# Decoding anaerobes: a comprehensive evaluation of MALDI-TOF Sirius and VITEK MS PRIME in clinical settings

## TL;DR

This study compares two MALDI-TOF mass spectrometry platforms for identifying anaerobic bacteria, showing they offer fast, accurate, and cost-effective results for clinical use.

## Contribution

A direct comparison of Bruker SIRIUS and VITEK MS PRIME platforms for anaerobe identification using FDA-approved clinical strains.

## Key findings

- MALDI-TOF MS achieved over 97% genus-level identification accuracy for anaerobic bacteria.
- Both platforms showed 100% precision but varied in overall performance agreement at 73.3%.
- The study highlights practical insights for selecting MALDI-TOF systems in clinical labs.

## Abstract

The timely identification of anaerobic bacteria at the genus and species
levels is critical for managing infections and guiding antimicrobial
therapy. Matrix-assisted laser desorption-ionization time-of-flight
(MALDI-TOF) mass spectrometry (MS) has emerged as a powerful tool for the
identification of anaerobic bacteria, overcoming challenges associated with
their special culture requirements and low growth rates. This technique has
proven to be both reliable and efficient, providing accurate identification
with minimal bacterial biomass. The application of MALDI-TOF MS in clinical
settings has significantly improved the identification of anaerobic
bacteria, facilitating appropriate treatment decisions and enhancing patient
outcomes with minor costs. This study evaluates the performance of two
MALDI-TOF mass spectrometry platforms: SIRIUS (Bruker Daltonics) and VITEK
MS PRIME (bioMérieux), and their latest libraries, using a panel of
60 clinically relevant anaerobic strains validated in IVD databases and
approved by the Food and Drug Administration. Beyond identification
accuracy, we highlight the role of rapid confirmation of anaerobic pathogens
in improving clinical outcomes. Results are compared against the existing
literature, including performance evaluations of our group, to underscore
the advancements in MALDI-TOF technology. MALDI-TOF MS has demonstrated high
accuracy in identifying anaerobic bacteria, with a genus identification
success rate of over 97%, combined with a precision value of 100% and an
overall performance agreement of 73.3%, with some minor discrepancies, so
the choice of one or the other platform will depend on the needs of each
particular laboratory.

Rapid and accurate identification of anaerobic bacteria is essential for
guiding antimicrobial therapy and improving patient outcomes, yet it
remains challenging due to the organisms’ fastidious nature.
Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF)
mass spectrometry has transformed clinical microbiology by enabling
high-throughput, cost-effective, and reliable identification of
anaerobes. This study provides a head-to-head comparison of two widely
used MALDI-TOF platforms—Bruker SIRIUS and VITEK MS
PRIME—using a panel of clinically relevant anaerobic strains. By
assessing their diagnostic accuracy, reproducibility, and database
performance, our results offer practical insights for laboratories
selecting a MALDI-TOF system. The findings have direct implications for
improving diagnostic workflows, reducing time-to-result, and enhancing
antimicrobial stewardship in clinical settings. Furthermore, this work
contributes to the development of national resources and tools that
support MALDI-TOF-based diagnostics in low- and middle-income
settings.