Evaluation of technical, immunodiffusion agar gel, enzyme-linked immunosorbent assay and polymerase chain reaction in the diagnosis of ovine brucellosis

ABSTRACT Brucellosis in sheep has received a major focus, since it is a disease that affects the reproductive system of animals, causing serious impairment in the productive sector. Thus, three methods for the diagnosis of ovine brucellosis were evaluated as goal, the indirect Linked Immunosorbent Assay (ELISAi) test, the Immunodiffusion Agar Gel (AGID) technique and the Polymerase Chain Reaction (PCR). Therefore, we used 211 sheep blood samples from properties of nine municipalities of the homogeneous micro-region of Teresina, Piaui. The 211 blood samples were subjected to serologic testing and PCR to detect anti-B. ovis antibodies, and Brucella ovis DNA, respectively. Positive results in serological tests were obtained, 36 (17%) positive in the AGID test and seven (3.3%) positive to the ELISAi test, however, there were no positive results in the PCR technique. Of the diagnostic methods used in this study, the AGID test was the one that presented the best performance in the detection of reactive animals, when compared to ELISAi and PCR in blood samples and, the percentage of seropositive animals suggests a wide distribution of Brucella ovis infected sheep in the study region and could cause loss to producers.