Pathogenic Properties of Bacilli not Belonging to the B. cereus Group

Bacilli other than members of the B. cereus group are only rarely associated with food spoilage, such as ropy bread and incidents of foodborne gastroenteritis. Toxin-producing strains of B. licheniformis, a normally harmless contaminant in dairy products, have been related to a few food poisoning incidents. These strains have been isolated from raw milk and industrially produced baby food [34]. The toxigenic B. licheniformis strains are biochemically indistinguishable from type strain DSM13 , but produce a toxin that is similar in many physicochemical properties to cereulide, the emetic toxin of B. cereus. Cereulide is a dodecadepsipeptide structurally resembling valinomycin. This peptide toxin is nonribosomally synthesized, and B. licheniformis as well as many other Bacillus spp. are known to produce several peptides such as the antibiotics bacitracin and amoebicin. B. lichenifo-mis is used to produce industrial enzymes on a large scale, and has the recognized-as-safe status with the United States Food and Drug Administration. The recently finished genome project for B.lichenifomis DSM13 confirmed the absence of described virulence factors [35, 36] in addition to the known ability to form a poly-y-D-glutamate capsule that has been described as an important virulence factor in B. anthracis [37]. Most notably, the cereulide biosynthetic genes are absent in this strain.

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