VITEK 2 Compact and VITEK MS: Introduction, Differences and Keynotes

Introduction

The VITEK 2 compact system is an automated microbiology bacteria and yeasts identification and antimicrobial susceptibility system which uses biochemicals for microbial identification whereas, VITEK MS performs the same function by covering a large number of microbes in a short time period at a low cost and works on the principle of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS).

Differences

The differences between them are as follows-

Features	VITEK 2 Compact	VITEK MS
Working Principle	A fluorogenic methodology for microbial identification and a turbidimetric method for susceptibility testing	MALDI-TOF Mass Spectrometry
Technique	Older	Newer
Time taken for processing	Slower	Faster
Application	For bacteria and yeasts	For bacteria and fungi (yeasts and molds)
Testing cost	Comparatively expensive	Chief
Specificity	Comparatively medium	Comparatively high
Criteria for Acceptance of Identification	Comparatively medium	Comparatively high
Disagreeing results in coagulase-negative staphylococci (CoNS) identification	1. Staphylococcus lugdunensis (93%) 2. Staphylococcus epidermis (99%)	1. Staphylococcus aureus (99.9%) 2. Staphylococcus hominis ssp. hominis (99.9%)

Keynotes

1. The highly mucoid strain of the organism may not provide acceptable results in VITEK 2 Compact and thus alternative methods should be applied for these organisms.
2. Colonies grown on EMB plates cannot be processed in VITEK 2 Compact because of the carry-over of the dye present in the medium.
3. Technological advances made by the VITEK MS make it possible to report culture results faster, which has not only the potential to improve patient care, but also shorten the length of stay and reduce health care costs.
4. API20E/NE,VITEK 2 Compact (VTC), VITEK 2 60 (VT60) and the VITEK MS (VMS) all are product of bioMérieux.
5. API20E/NE, VITEK 2 Compact (VTC), and VITEK 2 60 (VT60) use biochemical for identification while VITEK MS (VMS) uses MALDI-TOF Mass Spectrometry.
6. MALDI-TOF mass spectrometry (MS) is widely used technique for the rapid and accurate identification of microbes like bacteria, mycobacteria and certain fungal pathogens in the clinical microbiology laboratory.

Bibliography

• https://www.researchgate.net/publication/275582707_Agreement_and_Cost_Comparison_of_VITEK2_Compact_VITEK2_60_VITEK_MS_Systems_and_API20ENE_using_Clinical_Gram-negative_Bacilli_Isolates_from_Jamaica
• https://medicallabnotes.com/tag/test-requirements-for-vitek/
• https://dohs.gov.np/wp-content/uploads/2021/07/DoHS-Annual-Report-FY-2076-77-for-website.pdf
• https://www.gundersenhealth.org/app/files/public/4608fc82-436a-481a-b59f-da2bc1fdb31c/Lab-Policies-Vitek-2-Compact—Identification-and-Susceptibility-Testing-Lab-1512.pdf
• https://www.infectiologyjournal.com/articles/benefits-and-limitations-of-malditof-mass-spectrometry-for-the-identification-of-microorganisms.html