Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS) for Investigation of Mycobacterium tuberculosis Complex Outbreaks: a Type Dream?

The positive impact that matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has had on clinical microbiology over the past decade has been well established (1). However, unfortunately, the reliable identification to the species level of Mycobacterium tuberculosis complex (MTC) isolates has not to date been achievable by MALDI-TOF MS. Nevertheless, some researchers have shown that MALDI-TOF MS coupled with in silico analysis has been useful as a typing tool for other mycobacterial groupings that were not previously possible, including Mycobacterium kansasii (2), differentiating Mycobacterium chimaera from Mycobacterium intracellulare (3), and distinguishing Mycobacterium avium subsp. paratuberculosis from other M. avium subspecies (4). In this study, we set out to examine whether MALDI-TOF MS could be used as a typing tool for outbreak investigations.