title: Bacillus cereus Group-Type Strain-Specific Diagnostic Peptides.
abstract: The Bacillus cereus group consists of eight very closely related species and comprises both harmless and human pathogenic species such as Bacillus anthracis, Bacillus cereus, and Bacillus cytotoxicus. Numerous efforts have been undertaken to allow presumptive differentiation of B. cereus group species from one another. However, methods to rapidly and accurately distinguish these species are currently lacking. We confirmed that classical matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) biotyping cannot achieve reliable identification of each type strain. We therefore assigned type strain-specific diagnostic peptides to the B. cereus group based on comparisons of their proteomic profiles. The number of diagnostic peptides varied remarkably in a type strain-dependent manner. The accuracy of the reference database was crucial to validate candidate diagnostic peptides and led to a noteworthy reduction of verified diagnostic peptides. Diagnostic peptides ranged from one for B. weihenstephanensis to 62 for B. pseudomycoides and were associated with proteins involved in diverse biological processes, e.g. amino acid biosynthesis, cell envelope, cellular processes, energy metabolism, and transport processes. However, 45.6% of all diagnostic peptides comprised currently unclassified proteins or proteins of unknown function. In addition, a phylogenetic tree based on clustering of theoretical precursor masses deduced from in silico-generated tryptic peptides was reconstructed.
authors.affiliation: Agroscope , Institute for Food Sciences, Schloss 1, 8820 Waedenswil, Switzerland.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Pfrunder
authors.affiliation: Functional Genomics Center Zurich, ETH Zurich and University of Zurich , Winterthurerstraße 190, 8057 Zurich, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Grossmann
authors.affiliation: Functional Genomics Center Zurich, ETH Zurich and University of Zurich , Winterthurerstraße 190, 8057 Zurich, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Hunziker
authors.affiliation: Functional Genomics Center Zurich, ETH Zurich and University of Zurich , Winterthurerstraße 190, 8057 Zurich, Switzerland.
authors.forename: René
authors.initials: R
authors.lastname: Brunisholz
authors.affiliation: Agroscope , Institute for Food Sciences, Schloss 1, 8820 Waedenswil, Switzerland.|ETH Zurich , Institute of Food, Nutrition and Health, Schmelzbergstraße 7, 8092 Zurich, Switzerland.
authors.forename: Maria-Theresia
authors.initials: MT
authors.lastname: Gekenidis
authors.affiliation: Agroscope , Institute for Food Sciences, Schloss 1, 8820 Waedenswil, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Drissner
mesh_terms: D001407:Bacillus / Q000737:chemistry; D001409:Bacillus cereus / Q000737:chemistry*; D001426:Bacterial Proteins / Q000032:analysis*; D015373:Bacterial Typing Techniques / Q000379:methods*; D010455:Peptides / Q000032:analysis*; D010802:Phylogeny; D040901:Proteomics / Q000379:methods; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D010455:Peptides
keywords: Bacillus cereus group; diagnostic peptides; mass spectrometry; type strains