University of Veterinary Medicine Vienna - Research portal

Diagrammed Link to Homepage University of Veterinary Medicine, Vienna

Selected Publication:

Publication type: Journal Article
Document type: Full Paper

Year: 2015

Author(s): Marxen, S; Stark, TD; Frenzel, E; Rütschle, A; Lücking, G; Pürstinger, G; Pohl, EE; Scherer, S; Ehling-Schulz, M; Hofmann, T

Title: Chemodiversity of cereulide, the emetic toxin of Bacillus cereus.

Source: Anal Bioanal Chem. 2015; 407(9):2439-2453



Authors Vetmeduni Vienna:

Ehling-Schulz Monika
Frenzel Elrike
Macher Gabriel
Pohl Elena

Vetmed Research Units
Institute of Microbiology, Functional Microbiology Division
Institute of Physiology, Pathohysiology and Biophysics, Unit of Physiology and Biophysics


Abstract:
Food-borne intoxications are increasingly caused by the dodecadepsipeptide cereulide, the emetic toxin produced by Bacillus cereus. As such intoxications pose a health risk to humans, a more detailed understanding on the chemodiversity of this toxin is mandatory for the reliable risk assessment of B. cereus toxins in foods. Mass spectrometric screening now shows a series of at least 18 cereulide variants, among which the previously unknown isocereulides A-G were determined for the first time by means of UPLC-TOF MS and ion-trap MS(n) sequencing, (13)C-labeling experiments, and post-hydrolytic dipeptide and enantioselective amino acid analysis. The data demonstrate a high microheterogeneity in cereulide and show evidence for a relaxed proof reading function of the non-ribosomal cereulide peptide synthetase complex giving rise to an enhanced cereulide chemodiversity. Most intriguingly, the isocereulides were found to differ widely in their cell toxicity correlating with their ionophoric properties (e.g., purified isocereulide A showed about 8-fold higher cytotoxicity than purified cereulide in the HEp-2 assay and induced an immediate breakdown of bilayer membranes). These findings provide a substantial contribution to the knowledge-based risk assessment of B. cereus toxins in foods, representing a still unsolved challenge in the field of food intoxications.

Keywords Pubmed: Bacillus cereus/chemistry*
Bacterial Toxins/analysis*
Bacterial Toxins/toxicity
Cell Survival/drug effects
Chromatography, High Pressure Liquid
Depsipeptides/analysis*
Depsipeptides/toxicity
Emetics/analysis*
Emetics/toxicity
Hep G2 Cells
Humans
Mass Spectrometry


© University of Veterinary Medicine ViennaHelp and Downloads