COMPARISON OF DIFFERENT PURIFICATION PROCEDURES FOR EXTRACTION OF STAPHYLOCOCCAL ENTEROTOXIN-A FROM FOODS

Different procedures commonly used for extraction, purification and concentration of staphylococcal enterotoxins from foods were investigated with 131I- and 125I-labeled staphylococcal enterotoxin A. Loss of labeled enterotoxin A was compared with loss of total N. In most of the common procedures, such as gel filtration, ion exchange and heat treatment, the percentage of loss of labeled enterotoxin A was greater than the loss of total N. Chloroform extraction and acid precipitation with HCl had nearly the same effect on the purification of labeled enterotoxin A and total N. (NH4)2SO4 precipitation was practical and was successfully used for purification of enterotoxin A from sausage extract. Simultaneous use of trypsin and Pseudomonas peptidase for treatment of food extracts considerably reduced food proteins capable of interfering with serological detection of enterotoxins but did not essentially influence the loss of enterotoxin A.