Nocardia species are the most commonly isolated aerobic actinomycetes from human clinical specimens. Our objective was to assess the identification of clinically relevant actinomycetes using the Bruker Biotyper MALDI-TOF system, including comparison of extraction methods, Biotyper library versions, score cutoffs, and media. Banked Streptomyces (n = 10), Tsukamurella (n = 2), and Nocardia isolates (n = 60) were cultured and extracted using three methods: mycobacterial extraction, ethanol formic acid extraction, or direct on-target extraction. Following MALDI-TOF analysis, spectra were analyzed using versions 5 and 6 of the BDAL Biotyper library. Optimal species-level identifications for Nocardia were achieved using BDAL v6 at a score cutoff of ≥1.8 after direct extraction (49/60, 82%). Overall, the Biotyper platform with BDAL v6 accurately identified 12/16 species of Nocardia, demonstrating the utility of MALDI-TOF for identification of clinically relevant actinomycetes without the need for supplementation of the database.
|Number of pages||6|
|Journal||Diagnostic Microbiology and Infectious Disease|
|State||Published - Oct 2017|
- Bruker Biotyper
- MALDI-TOF MS