Persistência de anticorpos aglutinantes e fixadores de complemento em bezerras vacinadas com Brucella Abortus amostra B19.

Abstract

The results of an experiment to invetigate the presistence of agglutinanting and fixing complement antibodies in seventeen female calves, 3 to 18 months old, vaccinated with Brucella abortus strain 19 under field conditions, are reported. The animals were sampled for serum in the day of vaccination and thereafterup to 364 days. The sera were examined by the plate agglutination (PA T), complement fixation (CFT) and Rose Bengal plate tests (RBPT). Six days after vaccination all the 17 animals showed agglutination titre between 1 in 25 and 1 in 400 in the PAT and the higher average occurred at the 14tn day after vaccination. Theree hundred and sixty four days after vaccination a single animal, vaccinated at 11 months old, showed titre 1 in 50 in the PAT. Fourteem days after vaccination all animals revealed titres in the CFT and the highest average occurred at the 17tn day. One hundred and sixty days after vaccination a single animal showed fixing complement titre that persisted until the end of the experiment, this same animal maintained for more time the agglutination titre in the PA T. Six days after vaccination 14 out of 17 animals showed positive results to the RBPT. Fourteen days after vaccination all animals were positives to the RBPT but the antibody was no longer detdctable after 259 days. For the three serological tests there was a rapid decrease in the antibody levels but one animal maintained the titre for more time.