Lund Terje, Granum Per Einar
Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine, PO Box 8146 Dep., N-0033 Oslo, Norway.
Microbiology (Reading). 1997 Oct;143 ( Pt 10):3329-3336. doi: 10.1099/00221287-143-10-3329.
The cytotoxicity of the two different enterotoxin complexes of Bacillus cereus was compared after isolation from three different strains. Protein components of non-haemolytic enterotoxin (NHE) of 39 kDa, 45 kDa and 105 kDa were isolated from all of the three strains, whilst proteins B, L1 and L2 of haemolysin BL (HBL) were isolated from supernatants of two strains (F837-76 and 1230-88). These proteins were not detected in strain 0075-95. Inhibition of protein synthesis in Vero cells was used as a measure of cytotoxicity. The HBL complex from strain F837-76 was highly toxic. This strain also produced the NHE complex. However, when purified, at least two of the components of NHE had to be present in higher amounts than those of the components of HBL to cause the same degree of toxicity. Both complexes purified from strain 1230-88 were cytotoxic. The amount required to cause the same degree of cytotoxicity was approximately equal for the components of the two complexes, 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 HBL 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 taken into consideration.
从三种不同菌株中分离出蜡样芽孢杆菌的两种不同肠毒素复合物后，对其细胞毒性进行了比较。从所有三种菌株中均分离出了非溶血肠毒素（NHE）的39 kDa、45 kDa和105 kDa的蛋白质成分，而溶血素BL（HBL）的蛋白质B、L1和L2则从两种菌株（F837 - 76和1230 - 88）的上清液中分离得到。在菌株0075 - 95中未检测到这些蛋白质。使用Vero细胞中蛋白质合成的抑制作为细胞毒性的衡量指标。来自菌株F837 - 76的HBL复合物具有高毒性。该菌株也产生NHE复合物。然而，纯化后，NHE的至少两种成分的含量必须高于HBL成分，才能引起相同程度的毒性。从菌株123中纯化得到的两种复合物均具有细胞毒性。除了NHE的105 kDa蛋白质需要比其他成分存在更高的量外，两种复合物的成分引起相同程度细胞毒性所需的量大致相等。来自菌株1230 - 88的纯化复合物中，没有一种在与菌株F837 - 76的HBL复合物和菌株0075 - 95的NHE相当的量下具有毒性。这些结果表明，在测定蜡样芽孢杆菌的细胞毒性肠毒素时，至少必须考虑两种不同的复合物和六种不同的蛋白质。
