Just Do It with a MALDI! Are Microbiologists Mutating into Chemists? (15 minutes presentation and open exchanges)

The challenges for food microbiology are as varied and numerous as the requirements for bacterial identification methods. One requirement, among many, is that food spoilers, foodborne pathogens, starter cultures, and probiotics must be accurately identified. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has revolutionized microbial identification, and is increasingly recognized as an established tool and alternative for identification of isolates in the complex food chain.

MALDI-TOF MS identification is based on the acquisition of a protein fingerprint of the microorganism. In contrast to conventional biochemical or molecular methods, same workflows can be used whatever the microorganisms. This facilitates the implementation into routine analysis. The measured MS profiles are compared to a database for identification. A critical factor, influencing the accuracy of the identification, is the quality of the database. Results are available within minutes. After a short summary of the principle and workflow, the use of this high-throughput technology in food microbiology will be illustrated with recent applications.

At the end of the 20^th century, microbiologists underwent an initial transfer by becoming molecular biologists and producing genotypes. Are they now moving toward becoming chemists, by just doing it with a MALDI? It looks like this emerging technology improves workflow during a typical day in routine testing labs.