Caracterização histológica e imuno-histoquímica das lesões de tuberculose em bovinos e de linfadenite granulomatosa em suínos

Abstract

Mycobacterium sp. induces granulomatous inflammation in different animal species. Mycobacterium bovis and the Mycobacterium avium complex are important cattle and swine pathogens that can also infect humans, especially those immunosuppressed. Losses in production, commercial barriers and carcasses condemnations in slaughtering are related to this infection, which implies in large economic losses. It was carried out a study on bovine tuberculosis lesions and granulomatous lymphadenitis in pigs, diagnosed by the Setor de Patologia Veterinária from the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, between January 2007 and December 2011. Data concerning breed, sex, age and clinical history were retrieved from the files and analyzed. Histological features of the lesions in lymph nodes and lungs were evaluated in Hematoxylin-Eosin staining. Multinucleated giant cells were predominant in bovine tuberculosis lesions and epithelioid macrophages were abundant in swine. Ziehl-Neelsen and Masson's trichrome techniques were used respectively to demonstrate the alcohol-acid resistant bacillus and fibrous connective tissue in the lesions. The immunohistochemistry technique was performed to characterize the lymphocytic infiltrate. Anti-CD3 antibodies were utilized to immunolabeling lymphocytes T; and anti-CD79αcy to lymphocytes B. Lymphocytes T were predominant in both species lesions; confirmed statistically by paired t test, which showed significantly differ means of T and B lymphocytes, with t=5,501 (p<0.001) for the bovines tuberculosis lesions, and t=5.826 (p<0.001), for the cases of pigs lymphadenitis. In addition, macrophages were immunolabeled by antibody anti-CD68 to bovine, and lysozyme to swine; and polyclonal anti-Mycobacterium tuberculosis antibody were used successfully to detect Mycobacterium sp. in bovine and swine lesions, apart from in the swine samples there was also anti-Mycobacterium avium immunolabelling.