title: Identification of Gallibacterium species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry evaluated by multilocus sequence analysis.
abstract: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) whole-cell fingerprinting was used for characterization of 66 reference strains of Gallibacterium. The 4 recognised Gallibacterium species and Gallibacterium genomospecies 1 yielded reproducible and unique mass spectrum profiles, which were confirmed with Bruker Biotyper reference database version 3. The reproducibility of MALDI-TOF MS results were evaluated varying the age and storage of the cultures investigated. Reliable species identification was possible for up to 8 days of storage at 4°C and less reliable if the bacteria were stored at room temperature (20°C). However, if the strains were grown longer than 48h at 37°C under microaerobic atmosphere, poor identification results were obtained, due to changes in protein profile. The MALDI-TOF MS results of all 66 strains demonstrated 87.9% concordance with results based upon biochemical/physiological characterization. In addition, diversities outlined by MALDI-TOF MS were verified by sequencing the rpoB (n=43), 16S rRNA (n=28), infB (n=14), and recN (n=14) genes (multilocus sequence analysis, MLSA). In addition, discrepancies were observed between some of the genes sequenced. Results obtained demonstrated that MALDI-TOF MS fingerprinting represents a fast and reliable method for identification and differentiation of the 4 recognised Gallibacterium species and possible a fifth species Gallibacterium genomospecies 1, with applications in clinical diagnostics.
authors: Clinic for Avian, Reptile and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria. merima.alispahic@vetmeduni.ac.at
authors: Merima
authors: M
authors: Alispahic
authors: Henrik
authors: H
authors: Christensen
authors: Claudia
authors: C
authors: Hess
authors: Ebrahim
authors: E
authors: Razzazi-Fazeli
authors: Magne
authors: M
authors: Bisgaard
authors: Michael
authors: M
authors: Hess