Multiparametric Quantitation of the Bacillus cereus Toxins Cereulide and Isocereulides A-G in Foods.
Consumption of food products contaminated with cereulide (1), a toxin produced by Bacillus cereus, might cause intoxications with symptoms reported to range from indigestion pain and emesis to death. Recently, a series of structural variants, coined isocereulides A-G (2-8), were identified for the first time to be produced along with cereulide (1). The observation that isocereulide A (2) shows an ∼ 8-fold increased cytotoxicity when compared to 1 urges the development of analytical tools enabling an accurate quantitation of these toxins. Therefore, a rapid, sensitive, and robust stable isotope dilution assay (SIDA) was developed for the combined quantitation of 1-8 by means of UPLC-MS/MS. On average, trueness and precision of the method were 112.5 ± 1.8% RSD, repeatability and reproducibility were 2 and 4% for cereulide and isocereulides A-G, and the LOD and LOQ of 0.1 and 0.5 ng/g, respectively, demonstrated a high sensitivity for the developed SIDA method. Application of this method to food samples revealed elevated levels of 1-8 in two suspicious noodle samples, for example, ranging from 0.59 (7) to 189.08 ng/g (1) in sample 1 and from 5.77 (7) to 6198.17 ng/g (1) in sample 2, whereas the analysis of 25 randomly selected food samples, which have not been the subject to any complaints, did not contain detectable amounts of any of these toxins. As a consequence, this SIDA method could add an important contribution to the knowledge-based risk assessment of B. cereus toxins in foods.
Sandra
S
Marxen
Timo D
TD
Stark
Andrea
A
Rütschle
Genia
G
Lücking
Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna , 1210 Vienna, Austria.
Elrike
E
Frenzel
Chair of Microbial Ecology, Department of Biosciences, WZW, Technische Universität München , 85350 Freising, Germany.
Siegfried
S
Scherer
Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna , 1210 Vienna, Austria.
Monika
M
Ehling-Schulz
Thomas
T
Hofmann
D001409:Bacillus cereus / Q000378:metabolism*; D001427:Bacterial Toxins / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D047630:Depsipeptides / Q000032:analysis* / Q000096:biosynthesis / Q000633:toxicity; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology; D006801:Humans; D007201:Indicator Dilution Techniques; D007554:Isotopes; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry
D001427:Bacterial Toxins; D047630:Depsipeptides; D007554:Isotopes; C089294:cereulide; C000606082:isocereulide A
Bacillus cereus; cereulide; isocereulides; risk assessment; stable isotope dilution analysis