VITEK MS Prime: Introduction, Principle, Components, Procedure, Result -Interpretation, Application, and Keynotes

Introduction

The VITEK MS PRIME is a benchtop, high-throughput automated identification system that works on the principle of Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) mass spectrometry. It is applicable to enhance laboratory workflow for the rapid identification of microbes like bacteria, yeasts, molds, and mycobacteria. 

Principle

The system operates on the MALDI-TOF principle. Ionization: A 337 nm nitrogen laser “zaps” a sample on a target slide. Desorption: The energy from the laser, absorbed by a matrix (CHCA), causes the sample to vaporize and ionize. Time of Flight (TOF): These ions are accelerated through a vacuum flight tube (1.2 m length). Fingerprinting: Smaller ions travel faster than larger ones, and the time it takes them to reach the detector creates a unique protein fingerprint (mass-to-charge ratio) of the organism. 

Components of VITEK MS Prime

• Instrument: A benchtop mass spectrometer with an on-board Personal Computer, adjustable monitor, and integrated keyboard.
• Target Slides: Disposable, uniquely barcoded VITEK MS-DS slides with 48 sample spots each.
• Reagents:
  • VITEK MS-CHCA: A ready-to-use matrix solution.
  • VITEK MS-FA: Formic acid used for yeast and fungi pretreatment.
  • SMARTCALIBRANT: Liquid format for standardized Escherichia coli calibration.
• VITEK PICKME Pen: A tool for standardized colony picking and thin smearing on target slides.
• Software: Uses the Advanced Spectra Classifier (ASC) algorithm and MYLA middleware for data integration and results reporting.

Procedure

1. Sample Preparation: Smear a colony onto a spot on the target slide using a loop or the PICKME pen.
2. Matrix Addition: Add 1 µL of CHCA matrix to the spot and allow it to dry.
3. Loading: Load slides into the instrument using a continuous “Load and Go” system (up to 16 slides/768 samples).
4. Acquisition: The laser automatically fires at the spots, and then ions are detected and analyzed.
5. Prioritization: A one-click “urgent slide” feature is available for critical samples.

Result Interpretation

• Advanced Spectra Classifier (ASC): Instead of simple pattern matching, the algorithm considers peak weights and presence or absence across 1,300 bins.
• Confidence Levels: Results display in a probability percentage; a confidence level of>99% indicates unambiguous identification.
• Display: Results are in color-codes (e.g., green for high confidence) for easy review.
• Species Discrimination: The system gives single-choice results that effectively differentiate between closely related species.

Application of VITEK MS

• Clinical Microbiology: Rapid identification of microorganisms such as bacteria, yeasts, and fastidious organisms (Mycobacteria, Nocardia).
• Pharmaceutical Quality Control: Species-level identification for environmental monitoring and sterility testing (compliant with 21 CFR Part 11).
• Antimicrobial Stewardship (AMS): Quick identification (within minutes) allows for earlier targeted antibiotic therapy.
• Food Safety: It helps to identify pathogens in food and beverage production environments.

Keynotes

• Load and Go: Continuous slide loading allows for zero-wait workflow integration.
• Traceability: End-to-end tracking from sample to result via barcodes.
• Maintenance: Features automated fine-tuning of ion optics to maximize system uptime.
• Integration: Excellent links with VITEK 2 for automated ID (Identification)/AST (Antimicrobial Susceptibility Testing) reporting.

Further Readings

1. https://www.biomerieux.com/corp/en/our-offer/clinical-products/vitek-ms-prime.html
2. https://www.biomerieux.com/us/en/our-offer/clinical-products/vitek-ms.html
3. https://nvri.gov.ng/index.php/single/VITEK-MS-%28mass-spectrometry
4. https://www.biomerieux.com/corp/en/our-offer/industry-products/vitek-ms-prime-mass-spectrometry-system.html
5. https://www.accessdata.fda.gov/cdrh_docs/reviews/K162950.pdf
6. https://www.biomerieux.com/content/dam/biomerieux-com/03—-our-offer/clinical/in-hospital–in-lab/specialty/veterinary-diagnostics/documents/BROCHURE%20VITEK%20MS%20PRIME%20VET.pdf.coredownload.pdf
7. https://www.biomerieux.com/us/en/our-offer/clinical-products/vitek-ms-prime.html
8. https://nvri.gov.ng/index.php/single/VITEK-MS-%28mass-spectrometry
9. https://go.biomerieux.com/ms-prime
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC11124449
11. https://www.biomerieux.com/nl/en/our-offer/clinical-products/vitek-ms.html
12. https://www.mdpi.com/2076-2607/12/5/964