Aspectos anatomopatológicos de pneumonias em suínos de terminaçãocausadas pela Pasteurella multocida de alta patogenicidade

• Ano de defesa: 2012
• Autor(a) principal: Eliana Silva Paladino
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Pneumonia; P multocida; Terminação; Suínos; Ciência Animal
• Link de acesso: http://hdl.handle.net/1843/BUBD-8ZZG8X

Swine respiratory diseases are responsible for several direct and indirect losses to swine herds. Pasteurella multocida is a frequent bacterium involved in the Porcine Respiratory Disease Complex (PRDC) in finishing pigs. Historically, P. multocida is known as an opportunist agent, causing secondary bacterial pneumonia in pigs after previousMycoplasma hyopneumoniae and/or viral infections. Nowadays, several studies have been shown the possible ability of this bacterium to cause primary infection, leading to death. The aim of this study was to evaluate the anatomopathology and microbiology of pulmonary lesions of samples obtained from animals with clinical respiratory disease andcompare to pulmonary samples obtained at slaughter. Twenty-five lung samples, from 14 herds with clinical respiratory disease, and 19, collected at slaughter, from other 14 herds, in a total of 44 evaluated lung samples were studied. In all lung samples, bacterial isolation was performed, and only samples with pure P. multocida growth were included in the evaluation. P. multocida isolates were tested for antimicrobial sensitivity to 15 drugs, and lung samples were submitted to gross and microscopic evaluation. Also, co-infections with Influenza type A, porcine Circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae were studied using immunohistochemistry (IHC). The antimicrobial sensitivity evaluation showed higher sensitivity rate to ceftiofur and spectinomycin, and some resistance rate to lincomycin and penicillin. P. multocida isolated from lungs collected at slaughter were more sensitive to amoxicillin than isolated from clinical samples (p<0.05). Pleuritis wasmore often observed in lungs of clinical samples than lungs obtained at slaughter (p<0.05). Moreover, there was a numerical trend that indicated that pericarditis, lymphadenomegaly and cavity exudates occurred more often in clinical samples. By IHC, eight samples were positive to Influenza type A, 11 to M. hyopneumoniae, 12 had M. hyopneumoniae and Influenza type A mixed infection, none were positive to PCV2, and 13 were negative to all three of these agents and only tested positive to P. multocida. In these samples, lesions such as pleuritis, pericarditis and lymphadenomegaly were observed only in clinical samples. This finding suggests the ability of these P. multocida isolates to cause primary infection however, it was not possible to determine in this study specific virulence markers.