Mass spectrometry applications in infectious disease and pathogens identification

Background Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a powerful tool in the clinical microbiology laboratory enabling accurate identification of bacteria, fungi, and mycobacteria. First adopted in European microbiology laboratories, its ease of use, accuracy, rapid turnaround times, and low cost have led to its widespread adoption in microbiology laboratories worldwide. In contrast, polymerase chain reaction electrospray ionization-mass spectrometry (PCR-ESI-MS) is an emerging technology for clinical microbiology with the potential for direct-from-sample testing and actionable results in a few hours. Content This first half of this chapter briefly discusses the history of MALDI-TOF-MS leading to its commercialization and adoption in clinical microbiology laboratories. Identification of aerobic and anaerobic organisms as well as mycobacteria and fungi is discussed. Additional applications, such as direct identification from blood and urine cultures as well as antimicrobial susceptibility testing are also reviewed. Additionally, implementation of MALDI-TOF-MS into routine laboratory workflows is addressed. The second half of this chapter discusses PCR-ESI-MS and its potential applications in the clinical microbiology laboratory in its current state.