Multiparametric Quantitation of the Bacillus cereus Toxins Cereulide and Isocereulides A–G in Foods

• Published in: Journal of agricultural and food chemistry Vol. 63; no. 37; pp. 8307 - 8313
• Main Authors: Marxen, Sandra, Stark, Timo D, Rütschle, Andrea, Lücking, Genia, Frenzel, Elrike, Scherer, Siegfried, Ehling-Schulz, Monika, Hofmann, Thomas
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 23.09.2015
• Subjects: Bacillus cereus; Bacillus cereus - metabolism; Bacterial Toxins - analysis; Chromatography, High Pressure Liquid; cytotoxicity; death; Depsipeptides - analysis; Depsipeptides - biosynthesis; Depsipeptides - toxicity; Food Contamination - analysis; food intake; Food Microbiology; Foodborne Diseases - microbiology; Humans; Indicator Dilution Techniques; indigestion; isotope dilution technique; Isotopes; noodles; pain; Reproducibility of Results; risk assessment; Sensitivity and Specificity; stable isotopes; Tandem Mass Spectrometry; toxins; risk assessment; isocereulides; Bacillus cereus; stable isotope dilution analysis; cereulide
• ISSN: 0021-8561; 1520-5118; 1520-5118
• DOI: 10.1021/acs.jafc.5b03705

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.