Bovine tuberculosis in the north of brazil

Bovine tuberculosis (BTB) is an infectious disease worldwide distributed, caused by Mycobacterium bovis, which affects cattle and other animals, including humans. In Brazil, BTB is endemic and causes economic losses by reducing the productivity of livestock and loss of carcasses in the slaughterhouses. Molecular epidemiology has been used as a tool for the investigation of M. bovis transmission and dynamic of this disease. Herein, we studied 99 samples of lymph nodes obtained from animals (with or without suggestive lesion) slaughtered in the Northern region of Brazil. We evaluated the presence of M. bovis through microscopy techniques, culture in Stonebrinck medium and molecular identification using polymerase chain reaction (PCR) testing. In addition, two genotyping methods (Spoligotyping and MIRU-VNTR) were used in order to identify the genotypic profile of these strains. Out of 99 retropharyngeal lymph nodes collected, only ten clinical samples were amplified using PCR technique, and were considered positive to M. bovis. These samples were further investigated using molecular analysis of the combination of spoligotyping and MIRU-VNTR, and it was possible to identify eight different patterns. Only one spoligotype, majority among the samples tested (40%), had already been identified in the database (SIT523). Through the epidemiological identification of these strains, it is possible to investigate the dynamic transmission of the disease, which is an essential part of more specific and effective control of diseases such as tuberculosis.