Rapid identification of environmental bacterial strains by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Abstract

In recent years, various mass spectrometry procedures have been developed for bacterial identification. The accuracy and speed with which data can be obtained by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) could make this a powerful tool for environmental monitoring. However, minor variations in the sample preparation can influence the mass spectra significantly. Therefore, the first objectives of this study were the adjustment and the optimization of experimental parameters allowing a rapid identification of whole bacterial cells without laborious sample preparation. The tested experimental parameters were matrix, extraction solvent, salt content, deposition method, culture medium and incubation time. This standardized protocol was applied to identify reference and environmental bacterial strains of Escherichia coli, Salmonella and Acinetobacter. The environmental bacterial strains were isolated from sewage sludge using an original microextraction procedure based on repeated sonications and enzymatic treatments. The bacterial identification was realized by the observation of the respective genus‐, species‐ and strain‐specific biomarkers. This bacterial taxonomy could be completed within one hour, with minimal sample preparation, provided that sufficient bacteria had been collected prior to MALDI‐TOF analysis. Copyright © 2004 John Wiley & Sons, Ltd.

Application of Whole-Cell Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Rapid Identification and Clustering Analysis ofPantoeaSpecies

“…Sequencing of housekeeping genes, MLSA, and fAFLP are labor-intensive, time-consuming, and impractical approaches as routine diagnostic tools. Whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (31) is an emerging technology for identification of bacteria (26,46), fungi (17,33), viruses (29,51), insects (41), and helminths (42). MALDI-TOF MS-based identification can accurately resolve bacterial identity at the genus, species, and in some taxa subspecies levels (e.g., Salmonella enterica serovars, Listeria genotypes) (1,18).…”

MALDI mass spectrometry analysis of high molecular weight proteins from whole bacterial cells: Pretreatment of samples with surfactants

“…Using this approach, bacterial protein profiling was simple and rapid (time Ͻ5 min). A majority of the early research published on whole cell bacterial MALDI analysis described protein profiles up to 30 kDa [2,3]. The signals in this range were attributed to cellular proteins or cell wall associated proteins [8,9].…”

An Evaluation Of Direct Identification Of Pathogens From Blood Cultures By Maldi-Tof Mass Spectrometry

“…Identification of microorganisms from positive blood culture using of MALDI Sepsity per processing kit requires approximately 20 minutes and it does independent of species (6, 10,13,18,20,25,26,32,33). Batch processing added approximately 1 min per blood culture analyzed.Our estimated time to identify bacteria from the positive blood culture, of fixed automated system BD BACTEC Fx signal time to MALDI-TOF mass spectrometry identification time, is not an objective, it includes the blood smear preparation time by Gram staining, …”

“…Lina Savickaitė, Jelena Kopeykinienė Klaipeda University Hospital, Lithuania sample preparation, matrix solutions and organic solvents, affect the quality and reproducibility of bacterial MALDI-TOF mass spectrometry fingerprints (11)(12)(13)(14)(15)(16). With a special set of MALDI Sepsityper is possible to identify bacteria directly from the positive blood culture (17)(18)(19)(20)(21)(22)(23)(24)(25).…”