Characterization of Bacillus cereus sensu lato isolates from consumers milk; potential for spoilage and disease

The presence of the Bacillus cereus group in fresh milk before and after pasteurization is regarded as a potential quality and safety hazard. This study addresses the biodiversity of Bacillus cereus group isolates present along the value chain of consumption milk. Bacillus cereus group isolates were collected from two dairies in Norway from raw milk, after pasteurization and throughout the storage period at 4 or 8°C. Storage at 8°C caused a major shift in the composition of the B. cereus group population. Mesophilic strains dominated the population in raw milk and after storage at 4°C while psycrotrophic strains dominated after storage at 8°C.