Prevalence of Emetic Bacillus cereusin Different Ice Creams in Bavaria

In this study, 809 samples of ice cream from different sources were investigated by using cultural methods for the presence of presumptive Bacillus cereus. Isolates from culture-positive samples were examined with a real-time PCR assay targeting a region of the cereulide synthetase gene (ces) that is highly specific for emetic B. cereusstrains. The samples were collected from ice cream parlors and restaurants that produced their own ice cream and from international commercial ice cream companies in different regions of Bavaria during the summer of 2008. Presumptive B. cereuswas found in 508 (62.7%) ice cream samples investigated, and 24 (4.7%) of the isolates had the genetic background for cereulide toxin production. The level of emetic B. cereusin the positive samples ranged from 0.1 to 20 CFU/g of ice cream.