Resposta imune humoral de bubalinos (Bubalus bubalis) vacinados pela cepa B19 de Brucella abortus

Abstract

Brucellosis is spread throughout the country, with the highest prevalence for the strain Brucella abortus that despite being endemic presents unevenly among different regions of Brazil. This study aims to evaluate the humoral and immune response of buffalo calves raised in the Middle Amazon Mesoregion, Pará state, vaccinated with B19 strain of B. abortus according the age recommended by the National Program for the Control and Eradication of Brucellosis and Tuberculosis (PNCEBT). Thirty-six female (test group) and six males (control group) aged 3-8 months were selected and monitored. On day 0 of the experiment, blood was collected from all animals, then all females received commercial vaccine with standard-dose sample B19 as recommended by PNCEBT with subsequent blood samples were taken at 30, 60, 90, 120, 150, 180, 210, 330, 360 and 390 days, respectively. The blood serums were evaluated for evidence of agglutination screening through Buffered Acidified Antigen - AAT and the confirmatory test through 2 Mercaptoethanol - 2ME. The results for all samples collected on day 0 were negative in the reaction, however at 30 and 60 days all females were 100% positive through test reaction AAT and titration 1:200, starting the decline through the titration at 90 days in both events. Females at 210 days still present reagents with similar results in both tests, however only one animal remained reactive in both tests up to 360 days. After 390 days of the begin of the experiment 100% of the females had a negative reaction in both events and throughout the experiment males were negative. Thus, by the evaluation of results, vaccination was effective for immunization, as well as an important tool in the prophylaxis of brucellosis in the species studied, as well as the tests applied to the diagnosis of this disease in buffaloes species at regional level.