Optimization of matrix assisted desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) for the characterization of Bacillus and Brevibacillus species

Abstract

Graphical abstract

MALDI‐TOF mass spectrometry analysis of proteins and lipids in Escherichia coli exposed to copper ions and nanoparticles

“…To this aim, the present work focuses on obtaining protein and lipid profiles of cell membranes from bacterial strains treated with copper antimicrobial agents, such as soluble salts (chosen as reference) and in house synthetized copper nanoparticles (CuNPs) by using a mass spectrometry (MS) technique. Among MS techniques, matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) has shown its ability in providing useful information for microorganisms identification and differentiation, typically through peptide/protein fingerprinting, because of its speed and sensitivity that allow rapid analyses with minimal sample preparation …”

“…Among MS techniques, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) has shown its ability in providing useful information for microorganisms identification and differentiation, typically through peptide/protein fingerprinting, because of its speed and sensitivity that allow rapid analyses with minimal sample preparation. [23][24][25] Indeed, two commercial MALDI-TOF MS systems are today available for microbial identification: the Bruker MALDI Biotyper (Bruker Daltonics, Billerica, MA) and the bioMe´rieux VITEK MS (bioMe´rieux, Durham, NC). Highly abundant proteins with characteristic patterns are measured and used to reliably identify a particular microorganism assigning a 'score value' (Bruker) or a 'confidence value' (bioMeŕ ieux) to each match based on the test organism's similarities to reference spectra.…”

Identification and typing of Vagococcus salmoninarum using genomic and proteomic techniques

“…On the contrary, the combined use of cluster analysis and the identification of biomarkers by means of the Mass‐Up and SPSS programs (Fernández‐Álvarez et al, ; López‐Fernández et al, ) allowed us grouping strains according to their taxonomic position and the typing of bacterial strains according to the intra‐ and interspecific variability of their protein spectra. Numerous studies have demonstrated that cluster analysis of MALDI‐TOF data is robust and reliable methods for discrimination of bacteria (AlMasoud, Xu, Nicolaou, & Goodacre, ; Fernández‐Álvarez et al, ; Kim et al, ; Starostin et al, ). Similarity levels of the V. salmoninarum strains tested in this study range from 87% to 92%, and eight species‐specific mass biomarkers at m/z 4,521.41, 4,845.06, 5,291.74, 6,229.97, 6,965.50, 9,043.02, 9,686.66 and 10,579.43 were detected in 100% of strains of V. salmoninarum (20 to 20 strains tested) regardless of their source of isolation or geographical area.…”

Foodomics for investigations of food toxins

“…[DR2]Therefore, development of specific, rapid and sensitive methods for analytical determination of food pathogens and identification and quantification of preformed toxins in food has attracted major interest of scientists, in particular those developing high-throughput foodomics methodologies (genomics, proteomics and metabolomics). [43][44][45] have been developed that paved the way for introduction of the MALDI-based MS identification of microbes in food as a routine. The major bottleneck for its further implementation in food monitoring remains the problem of incorrect interpretation due to presence or absence of unique peak patterns [46].…”