Mass spectrometry in the clinical microbiology laboratory

Infectious diseases are still a cause of high mortality and morbidity rates. Current microbiological diagnostic methods are based on culture and phenotypic identification of isolated microorganisms, which can be obtained in about 24-48 h. Given that the microbiological identification is of major importance for patient management, new diagnostic methods are needed in order to detect and identify microorganisms in a timely and accurate manner. Over the last few years, several molecular techniques based on the amplification of microbial nucleic acids have been developed with the aim of reducing the time needed for the identification of the microorganisms involved in different infectious processes. On the other hand, mass spectrometry has emerged as a rapid and consistent alternative to conventional methods for microorganism identification. This review describes the most widely used mass spectrometry technologies - matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization time-of-flight (ESI-TOF) - , both for protein and nucleic acid analysis, as well as the commercial platforms available. Related publications of most interest in clinical microbiology are also reviewed.