In all of the loci, the differences in the number of repeats were weighted equally

because at one locus, multiple tandem repeats can be incorporated during one recombination event. The publicly available MLVA database for Brucella (MLVA-NET for Brucella, http://​mlva.​u-psud.​fr/​brucella/​) was used to identify or confirm the identity of all of the isolates used in this study. The comparison between the caliper data and MLVA bank showed some discrepancies for the allelic sequences that were obtained using different electrophoretic techniques. Due to the different nature of the gel matrix, these differences were resolved by sequencing [18, 30]. Culture conditions and sample preparation for MALDI-TOF-MS analysis From a frozen stock, the bacteria were cultured on blood agar plates for at least 48 h at 35°C in the presence of 5% CO2. CB-839 Before sample preparation, the isolates were re-grown for 48 h at 35°C in the presence of 5% CO2. Sample preparation was performed according to the company guidelines (Bruker Daltonics,

Bremen, Germany). Briefly, 30 colonies were suspended in 300 μl of water (MilliQ, Millipore, Billerica, MA, U.S.) and mixed carefully. Next, 900 μl of absolute ethanol (Fisher Scientific, Loughborough, UK) was added and the suspension was mixed. Subsequently, the suspension was incubated for 90 min to inactivate all of the bacteria. After this inactivation step, the suspension samples were centrifuged aminophylline for 10 min at 10, 000 g. The supernatant was removed. To remove the PD-0332991 cell line remaining ethanol residue, the spinning step was repeated, and the remaining supernatant was removed. Subsequently, 50 μl of 70% formic acid was added to the pellet, and the pellet was mixed. Next, 50 μl of pure acetonitrile (LC-MS grade, Fluka/Aldrich, Stenheim,

Germany) was added, and the suspension was mixed carefully. The particulate matter that could not be dissolved was spun down by centrifugation for 2 min at 10, 000 g. Finally, four spots were created, using 0.5 μl of the supernatant per spot, onto a MALDI-TOF target plate (MTP 384 target polished steel #209519, Bruker Daltonics) and air dried. Subsequently, the spots were overlaid with 0.5 μl of α-cyano-4-hydroxycinnamic acid (HCCA, Bruker Daltonics) and a 10 mg/ml acetonitrile/water solution (1:1) with 2.5% trifluoroacetic acid (TFA) (Fluka/Aldrich, Stenheim, Germany) and dried at room temperature. Mass spectra acquisition All of the mass spectra were automatically acquired on a Bruker Autoflex III smartbeam instrument (Bruker Daltonics GmbH, Bremen, Germany) in linear mode using the following parameters: 40% laser intensity, positive polarity, 350 ns PIE delay, 20 kV Z-VAD-FMK research buy source voltage 1, 18.7 kV source voltage 2, 8 kV lens voltage, 1.522 kV linear detector voltage, and 800 Da detector gating.