title: Proteogenomic biomarkers for identification of Francisella species and subspecies by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry.
abstract: Francisella tularensis is the causative agent of tularemia. Because some Francisella strains are very virulent, this species is considered by the Centers for Disease Control and Prevention to be a potential category A bioweapon. A mass spectrometry method to quickly and robustly distinguish between virulent and nonvirulent Francisella strains is desirable. A combination of shotgun proteomics and whole-cell matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry on the Francisella tularensis subsp. holarctica LVS defined three protein biomarkers that allow such discrimination: the histone-like protein HU form B, the 10 kDa chaperonin Cpn10, and the 50S ribosomal protein L24. We established that their combined detection by whole-cell MALDI-TOF spectrum could enable (i) the identification of Francisella species, and (ii) the prediction of their virulence level, i.e., gain of a taxonomical level with the identification of Francisella tularensis subspecies. The detection of these biomarkers by MALDI-TOF mass spectrometry is straightforward because of their abundance and the absence of other abundant protein species closely related in terms of m/z. The predicted molecular weights for the three biomarkers and their presence as intense peaks were confirmed with MALDI-TOF/MS spectra acquired on Francisella philomiragia ATCC 25015 and on Francisella tularensis subsp. tularensis CCUG 2112, the most virulent Francisella subspecies.
authors.affiliation: CEA Marcoule , DSV, IBEB, Laboratoire de Biochimie des Systèmes Perturbés, Bagnols-sur-Cèze, F-30207, France.
authors.forename: Emie
authors.initials: E
authors.lastname: Durighello
authors.forename: Laurent
authors.initials: L
authors.lastname: Bellanger
authors.forename: Eric
authors.initials: E
authors.lastname: Ezan
authors.forename: Jean
authors.initials: J
authors.lastname: Armengaud
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism; D015373:Bacterial Typing Techniques / Q000295:instrumentation / Q000379:methods*; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D023482:Bioterrorism / Q000517:prevention & control; D004268:DNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D005604:Francisella tularensis / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D018832:Molecular Chaperones / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D040901:Proteomics / Q000295:instrumentation / Q000379:methods*; D012269:Ribosomal Proteins / Q000302:isolation & purification* / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014406:Tularemia / Q000175:diagnosis; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D015415:Biomarkers; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; D012269:Ribosomal Proteins; C040330:histone-like protein HU, bacteria; C036298:ribosomal protein L24