title: Rapid identification of bacterial isolates from wheat roots by high resolution whole cell MALDI-TOF MS analysis.
abstract: Whole-cell mass spectrometry analysis is a powerful tool to rapidly identify microorganisms. Several studies reported the successful application of this technique to identify a variety of bacterial species with a discriminatory power at the strain level, mainly for bacteria of clinical importance. In this study we used matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) to assess the diversity of wheat-associated bacterial isolates. Wheat plants cultivated in non-sterile vermiculite, under greenhouse conditions were used for bacterial isolation. Total cellular extracts of 138 isolates were analyzed by MALDI-TOF MS and the mass spectra were used to cluster the isolates. Taxonomic identification and phylogenetic reconstruction based on 16S rRNA gene sequences showed the presence of Pseudomonas, Pantoea, Acinetobacter, Enterobacter and Curtobacterium. The 16S rRNA gene sequence analyses were congruent with the clusterization from mass spectra profile. Moreover, MALDI-TOF whole cell mass profiling allowed a finer discrimination of the isolates, suggesting that this technique has the potential of differentiating bacterial isolates at the strain level.
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Paraná (UFPR), CP 19046, 81.531-990 Curitiba, PR, Brazil.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Stets
authors.forename: Artur Soares
authors.initials: AS
authors.lastname: Pinto
authors.forename: Luciano Fernandes
authors.initials: LF
authors.lastname: Huergo
authors.forename: Emanuel Maltempi
authors.initials: EM
authors.lastname: de Souza
authors.forename: Vandeir Francisco
authors.initials: VF
authors.lastname: Guimarães
authors.forename: Alexessander Couto
authors.initials: AC
authors.lastname: Alves
authors.forename: Maria Berenice Reynaud
authors.initials: MB
authors.lastname: Steffens
authors.forename: Rose Adele
authors.initials: RA
authors.lastname: Monteiro
authors.forename: Fábio de Oliveira
authors.initials: Fde O
authors.lastname: Pedrosa
authors.forename: Leonardo Magalhães
authors.initials: LM
authors.lastname: Cruz
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000032:analysis; D017343:Genes, Plant / Q000235:genetics; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D059010:Single-Cell Analysis / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014908:Triticum / Q000382:microbiology*
chemical_list: D018744:DNA, Plant; D012336:RNA, Ribosomal, 16S