Growth Media on Performance of Mycobacteria Identification Using Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Identification of mycobacterial infections for both Mycobacterium tuberculosis and non-tuberculosis mycobacteria is important for effective patient care. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a promising tool that is used in many clinical laboratories for the identification of bacteria and yeast. This study evaluates the impact of growth media on the performance of the MALDI Biotyper® MBT smart MS for mycobacteria identification. Increased rates of identification, particularly in non-rapid growers and pigment producers, and higher confidence scores were generated in mycobacteria isolated from solid agar, rather than liquid broth. Testing each isolate in triplicate can increase yield of detection. Using the Bruker MBT Mycobacteria Kit to process our samples for testing on the Bruker MALDI Biotyper® instrument generated precise and accurate mycobacteria identification. These findings emphasize the importance of optimizing mycobacterial specimen processing workflows to include appropriate culture media, which can enhance mycobacterial identification and improve diagnostic accuracy.