Aims: To evaluate the performance of two matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry platforms to identify molds isolated from clinical specimens. Methods: Fifty mold isolates were analyzed on Bruker Biotyper® and Vitek® MS platforms. Two Bruker Biotyper extraction protocols were assessed alongside the US FDA-approved extraction protocol for Vitek MS. Results: The Bruker Biotyper modified NIH-developed extraction protocol correctly identified more isolates than Bruker's protocol (56 vs 33%). For species in the manufacturers' databases, Vitek MS correctly identified 85% of isolates, with 8% misidentifications. The Bruker Biotyper identified 64%, with no misidentifications. For isolates not in the databases, the Bruker Biotyper did not misidentify any, and Vitek MS misidentified 36%. Conclusion: Both the Vitek MS and Bruker Biotyper accurately identified the fungal isolates, however Vitek MS was more likely to misidentify isolates than the Bruker Biotyper.
Keywords: clinical laboratory techniques; diagnostic techniques and procedures; fungi; hospital laboratories; mass spectrometry; matrix-assisted laser desorption-ionization; microbiology.
There are two different mass spectrometry systems that can be used in the hospital laboratory to find out what kind of mold is growing from a patient sample: the Vitek® MS and Bruker Biotyper® systems. This study compared how well they work for mold identification and also looked at two different ways to prepare the mold for testing. The Vitek MS system identified more molds, but also made more mistakes when identifying them. The Bruker Biotyper identified fewer molds but did not make any mistakes on the identification. The Vitek MS system sometimes gets the type of mold wrong, so more tests may be needed to be sure of the result. The Bruker Biotyper is more accurate because it got all of the molds correct, but it could not identify as many.