Evaluation of the mycobacteria MBT kit for identification of nontuberculous mycobacteria by MALDI-TOF Biotyper (Bruker)

Abstract

Identification of mycobacteria is crucial for clinical management of patients. The new MBT Mycobacteria kit from the Easy MycoEx protocol (Bruker) is used for the identification of mycobacteria by MALDI Biotyper. The Easy MycoEx protocol was compared to the MycoEx protocol (1) for identification of various mycobacterial isolates collected from samples in 2021, (2) for prospective identification on primary culture during 2 periods. For 44 isolates in MGIT broth, identification rates were high and similar for both protocols (98% vs 95% at cut-off 1.6 and 91% vs 82% at cut-off 1.8). For 42 mycobacteria on Coletsos agar, identification rates were 88% versus 90% at cut-off 1.6 and 76% for both protocols at cut-off 1.8. For slow-growing mycobacteria in MGIT, reproducibility of deposit results was superior with Easy MycoEx. No difference of score was observed between 2 protocols performed on primary culture. Clinical laboratories can easily implement the Easy MycoEx protocol.

Keywords: Identification; MALDI-TOF MS; MBT Mycobacteria kit; Nontuberculous mycobacteria.