Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry in Clinical Microbiology: What Are the Current Issues?

Abstract

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized the identification of microbial species in clinical microbiology laboratories. MALDI-TOF-MS has swiftly become the new gold-standard method owing to its key advantages of simplicity and robustness. However, as with all new methods, adoption of the MALDI-TOF MS approach is still not widespread. Optimal sample preparation has not yet been achieved for several applications, and there are continuing discussions on the need for improved database quality and the inclusion of additional microbial species. New applications such as in the field of antimicrobial susceptibility testing have been proposed but not yet translated to the level of ease and reproducibility that one should expect in routine diagnostic systems. Finally, during routine identification testing, unexpected results are regularly obtained, and the best methods for transmitting these results into clinical care are still evolving. We here discuss the success of MALDI-TOF MS in clinical microbiology and highlight fields of application that are still amenable to improvement.

Keywords: Antibiotic susceptibility testing; Future perspectives; MALDI-TOF MS; Mass Spectrometry; Routine clinical microbiology; Sample preparation; Taxonomy.

Fig. 1. Schematic summary of commonly applied sample preparation procedures for particular types of samples in matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based microbial identification. See the text for details.

Abbreviation: BSL, biological safety level.