Evaluation of the compatibility of Phoenix 100 and Microflex LT MALDI-TOF MS systems in the identification of routinely isolated microorganisms in the clinic microbiology laboratory

Background: Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS) is a quick, reliable, and efficient system for identifying microorganisms. Many centers that use the Phoenix 100 system today may adopt aMALDI-TOF MS system in the future. Our laboratory recently undertook this pivot. The present study evaluates the reproducibility of species identifications made by the Phoenix 100 and MALDI-TOF MS systems, during a period of transitioning laboratory instrumentation. Methods: Eight hundred and twelve microbial isolates, from aerobic cultures of different clinical samples, were identified simultaneously with Phoenix 100 (Becton Dick-inson, Sparks, MD, USA) and a Microflex LT MALDI-TOF MS (Bruker Daltonics, Bremen, Germany) devices. Results: Both systems made identical species assignments for 98.9%, 92.1%, 95.1%, and 93.1% of Gram-negative isolates, catalase-positive Gram-positive cocci isolates, cat-alase-negative Gram-positive cocci isolates, and Candida isolates, respectively. Conclusions: Identifications made by two instruments commonly used in microbiology laboratories, the Phoenix 100 and the Microflex LT MALDI-TOF MS, are highly consistent.