Vitek ms device

Blood (2 × 20 mL) was obtained from the peripheral veins of patients before treatment with antibiotics was started. It is unknown whether patients had received antibiotics prior to hospitalization. Blood (10 mL) was added to each of two culture flasks containing resins for antibiotic neutralization. Blood cultures (BACTEC™ Plus Aerobic/F and BACTEC™ Plus Anaerobic/F culture vials; Becton-Dickinson, Franklin Lakes, NJ, USA) were obtained in accordance with current blood culture guidelines [29 (link)] and incubated in an automated blood culture system (BD BACTEC FX; Becton-Dickinson) for 5 days at 37 °C. Positive blood cultures were Gram-stained, streaked onto Columbia sheep blood agar, chocolate agar, MacConkey lactose agar, and Schaedler agar (Becton-Dickinson) for overnight incubation at 37 °C, and species identification was then carried out using matrix-assisted laser desorption ionization time-of-flight mass spectrometry on a VITEK^®MS device (bioMérieux, Marcy l’Étoile, France).

Mass spectrometry based on Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) was performed in a VITEK^® MS device (bioMérieux) (wavelength: 337.1 nm, beam divergence: 3.5 × 3 mrad; rate repetition and pulse duration: 3 ns/60 Hz; Maximum output: 150 μJ/pulse). Data were processed by Acquisition Software. Experiments were performed in biological duplicate, using two independent OMV extracts.