Study On Extraction And Some Immune Characteristics Of The Staphylococcal Enterotoxins For Milk Cows

Bovine mastitis is a familiar disease of milk cows. And it is one of the mostly diseases to harm the word milk industry. It makes the output of milk drop, infection the quality of milk, endangering the peoples'health and makes graveness expense of economy. In the clinic and recessive infection of animal, Staphylococcus aureus is a kind of important bacterial pathogeny. The incidence of a disease is descending of bovine mastitis for Staphylococcus aureus due to the application of antibiotics, but insensitive bacterium is increasing. The conventional bacterin of Staphylococcus aureus include dead bacterin, dilute live bacterin, metamorphic toxin bacterin and bacterin of cellular wall element for testing bacterium, but these attempts have not afford distinct protection for resisting bovine mastitis as a result of different character Staphylococcus aureus. Staphylococcal enterotoxins are a kind of mitotic substance for clone T cells, and it haven't special character. Staphylococcal enterotoxins have good foreground in developing new-style bacterin for prevention bovine mastitis of Staphylococcus aureus.The study identified 43 milks by the test of 3%H2O2, the test of coagulase and the test of biochemistry characteristic. 9 strains of Staphylococcus aureus were in the 43 milks, the rate of masculine was 20.93%(9/43).The drug sensitive test shows that the isolates were insensitive to Penicillin, Ampicillin, Lincomycin and Polymycin B sulfate, and were sensitive to Streptomycin, Cephalosporins, Florfenicol, Ofloxacin, Sulphadiazine, Oxytetracycline and Kanamycin.Distilling Staphylococcal enterotoxins by the method of liquid-dialyse- cultivating, and then determining the content in the liquid. The content of Staphylococcal enterotoxins in the liquid is 33.27mg/ml. One of the nine strains only produces one kind of Staphylococcal enterotoxins, the proportion is 11.11%(1/9);Eight strains produce more two kinds of Staphylococcal enterotoxins, the proportion is 88.89 % (8/9); Four strains produce Staphylococcal enterotoxin A, the proportion is 44.44%(4/9); Producing Staphylococcal enterotoxin B and E of Staphylococcus aureus were all three strains, the propotion is 33.33%(3/9); Five strains produce Staphylococcal enterotoxin C, the proportion is 55.55%(5/9); Six strains produce Staphylococcal enterotoxin D, the proportion is 66.66%(6/9).