Performance comparison of VITEK MS PRIME with VITEK MS in clinical hospital laboratory setting

MALDI-TOF mass spectrometry has been instrumental in rapid organism identification from clinical microbiology cultures. bioMérieux’s latest MALDI-TOF mass spectrometer for in vitro diagnostic laboratory use is the VITEK MS PRIME (MS PRIME). This instrument features a new internal multi-slide holder and streamlined sample acquisition. In this study, we performed a direct comparison between the MS PRIME and the VITEK MS for identification accuracy and time to result, to evaluate performance in a clinical laboratory setting. Two hundred fifty micro-organism isolates recovered from the University of Maryland Medical Center (UMMC) routine patient cultures were evaluated. Diagnostic accuracy for the MS PRIME was determined using the VITEK MS identification as the reference method. Organisms were considered correctly identified by the MS PRIME if an identification scored >99.0% confidence on at least two spots, and matched the VITEK MS identification. Slide loading and sample spot acquisition times were measured to compare functional time from slide preparation to receipt of final identification result for diagnostic reporting. The MS PRIME demonstrated high identification accuracy with 98.0% accuracy for all microbial isolates tested, except five failures from anaerobic bacteria (245/250). Average time to first sample acquisition from slide loading was 4 min 13 s for MS PRIME and 10 min 28 s for VITEK MS. Average spot acquisition time was significantly faster for MS PRIME (14 s, n = 100) compared to VITEK MS (25 s, n = 100). The MS PRIME demonstrates significantly faster time to results without significant loss in accuracy of microbial identification.