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How does MALDI-TOF mass spectrometry work for bacterial identification?

How does MALDI-TOF mass spectrometry work for bacterial identification?

MALDI-TOF measures the mass of molecules from a sample that has been embedded in a matrix by using a laser to ablate and desorb the molecules with minimal fragmentation.

Can MALDI-TOF mass spectrometry reasonably type bacteria?

MALDI-TOF MS has also been successfully used to discriminate bacterial groups by the analysis of mass spectra of specific bacterial extracts. For instance, fatty acid profiles obtained after lipid extraction have been successfully used for bacterial identification [59].

What is 2d gel electrophoresis used for?

Two-dimensional gel electrophoresis (2DGel) is a successful method used for the detection and analysis of proteins. It has been designed as a combination of the 2DGel, IEF and SDS-PAGE methods, and is used in the analysis of complex protein mixtures.

What is MALDI-TOF bacterial identification?

MALDI-TOF MS is an innovative tool that is easy to use, rapid, accurate, and cost-effective, and that has revolutionized bacterial identification in clinical microbiology laboratories. MALDI-TOF MS allows the identification of microorganisms at the species level by analysis of total protein (Box 1) [1].

What is the basic principle of 2d gel electrophoresis?

The principle applied was very simple: proteins were resolved on a gel using isoelectric focusing (IEF), which separates proteins in the first dimension according to their isoelectric point, followed by electrophoresis in a second dimension in the presence of sodium dodecyl sulfate (SDS), which separates proteins …

Why is MALDI-TOF better?

In many cases it has shown resolution and reproducibility which is better than gel-based protein or DNA fingerprinting techniques (van Baar, 2000; Fenselau and Demirev, 2001; Lay, 2001). Numerous studies have shown that MALDI-TOF MS is a rapid, reliable and cost-effective technique for identification of bacteria.

What are the advantages of MALDI-TOF?

A major advantage of MALDI-TOF is its rapid turnaround time (<10 mins) and an overall 95% accuracy at the species level, enabling a faster, correct treatment for the patients (). Another benefit of the MALDI-TOF in microbiological diagnostic is its low-cost in supplies and technician processing time ().

How are microbes identified by MALDI TOF MS?

Identification of microbes by MALDI-TOF MS is done by either comparing the PMF of unknown organism with the PMFs contained in the database, or by matching the masses of biomarkers of unknown organism with the proteome database.

Which is the third generation of gel electrophoresis?

Pulsed-field gel electrophoresis (PFGE) is considered the “third-generation molecular approach” for bacteria typing ( Goering, 2010 ); the first- and second-generations being plasmid analysis and genome enzyme restriction.

How is the MALDI principle used in mass spectrometry?

MALDI – Principle and Methodology. The solvents penetrate the cell wall of microorganisms and extract out the intracellular proteins. When the solvent evaporates, ‘co-crystallization’ of protein molecules and other cellular compounds entrapped within the matrix solution takes place ( Horneffer et al., 2001 ).

Are there alternatives to pulsed field electrophoresis ( PFGE )?

PCR-based typing such as rep-PCR, ERIC-PCR and MLVA can be alternatives for PFGE. Some laboratories are transitioning towards whole genome sequencing-based typing. PFGE remains important for small hospitals and laboratories with limited resources.