Production and Evaluation of Immunoglobulin Y Anti-Brucella abortus (Vaccinal Strain B19)
Authors: Soares Pollyanna Mafra , Soares Mayara Mafra , Lourencetti Mariane Pacheco dos Santos , Ganda Muriell Ribeiro , Souza Mariana Assunção de , Tavares Tatiane Cristina Fernandes , Junior Álvaro Ferreira , Lima Anna Monteiro Correia 
Published: May 2018

Background: The immunoglobulin Y is a principal antibody current in the blood of hens, which are transferred from the maternal blood serum to the egg yolk. The extraction of IgY from the egg yolk apply animal welfare when compared to the extraction of IgG, reducing the number of animals and prevent a bleeding of hens through the extraction of the IgY from eggs, besides that IgY presenting high specificity for antigenic binding. The objective of this study was to produce specific polyclonal IgY antibodies anti-Brucella abortus by immunizing hens with B19 vaccine and evaluate their reactivity through Buffered Acidified Plate Antigen (BAPA), 2-Mercaptoethanol (2-ME) and indirect ELISA diagnostic tests.Materials, Methods & Results: Four 25-week-old White Leghorn hens were immunized, two of them comprising the control group (Group 1) with phosphate-buffered saline (PBS) with adjuvant, and the others two immunized with B19 vaccine (Brucella abortus vaccine strain B19), representing the Group 2. The immunizations occurred six times with a 15-day interval between each. Blood samples were taken biweekly (seven times); and daily, the eggs were collected for 13 weeks, the first collection of blood and eggs, performed one week before the first immunization of each group. The IgY was purified from egg yolk, using the method of dilution in acid water and precipitation with ammonium sulfate for delipidation. BAPA, 2-ME and ELISA tests performed to verify the specificity of IgY confirmed the reactivity of polyclonal antibodies specific to the antigen used both in blood serum samples and in the purified egg yolks. The hens from the control group did not present reactivity in the diagnostic tests used, which was already expected, since no antigen was used in any of their immunizations. Hens immunized with the Brucella abortus B19 vaccine produced detectable reactive antibodies in the three tests used on blood serum and IgY samples extracted from the egg yolk. In Group 2 (vaccine B19), blood serum samples started to react one week after the first inoculation, and the IgY samples extracted from the egg yolk were reagent two weeks after serum IgY appear reactivity, showing the transfer of specific antibodies to the egg yolk, was late.Discussion: Although the transfer of serum Igy to egg yolk was late when compared to others authors which found that the transovarian passage of immunoglobulin Y occurred in approximately three to six days after IgY being detected in blood serum, the results of this study showed the occurrence of the transfer of blood serum IgY anti-Brucella abortus to egg yolk of hens immunized with B19 vaccine, the same found by others researches found the same results with others antigens. Thus, it can be concluded that immunoglobulins Y produced in this study can be used as specific antibodies in diagnostic tests for the detection of the Brucella abortus antigen, in addition, this process guarantees the welfare of the animal, since it avoids bleeding and it is possible to obtain high concentrations of antibodies directly from the hen egg, which is a great advantage, because IgY can be easily isolated from the egg yolk by the precipitation technique discarding the need of invasive and painful procedures that involve bloody interventions to obtain the serum antibodies like occur in mammals for extraction of IgG.