COMPARISON OF BIOLOGICAL EFFECT OF THE 2 DIFFERENT ENTEROTOXIN COMPLEXES ISOLATED FROM 3 DIFFERENT STRAINS OF BACILLUS-CEREUS

The cytotoxicity of the two different enterotoxin complexes of Bacillu s cereus was compared after isolation from three different strains. Pr otein components of non-haemolytic enterotoxin (NHE) of 39 kDa, 45 kDa and 105 kDa were isolated from all of the three strains, whilst prote ins B, L-1 and L-2 of haemolysin BL (HBL) were isolated from supernata nts of two strains (F837-76 and 1230-88). These proteins were not dete cted in strain 0075-95. Inhibition of protein synthesis in Vero cells was used as a measure of cytotoxicity. The HBL complex from strain F83 7-76 was highly toxic. This strain also produced the NHE complex. Howe ver, when purified, at least two of the components of NHE had to be pr esent in higher amounts than those of the components of HBL to cause t he same degree of toxicity. Both complexes purified from strain 1230-8 8 were cytotoxic. The amount required to cause the same degree of cyto toxicity was approximately equal for the components of the two complex es, except that higher amounts of the 105 kDa protein of NHE had to be present than for the other components. None of the purified complexes from strain 1230-88 was toxic in amounts comparable to those of the H BL complex of strain F837-76 and NHE of strain 0075-95. These results indicate that when measuring cytotoxic enterotoxins from B. cereus at least two different complexes and six different proteins have to be ta ken into consideration.