Real-time-PCR-System for detection of Bacillus cereus (emetic type) in the food.

@enBacillus cereus is a Gram-positive, facultative anaerobic, spore-performing bacterium. Some B. cereus strains have the ability to produce two different types of toxins: (a) diarrhoeic toxin: the disease is similar to a C. perfringens toxin-infection; it is caused by a heat-labile protein, (b) emetic toxin: the disease is similar to Staphylococcus-aureus intoxikation; it is caused by a heat-stable protein. Statements about the frequency of B. cereusfood-poisonings are difficult because a reporting system for this disease is missing in Germany and there exists no valid methodology to diagnose this disease with conventional microbiological or biochemical methods. Nevertheless B. cereus, beside S. aureus, seems to be the most important bacterium to cause food-associated intoxications. The detection of emetic toxin directly in food is difficult, time consuming and expensive (HPLC-MS) and so a real-time-PCR assay including an Intern Amplification Control (IAC) for the detection of emetic B. cereus was developed and tested with different food matrices and routine samples. The assay is a rapid and reliable detection system for the routine laboratory to confirm in combination with microbiological methods (plating, colony-counting or enrichment) the suspicion of a food-associated B. cereus intoxication. This is a great progress from the epidemiological and legal point of view, particularly as a first diagnosis can be given after 30 hours. In addition it will be possible to make a risk assessment for different food products in order to protect the consumers' health, because investigations can be performed more easily and frequently.