FT-IR

 

Under the FT-IR tab on the MALDI-UP website, we compile tools and resources for microbiological applications of Fourier transform infrared spectroscopy.

FT-IR has been used for the characterization of microorganisms for > 25 years. The applications include identifications at the species level and determination of sero- and biotypes or pathogenicity factors. The direct comparison of spectra also often enables a rapid analysis of contamination routes.

The measuring principle:
FT-IR maps the entirety of the biochemical composition of microorganisms. Molecules are stimulated to move (vibrate, rotate) by infrared rays (heat radiation). Certain bonds in chemical functional groups absorb radiation energy. The absorption of molecular bonds in biomolecules such as fats, proteins or ribonucleic acids at different wavelengths of infrared light leads to a characteristic overall spectrum that reflects the current metabolic status or phenotype of the cells. By standardizing the cultivation conditions, reproducible spectra can be generated from the isolates, which - like a fingerprint - represent a typical pattern for the respective isolate. Using artificial neural networks, the technique shows a very good resolution in taxonomic areas far below the species level.

 

Validation

Using the principles of the Guidelines for validating species identifications using MALDI-TOF-MS (BVL, 28 Oct 2022)

 

Serogroups of Listeria monocytogenes

 

Serogroups of Salmonella

 

Literature

FT-IR related publications can be found in our specific literature section