Immunological assay after vaccination of goats with Brucella melitensis Rev. I and Brucella abortus 45/20 vaccines at Saudi Arabia.
The living smooth Brucella melitensis Rev. I vaccine given in the normal dose (7x10(8) organism) to goats 3 to 5 months of age stimulated a marked increase in agglutinin titer. Fractionation of pools of serum by gel filtration by anion exchange chromatography, using diethylaminoethyl (DEAE -) cellulose showed that both IgM and IgG agglutinins were present from 12 to 47 days after goats were vaccinated. Only mercaptoethanol (ME)-sensitive agglutinins were detected in most goats 4 months after vaccination, but 2 of 30 goats retained ME-resistant agglutinins for the 13 1/2 - month observation period. Fractionation of serums from goats representative of these 2 types of serologic response indicated that most goats had only IgM agglutinins, whereas the 2 given goats had activity in the IgG fraction. Adult goats given Brucella abortus 42/20 adjuvant vaccine and revaccinated 5 months later developed low agglutination titers to smooth antigen, and all became test positive to the antiglobulin test. Fractionation of serum of pools taken 1 week and 8 months after revaccination indicated that antibody activity was restricted to the IgG fraction. Sera from 5 vaccinated and nonvaccinated goats which were positive by bacteriological culture examination at necropsy 31 to 47 days after goats were given conjunctival inoculation of virulent B. melitensis had antibody activity in both IgG and IgM fractions. Test positive reaction to the ME, complement-fixation (CF), and antiglobulin (AG) test were restricted to the IgG-containing fractions of serum, whereas reactions to the agglutination (STT) and the card tests appeared with either or both fractions. The effect of these findings on the choice of tests for the differentiation of vaccination response is discussed.