To prepare anti-Brucella abortus serum used for calibrate the agglutination test follwing the national standard, 4 anti-Brucella abortus sera were obtained from 4 cows infected with Brucella abortus naturally. By potency testing, the third serum was selected. Sterility, vaccum degree, residual moisture, uniformity and stability of this standard material were tested and proved to meet the national standard. Referring to the international standard, RBT (Rose-Bengal plate agglutination test), SAT (standard tube agglutination) and CFT (complement fixation test) titers of this standard material were measured to be 1:160 "+" 1:2 400 "++" and 1:800 "++", which are identical with the collaborative assay results. International unit of the standard material is 4 000 IU/mL.
Agglutination Tests ; veterinary ; Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; immunology ; Brucella abortus ; immunology ; Brucellosis, Bovine ; diagnosis ; Cattle ; China ; Complement Fixation Tests ; veterinary ; Immune Sera ; Reference Standards

The Brucella mdh gene was successfully cloned and expressed in E. coli. The purified recombinant malate dehydrogenase protein (rMDH) was reactive to Brucella-positive bovine serum in the early stage, but not reactive in the middle or late stage, and was reactive to Brucella-positive mouse serum in the late stage, but not in the early or middle stage of infection. In addition, rMDH did not react with Brucella-negative bovine or mouse sera. These results suggest that rMDH has the potential for use as a specific antigen in serological diagnosis for early detection of bovine brucellosis.
Animals ; Antigens, Bacterial/*immunology ; Brucella abortus/*enzymology/immunology ; Brucellosis/diagnosis/*veterinary ; Cattle ; Cattle Diseases/*diagnosis ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli/genetics ; Malate Dehydrogenase/*genetics/*immunology/isolation & purification ; Mice ; Recombinant Proteins/genetics/*immunology