New mass spectrometry tool accurately identifies bacteria

Scientists identify bacterial species by analyzing their proteins using mass spectrometry, or MS. This technique first fragments proteins into smaller peptides using an enzyme called trypsin. These sequences can then be compared to references in databases. The largest MS-based studies on bacteria have focused on just a handful of species, so a team of researchers recently created a resource for mapping data onto a more diverse population of bacteria.

Miriam Abele, Armin Soleymaniniya and colleagues at the Technical University of Munich developed MS2Bac, a software system that enables bacterial identification from protein data. They published their resource in Molecular & Cellular Proteomics. MS2Bac maps tryptic peptides onto reference bacterial species or strains, achieving almost perfect accuracy for species identification. To develop this tool, the team first performed MS on the proteins from over 300 bacterial species to create a reference database. They also compared their identification method with other approaches, such as Fourier transform infrared spectroscopy, and found that MS2Bac was the most accurate.

MS2Bac can also identify specific proteins, antibiotic resistance markers. It covers many hypothetical proteins, which are not well understood, providing a basis for further functional studies. This is the first study to incorporate single-cell organisms into the ProteomicsDB database, a proteomics resource for multiomics analyses. This tool will greatly help researchers and clinicians determine bacterial species from clinically and environmentally relevant samples.