed masses of unoxidized methionine and methionine sulfoxide as the singly oxidized species (47). However, the mass differences mentioned would be also observable in the case of oxidation of other amino acids.…”

Section: Fig 2 Oxidation Ofmentioning

confidence: 59%

Identification of Highly Pathogenic Microorganisms by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Results of an Interlaboratory Ring Trial

et al. 2015

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mIn the case of a release of highly pathogenic bacteria (HPB), there is an urgent need for rapid, accurate, and reliable diagnostics. MALDI-TOF mass spectrometry is a rapid, accurate, and relatively inexpensive technique that is becoming increasingly important in microbiological diagnostics to complement classical microbiology, PCR, and genotyping of HPB. In the present study, the results of a joint exercise with 11 partner institutions from nine European countries are presented. In this exercise, 10 distinct microbial samples, among them five HPB, Bacillus anthracis, Brucella canis, Burkholderia mallei, Burkholderia pseudomallei, and Yersinia pestis, were characterized under blinded conditions. Microbial strains were inactivated by high-dose gamma irradiation before shipment. Preparatory investigations ensured that this type of inactivation induced only subtle spectral changes with negligible influence on the quality of the diagnosis. Furthermore, pilot tests on nonpathogenic strains were systematically conducted to ensure the suitability of sample preparation and to optimize and standardize the workflow for microbial identification. The analysis of the microbial mass spectra was carried out by the individual laboratories on the basis of spectral libraries available on site. All mass spectra were also tested against an in-house HPB library at the Robert Koch Institute (RKI). The averaged identification accuracy was 77% in the first case and improved to >93% when the spectral diagnoses were obtained on the basis of the RKI library. The compilation of complete and comprehensive databases with spectra from a broad strain collection is therefore considered of paramount importance for accurate microbial identification. Highly pathogenic bacteria (HPB) are risk group 3 bacteria, which are defined as biological agents that can cause severe human disease and present a serious hazard to health care workers. This may present a risk of spreading to the community, but there is usually effective prophylaxis or treatment available (1). To this group belong bacteria such as Bacillus anthracis, Francisella tularensis subsp. tularensis (type A), Yersinia pestis, species of the Brucella melitensis group, Burkholderia mallei, and Burkholderia pseudomallei. HPB have the potential to be used in bioterrorist attacks (2, 3). The Centers for Disease Control and Prevention (CDC, Atlanta, GA) have classified B. anthracis, F. tularensis, and Y. pestis as category A and Brucella species, B. mallei, B. pseudomallei, and Coxiella burnetii as category B, comprising the main pathogens of concern for use in bioterrorist attacks (4). These pathogens may cause anthrax, tularemia, plague, brucellosis, glanders, melioidosis, and Q fever, respectively. In most parts of the world, the natural prevalence of these agents is low, even though some of these agents cause outbreaks in human and animal populations from time to time (5-8). The intentional release of these agents, however, can result in severe public health consequences, as was shown in the U...

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Section: Fig 2 Oxidation Ofmentioning

confidence: 59%

Identification of Highly Pathogenic Microorganisms by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Results of an Interlaboratory Ring Trial

et al. 2015

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“…Treatment of the sample with sodium iodide prior to matrix addition was found to improve the ionization of phospholipids from cell walls of selected Enterobacteriaceae (Ishida et al, 2002). On-target oxidation of proteins from bacillus spores with 30% hydrogen peroxide resulted in the possibility to confirm the identity of the detected compounds via the detection of a þ16 Da mass shift corresponding to methionine oxidation (Demirev, 2004). On-target treatment of bacillus spores with 10% TFA with the aim of small acid-soluble proteins extraction was employed by followed by others.…”

Section: G On-target Sample Treatmentmentioning

confidence: 99%

“…Supervised data treatment approaches were often required for distinguishing the subtle differences between the MALDI-MS profiles of different strains. The principles and algorithms of these approaches have been reviewed elsewhere (Fenselau & Demirev, 2001;Demirev et al, 2004;Dworzanski & Snyder, 2005;Fenselau & Demirev, 2008b).…”

Section: Maldi-ms Profiling Of Bacteriamentioning

confidence: 99%

Sample preparation methods for MALDI‐MS profiling of bacteria

Šedo¹,

Sedláček²,

Zdráhal³

2010

Mass Spectrometry Reviews

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Direct matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) bacterial cell or lysate analysis appears to meet all the criteria required for a rapid and reliable analytical microorganism identification and taxonomical classification tool. Few-minute analytical procedure providing information extending up to sub-species level underlines the potential of the MALDI-MS profiling in comparison with other methods employed in the field. However, the quality of MALDI-MS profiles and consequently the performance of the method are influenced by numerous factors, which involve particular steps of the sample preparation procedure. This review is aimed at advances in development and optimization of the MALDI-MS profiling methodology. Approaches improving the quality of the MALDI-MS profiles and universal feasibility of the method are discussed.

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“…for Campylobacter 109 and Lactobacillus 110 species. A bioinformatics‐based tool has been developed to introduce additional constraints on candidate protein biomarkers by determining the number of methionin residues in a sequence from the mass shifts before and after rapid in situ sample oxidation 111. Hypothesis testing to quantify the significance of microorganism identifications significantly improves this method 106.…”

Section: Ms Proteomics Approaches In Biodefensementioning

confidence: 99%

Mass spectrometry in biodefense

Demirev

Fenselau

2008

J. Mass Spectrom.

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Potential agents for biological attacks include both microorganisms and toxins. In mass spectrometry (MS), rapid identification of potential bioagents is achieved by detecting the masses of unique biomarkers, correlated to each agent. Currently, proteins are the most reliable biomarkers for detection and characterization of both microorganisms and toxins, and MS-based proteomics is particularly well suited for biodefense applications. Confident identification of an organism can be achieved by top-down proteomics following identification of individual protein biomarkers from their tandem mass spectra. In bottom-up proteomics, rapid digestion of intact protein biomarkers is again followed by MS/MS to provide unambiguous bioagent identification and characterization. Bioinformatics obviates the need for culturing and rigorous control of experimental variables to create and use MS fingerprint libraries for various classes of bioweapons. For specific applications, MS methods, instruments and algorithms have also been developed for identification based on biomarkers other than proteins and peptides.

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Enhanced specificity of bacterial spore identification by oxidation and mass spectrometry

Cited by 10 publications

References 36 publications

Identification of Highly Pathogenic Microorganisms by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Results of an Interlaboratory Ring Trial

Identification of Highly Pathogenic Microorganisms by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Results of an Interlaboratory Ring Trial

Sample preparation methods for MALDI‐MS profiling of bacteria

Mass spectrometry in biodefense

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