Mycobacterium abscessus Complex Identification with Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

We determined that the Vitek MS Plus matrix-assisted laser desorption ionization–time of flight mass spectrometry using re-search-use-only (RUO) v.4.12 and in vitro-diagnostic (IVD) v.3.0 databases accurately identified 41 Mycobacterium abscessus subsp. abscessus and 13 M. abscessus subsp. massiliense isolates identified by whole-genome sequencing to the species but not the subspecies level, from Middlebrook 7H11 and Burkholderia cepacia selective agars. Peak analysis revealed three peaks poten-tially able to differentiate between subspecies. Nontuberculous mycobacteria (NTM) are emerging patho-gens with increasing prevalence in clinical settings in the in-dustrialized world (1). Mycobacterium abscessus is emerging as a significant respiratory pathogen accounting for a large proportion of NTM disease in cystic fibrosis (CF) patients (2–6). They also cause a variety of infections in non-CF patients, such as chronic pulmonary, skin and soft tissue, and postsurgical infections (7). Recent evidence (8, 9) supported by whole-genome sequenc-ing (WGS) data (2) suggest that the M. abscessus complex com-prises three subspeciesM. abscessus subsp. abscessus (sensu stricto), M. abscessus subsp. massiliense, and M. abscessus subsp. bolleti