Valeria Bentes Ferreira
Epidemiologia da Tuberculose Bovina no Agreste Alagoano
Resumo
Bovine tuberculosis (TB) is an infectious disease mainly caused by the bacterium Mycobacterium bovis, which usually results in the formation of nodular granulomas and affects different hosts, including domestic animals, wildlife, and humans. We aimed to evaluate the occurrence of TB in slaughtered cattle in Alagoas and to identify the etiological agent through molecular analysis. Samples were collected from twenty cattle, averaging 24-36 months old, with carcass condemnation characteristics based on the Industrial and Sanitary Inspection Regulations of Animal-Origin Products - RIISPOA, from a slaughterhouse in Arapiraca- AL. The samples were processed in three parts: for histopathological analysis, for mycobacteria isolation by culture, and for identification through molecular analysis (PCR) directly from the tissue. The condemned animals came from nine municipalities in Alagoas, being Arapiraca, Atalaia, Batalha, Cacimbinhas, Girau do Ponciano, Major Izidoro, Minador do Negrão, Monteirópolis and Santana do Ipanema, and Nossa Senhora de Lourdes, Sergipe. In total, 107 samples were obtained, with the highest involvement in carcass/rib (21, 19.63%) and lung (20, 18.69%), followed by spleen (15, 14.02%) and lymph node (15, 14.02%), liver (14, 13.08%), head (10, 9.35%) and intestine (10, 9.35%), abscess (1, 0.93%), and pericardium (1, 0.93%). The lung samples were initially analyzed using an automated molecular test (GeneXpert MTB/RIF Ultra), and all samples tested positive. After cultivation on pyruvate-enriched Löwenstein-Jensen agar, we obtained purified colonies from 16 (80%) lung samples. The results highlight the presence of cattle with TB in Alagoas, reinforcing the importance of RIISPOA, since all condemned carcasses were positive in the molecular analysis. Additionally, this study presents a survey of the organs and tissues most affected by bovine TB, suggesting targets, beyond the lungs, for testing to identify the causative agent. Continuous TB surveillance is essential to minimize the spread of the infection, aiming to reduce its impact on both public health and livestock production, and contributing as an effective measure for prevention, control, and possible eradication of bovine TB.