Three ELISA (Enzime-linked immunosorbent assay) tests based on purified capsular antigen from serotypes 3, 5 and 7 of Actinobacillus pleuropneumoniae, prevalent in Brazil, were standardized. Serum samples, collected from piglets inoculated with these three serotypes, were used to standardize the test. In order to study the dynamic of antibody synthesis, weekly blood samples were collected from these piglets. A pool of 130 sera obtained from Actinobacillus pleuropneumoniae -free pigs was used as negative control for the tests. The antigens were also tested with serum samples from animals infected with other respiratory infectious agents and vaccinated against athrofic rinitis. The antigens were efficient in detecting animals infected with App. Optical densities above the average of the negative control sera plus four standard deviation were detected. ELISA tests to serotypes 3, 5 and 7 showed specificity of 100% and sensibility of 92, 88 and 90%, respectively. No cross reaction with other serotypes or with sera of animals inoculated with other respiratory pathogens was observed. The results were analyzed using the Statistical Analysis System program. Antigens tested were adequate for serotyping animals previously screened through a polyvalent LPS-LC ELISA test.
Actinobacillus pleuropneumoniae; ELISA; capsular antigen
