MALDI-TOF mass spectrometry applied to microbiology and virology

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is increasingly utilized as a rapid technique to identify microorganisms by their molecular fingerprint and/or by biomarker detection. Although the massive number of entries in the available Maldi Biotyper database Bruker Daltonics, the absence of reference spectra of some species as dermatophyte fungi or bacteria such as spirochaetes, does not allow their identification. Moreover, very few reports are available about its application in parasitology and virology. In this study, in a first approach, the commercial database of the spectrometer used in our laboratory was supplemented with additional spectra. Initially, the profiles of several Brachyspira, Borrelia, Leptospira and dermatophyte species were included without any intervention on setting; subsequently, the versatility of the system allowed us also to supplement the database with the spectra of the parasite Trichomonas vaginalis and with that of respiratory viruses infected cells, extensively modifying the parameters commonly set for the routine identification of bacteria and fungi. In a second approach, when needed, the identification of other parasites, such as Entamoeba histolytica and E. dispar, and of other viruses (poliovirus) at serotype level was achieved by protein biomarker detection.