DETECTION OF TOXINOGENIC BACILLUS-CEREUS

Investigations into optimal culture conditions for Bacillus cereus in order to detect bacterial toxins in a cell culture system showed that Dulbecco's modified Eagle's medium supplemented with 5% fetal calf ser um is the medium best suited for this purpose. The highest toxicity le vels were seen when bacteria were cultured at 21 degrees C. In 42 of 4 3 Bacillus cereus-strains isolated from milk and milk products, toxin formation was detected using the MTT-test. In 11 strains, toxin format ion was even shown when bacteria were cultured at 4 degrees C. When cu lture supernatants were examined in a commercially available ELISA, al l cytotoxic strains were shown to form diarrheal toxin.