Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Fails To Identify Nontuberculous Mycobacteria from Primary Cultures of Respiratory Samples

We have assessed matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification (Bruker) of nontuberculous mycobacteria from newly positive liquid cultures of respiratory samples. Twelve (22%) of 54 isolates were identified directly from liquid medium. After subculture and with manual laser operation, this rose to 49/54 isolates (91%). MALDI-TOF MS is less promising than previously suggested.