Protective Effect of Sera from Animals Treated with Different Brucella Antigens upon Brucella Infection in Mice

[摘要] Sera from adult cattle injected with ether-killed Brucella abortus combined with Falba and mineral oil showed a much higher protective action against lethal Brucella infection in mice than sera from cattle injected with live strain 19 vaccine of Br. abortus . The agglutinin titers of the 2 groups of animals were very similar at the time of the in-vivo test in mice.A small percentage of sera from heifers injected with live strain 19 vaccine within 2 years of the time of the test protected mice against lethal Brucella infection, while none of the sera from animals immunized at longer intervals before the time of testing protected all treated mice.Sera from guinea pigs injected with ether-killed Br. abortus combined with Falba and mineral oil conferred considerable protection on mice in all 4 tests carried out in the course of the 6½ months. Sera from guinea pigs injected with the same dose of ether-killed Br. abortus suspended in saline, on the other hand, showed only slight protection in the first test, and in the subsequent tests none of the sera protected all mice.Sera from guinea pigs infected with virulent Br. abortus showed protective activity which fluctuated in the various tests. Variation in clinical symptoms of brucellosis may possibly be related to such changes in the concentration of humoral protective substance.The various sera protected mice against the lethal effect of a large infecting dose, but did not suppress chronic infection.

[学科分类] 生物科学（综合）