Characterization and Exposure Assessment of Emetic Bacillus cereusand Cereulide Production in Food Products on the Dutch Market

The emetic toxin cereulide, which can be produced by Bacillus cereus, can be the cause of food poisoning upon ingestion by the consumer. The toxin causes vomiting and is mainly produced in farinaceous food products. This article includes the prevalence of B. cereusand of cereulide in food products in The Netherlands, a characterization of B. cereusisolates obtained, cereulide production conditions, and a comparison of consumer exposure estimates with those of a previous exposure assessment. Food samples (n= 1,489) were tested for the presence of B. cereus; 5.4% of the samples contained detectable levels (>102CFU/g), and 0.7% contained levels above 105CFU/g. Samples (n= 3,008) also were tested for the presence of cereulide. Two samples (0.067%) contained detectable levels of cereulide at 3.2 and 5.4 μg/kg of food product. Of the 481 tested isolates, 81 produced cereulide and/or contained the cesgene. None of the starch-positive and hbl-containing isolates possessed the cesgene, whereas all strains contained the nhegenes. Culture of emetic B. cereusunder nonoptimal conditions revealed a delay in onset of cereulide production compared with culture under optimal conditions, and cereulide was produced in all cases when B. cereuscells had been in the stationary phase for some time. The prevalence of cereulide-contaminated food approached the prevalence of contaminated products estimated in an exposure assessment. The main food safety focus associated with this pathogen should be to prevent germination and growth of any B. cereuspresent in food products and thus prevent cereulide production in foods.