Occurrence and toxicity of Bacillus cereus in spices
Summary of a presentation of 44. Kulmbacher week 2009
B. cereus is one of the most important causes of deterioration in the quality and spoilage of food. In addition, the importance of toxin-producing B. cereus strains is growing as a trigger of food-borne diseases that can cause two forms of gastrointestinal disease: diarrheaic syndrome and emetic syndrome. In complex foods, spices are often viewed as vectors for B. cereus contamination. However, hardly any studies have been published on spices as a possible source of B. cereus in food. There is also little current data from the European area on the actual contamination of spices with this pathogen.The aim of this work was to analyze the occurrence and toxicity of B. cereus in spices in order to obtain an up-to-date overview of the contamination with this pathogen for an assessment of the microbiological safety of spices.
For this purpose, a total of 60 spice samples from twelve different types of spices were first examined for contamination with presumptive B. cereus using culture methods. Potential B. cereus were then further characterized with regard to their toxicity using PCR, immunochemical detection methods (ELISA, RPLA) and cell culture tests. At the same time, the general microbiological status with regard to aerobic, mesophilic total bacterial count and Enterobacteriaceae contamination was recorded.
The number of presumptive B. cereus in the spice products was between 10 and 1000 CFU/g in about two thirds of the samples and below 10 CFU/g in about one third. The guideline value for B. cereus in spices of 10 recommended by the DGHM and the European Commission was not exceeded in any spice3 CFU/g exceeded.
From 49 spice samples, 171 presumptive B. cereus strains were isolated, of which 151 could be confirmed as B. cereus. Approximately 80 percent of these isolates exhibited toxin-producing ability: 5 percent had emetic toxin-producing ability and 76 percent had diarrheal toxinogenicity.
The lectures of the Kulmbach Week are fully documented in the newsletter of the sponsoring society for meat research in Kulmbach.
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Source: Kulmbach [ PICHNER, R., A. HAMMON and M. GAREIS ]
