Abstract Acinetobacter baumannii belongs to the Acinetobacter calcoaceticus – baumannii complex (Acb) containing 2 other pathogenic species: Acinetobacter pittii and Acinetobacter nosocomialis . ...Identification of these bacteria remains problematic despite the use of matrix-assisted laser ionization time-of-flight mass spectrometry (MALDI-TOF MS). Here, we enriched the SARAMIS™ database of the Vitek MS® plus mass spectrometer to improve the identification of species of the Acb complex. For each species, we incremented reference spectra. Then, a SuperSpectrum was created based on the selection of 40 specific masses. In a second step, we validated reference spectra and SuperSpectra with 100 isolates identified by rpo B gene sequencing. All the isolates were correctly identified by MALDI-TOF MS with the database we created as compared to the identifications obtained by rpo B sequencing. Our database enabled rapid and reliable identification of the pathogen species belonging to the Acb complex. Identification by MALDI-TOF MS with our database is a good alternative to molecular biology.
