MALDI-TOF MS: Its Application in the Clinical Laboratory and a Paradigm Shift in Clinical Microbiology

ABSTRACT

In the past decade, clinical microbiology underwent revolutionary changes in methods used to identify microorganisms, a transition from slow and traditional microbial identification algorithms to rapid molecular methods and mass spectrometry (MS). Earlier, MS was clinically used as a highly complex method that was adapted for protein-centered analysis of samples in chemistry laboratories. Recently, a paradigm-shift happened when matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS was implemented to be used in microbiology laboratories for rapid and robust methods for accurate microbial identification. Two instrument platforms, marketed by well-established manufacturers, are beginning to displace automated phenotypic identification instruments and in some cases even genetic sequence-based identification practices. This review summarizes the current role of MALDI-TOF MS in clinical research, in diagnostic clinical microbiology laboratories, and serves as an introduction to MALDI-TOF MS, highlighting research associated with sample preparation, algorithms, interpretations, and limitations. Currently available MALDI-TOF MS instruments as well as software platforms that support the use of MALDI-TOF with direct specimens have been discussed in this review. Finally, clinical laboratories are consistently striving to extend the potential of these new methods, often in partnership with developmental scientists, resulting in novel technologies, such as MALDI-TOF MS, which could shape and define the diagnostic landscape for years to come.