Matrix-assisted laser desorption ionization-time of flight mass spectrometry for microbial identification in clinical microbiology

After several decades of limited progress, the practice of clinical microbiology is beginning to evolve on a more rapid scale. The introduction of immunological methods in the 1970s was followed by the introduction of automated biochemistry-based identification systems, automated antimicrobial susceptibility testing systems, and automated blood culture instruments in the 1980s and 1990s, and thereafter by the gradual adoption of nucleic acid amplification tests over the past 25 years. Today, there is an accelerated pace of introduction of novel technologies into clinical microbiology laboratories (1). Easy-to-use panel-based molecular testing and automated workflow are in the process of being adopted. Workflow optimization is being facilitated by the introduction of automated equipment, with rapid identification of microbial pathogens being a key component (2). A revolutionary new entry, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), has been introduced into clinical microbiology laboratories over the past 5 years as a tool for microbial identification (3-5). The quality of MALDI-TOF MS with respect to bacterial identification already seems to surpass that of more classical growth-based technologies (6). The reason for the rapid adoption of this technology is that it is simple, high speed, cost-effective, and at least as good as, if not better than, conventional identification strategies. Sometimes the combination of classical technologies such as Gram staining with MS is advocated, but most people agree that MS will be able to function as a stand-alone technology for bacterial identification (7).