Benefits and Limitations of MALDI-TOF Mass Spectrometry for the Identification of Microorganisms

Abstract

Matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) is replacing traditional methods for identifying microorganisms in the clinical laboratory. This relatively simple technique overcomes many of the challenges of identifying bacteria and fungi. As the technology has evolved, the expansion of the databases containing spectra of known organisms has allowed for the identification of species with similar phenotypic, genotypic, and biochemical properties that was not previously possible. This has resulted in improvements in clinical care including improving the diagnosis of infections caused by relatively rare species and decreasing the time to diagnosis. In many cases, this leads to a reduction in the time to appropriate therapy and even a decrease in the length of hospital stays. However, it is not without its limitations. Inherent similarities between organisms and a limited number of spectra in the database can lead to poor discrimination between species, as well as misidentifications. These errors occur with relatively low frequency and can typically be overcome with supplemental testing. The adoption of MALDITOF MS in the clinical microbiology laboratory is revolutionizing infectious disease diagnosis and clinical care.