Padronização de testes e interferência da vacinação contra leptospirose no diagnóstico em brucelose bovina

Abstract

This dissertation was divided in two studies. The first study evaluated the standardization two indirect enzyme-linked immunosorbent assay (iELISA) for the diagnosis of bovine brucellosis using antigen as inactivated strain B1119-3 and lipopolysaccharide (LPS) from Brucella abortus. 92 serum samples, 46 positive and 46 negative were used by brucellosis tests. The iELISA/B1119-3 had a sensitivity of 100% and specificity of 95.6%. The iELISA/LPS sensitivity was 97.8% and specificity of 91.3%. When compared 2ME tests with iELISA/B1119-3 and iELISA/LPS as observed a concordance of 97.83% and 94.57% respectively. Both iELISA tests were efficient in the diagnosis of bovine brucellosis. The second study aimed to verify if cattle vaccinated against leptospirosis can react in diagnostic tests for brucellosis. Sixty cattle were divided in five groups, with 12 animals each. Four groups received different vaccines for leptospirosis, and a control group received only saline. Serum samples were collected on days zero, seven, 14, 21, 28, 35, 42.49, 56, 96 and 126. The serum samples were tested for brucellosis and leptospirosis. Twenty cattle were reactive in the Rose Bengal Test (RBT), at least once, in which two animals responded three times, and two animals responded twice, a total of 26 positive samples. Seven were confirmed, one in 2-Mercaptoethanol (2ME), two in Fluorescence Polarization Assay (FPA) and six in the iELISA, in which two animals reacted in two confirmatory tests simultaneously. Only in Complement Fixation (CF) test there was none positive animal. Only five animals were confirmed positive. Thus, these results confirm that cattle vaccinated against leptospirosis can react in tests for brucellosis.