Identification of Brucella by MALDI-TOF mass spectrometry. Fast and reliable identification from agar plates and blood cultures

• Published in: PloS one 2010-12, Vol.5 (12), p.e14235-e14235
• Main Authors: Ferreira, Laura, Vega Castaño, Silvia, Sánchez-Juanes, Fernando, González-Cabrero, Sandra, Menegotto, Fabiola, Orduña-Domingo, Antonio, González-Buitrago, José Manuel, Muñoz-Bellido, Juan Luis
• Format: Article
• Language: English
• Subjects: Agar; Agar - chemistry; Algorithms; Automation; Bacteria; Bacterial Typing Techniques; Bacteriological Techniques - methods; Biotypes; Blood; Blood - microbiology; Blood culture; Blood tests; Brucella; Brucella - metabolism; Brucella abortus - metabolism; Brucella melitensis - metabolism; Brucellosis; Canis; Cells, Cultured; Cetacea; Clinical isolates; Culture; Desorption; Francisella tularensis; Humans; Identification; Infectious Diseases/Bacterial Infections; Ions; Laboratories; Lasers; Listeria; Mass spectrometry; Mass spectroscopy; Methods; Microbiology; Microbiology/Medical Microbiology; Microorganisms; Phylogeny; Plates; Scientific imaging; Species; Species Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Spectroscopy; Strains (organisms)
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0014235

MALDI-TOF mass spectrometry (MS) is a reliable method for bacteria identification. Some databases used for this purpose lack reference profiles for Brucella species, which is still an important pathogen in wide areas around the world. We report the creation of profiles for MALDI-TOF Biotyper 2.0 database (Bruker Daltonics, Germany) and their usefulness for identifying brucellae from culture plates and blood cultures. We created MALDI Biotyper 2.0 profiles for type strains belonging to B. melitensis biotypes 1, 2 and 3; B. abortus biotypes 1, 2, 5 and 9; B. suis, B. canis, B ceti and B. pinnipedialis. Then, 131 clinical isolates grown on plate cultures were used in triplicate to check identification. Identification at genus level was always correct, although in most cases the three replicates reported different identification at species level. Simulated blood cultures were performed with type strains belonging to the main human pathogenic species (B. melitensis, B. abortus, B. suis and B. canis), and studied by MALDI-TOF MS in triplicate. Identification at genus level was always correct. MALDI-TOF MS is reliable for Brucella identification to the genus level from culture plates and directly from blood culture bottles.