title: Species differentiation of seafood spoilage and pathogenic gram-negative bacteria by MALDI-TOF mass fingerprinting.
abstract: Species differentiation is important for the early detection and identification of pathogenic and food-spoilage microorganisms that may be present in fish and seafood products. The main 26 species of seafood spoilage and pathogenic Gram-negative bacteria, including Aeromonas hydrophila, Acinetobacter baumanii, Pseudomonas spp., and Enterobacter spp. among others, were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) of low molecular weight proteins extracted from intact bacterial cells by a fast procedure. From the acquired spectra, a library of specific mass spectral fingerprints was constructed. To analyze spectral fingerprints, peaks in the mass range of 2000-10 000 Da were considered and representative mass lists of 10-35 peak masses were compiled. At least one unique biomarker peak was observed for each species, and various genus-specific peaks were detected for genera Proteus, Providencia, Pseudomonas, Serratia, Shewanella, and Vibrio. Phyloproteomic relationships based on these data were compared to phylogenetic analysis based on the 16S rRNA gene, and a similar clustering was found. The method was also successfully applied for the identification of three bacterial strains isolated from seafood by comparing the spectral fingerprints with the created library of reference fingerprints. Thus, the proteomic approach demonstrated to be a competent tool for species identification.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences, University of Santiago de Compostela, Lugo, Spain.
authors.forename: Karola
authors.initials: K
authors.lastname: Böhme
authors.forename: Inmaculada C
authors.initials: IC
authors.lastname: Fernández-No
authors.forename: Jorge
authors.initials: J
authors.lastname: Barros-Velázquez
authors.forename: José M
authors.initials: JM
authors.lastname: Gallardo
authors.forename: Pilar
authors.initials: P
authors.lastname: Calo-Mata
authors.forename: Benito
authors.initials: B
authors.lastname: Cañas
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000145:classification*; D015415:Biomarkers / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis; D005516:Food Microbiology; D006090:Gram-Negative Bacteria / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D008970:Molecular Weight; D010449:Peptide Mapping / Q000379:methods*; D010802:Phylogeny; D040901:Proteomics / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017747:Seafood / Q000382:microbiology*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D015415:Biomarkers; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S