Detection of emetic Bacillus cereus and the emetic toxin cereulide in food matrices: Progress and perspectives

Cereulide, a potent toxin produced by emetic Bacillus cereus (B. cereus), is a small, heat- and acid-stable cyclic dodecadepsipeptide known as a potassium-selective ionophore. Recently, cereulide is responsible for an increasing number of foodborne poisonings due to changes in lifestyle and eating habits. As such, the development of analytical methods for precise, rapid, and efficient detection of cereulide is necessary and urgently required for the health and safety of humans. The information currently available on the physicochemical properties and metabolic pathways of cereulide are briefly presented. The analytical methods for qualitative and quantitative detection of cereulide are presented and discussed with special emphasis on the inherent advantages and disadvantages of these methods. Investigating cereulide contamination requires detection of emetic B. cereus, cereulide, and/or its biomarkers. The primary method used for detection of emetic B. cereus is polymerase chain reaction, while whole genome sequencing is expected to become an alternative method in the future. PCR remains the gold standard for emetic B. cereus determination and liquid chromatography coupled with mass spectrometry is widely accepted for cereulide quantification, while emerging techniques such as fluorescence and immunoassay have also been applied to detect cereulide and its biomarkers. It is also necessary to develop rapid screening methods to enhance the detection of cereulide in large numbers of samples.