Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: a Fundamental Shift in the Routine Practice of Clinical Microbiology

Abstract

SUMMARY Within the past decade, clinical microbiology laboratories experienced revolutionary changes in the way in which microorganisms are identified, moving away from slow, traditional microbial identification algorithms toward rapid molecular methods and mass spectrometry (MS). Historically, MS was clinically utilized as a high-complexity method adapted for protein-centered analysis of samples in chemistry and hematology laboratories. Today, matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) MS is adapted for use in microbiology laboratories, where it serves as a paradigm-shifting, rapid, and robust method for accurate microbial identification. Multiple instrument platforms, marketed by well-established manufacturers, are beginning to displace automated phenotypic identification instruments and in some cases genetic sequence-based identification practices. This review summarizes the current position of MALDI-TOF MS in clinical research and in diagnostic clinical microbiology laboratories and serves as a primer to examine the “nuts and bolts” of MALDI-TOF MS, highlighting research associated with sample preparation, spectral analysis, and accuracy. Currently available MALDI-TOF MS hardware and software platforms that support the use of MALDI-TOF with direct and precultured specimens and integration of the technology into the laboratory workflow are also discussed. Finally, this review closes with a prospective view of the future of MALDI-TOF MS in the clinical microbiology laboratory to accelerate diagnosis and microbial identification to improve patient care.

Microbiological and parasitological survey of zoonotic agents in apparently healthy feral pigeons

“…In the present work, not all isolates of yeasts evidenced by biochemical test were confirmed and/or detected by MALDI TOF MS. Despite the specificity of the tool, Clark et al (2013) evidenced that data-bases of MALDI TOF MS are not developed for several yeast species and this could justify the lower number of isolates identified. However, the detection of several zoonotic yeasts from pigeons located in urban areas can provide useful preliminary information for epidemiological and risk assessment studies.…”

Mycobacterial Typing Systems: The Good, the Bad and the Unattainable

“…The exploitation of differences in surface proteins expressed by mycobacteria using mass spectrometry and Raman spectroscopy has showed some promise [25,26]. There needs to be further work to assess the utility of mass spectrometry as a typing tool and whether reported issues with reproducibility and lack of standardization can be overcome [27]. The limitations mentioned have stymied phenotypic typing.…”

Identification of Coagulase-Negative Staphylococci by the Bruker MALDI-TOF Biotyper Compared To the Vitek 2 and MIS Gas Liquid Chromatography

“…These automated identification and susceptibility systems are hampered by the organism's ability to express specific metabolic activity and morphological features. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) has revolutionized clinical microbiology laboratories making rapid and accurate identification possible [13]. A study performed by Wragg and associates compared the identification of seventy six bacterial isolates by the Biolog GEN III MicroStation semiautomated bacterial identification system and the VITEK MS matrix-assisted laser desorption ionization-time of flight mass spectrometry [14].…”