Ciência Animal Brasileira (Oct 2008)
EXPERIMENTAL INFECTION BY Trypanosoma vivax IN GOATS INFECÇÃO EXPERIMENTAL EM CAPRINOS COM Trypanosoma vivax
Abstract
<span><p align="justify">Four goats were infected intravenously with 1.0 mL of cattle blood containing about 1.25 x 10<sup>5</sup> <em>Trypanosoma vivax</em> derived from spontaneous outbreak in cattle at Catolé do Rocha city, Paraíba, Brazil. Other four goats were used as controls. Parasitemia and body temperature were determined daily for 40 days. Animals were weighted each 7 days, and blood samples for blood cells counts were collected each 5 days. It was obtained a sample of liquor from each animal before death; cerebrospinal fluid samples were submitted to biochemical and cytological evaluations, density determination and parasite detection. A positive correlation was found between body temperature and parasitemia in infected animals. These animals presented anemia, leukopenia, hypoglycemia, decreased serum levels of total proteins and cholesterol, and nervous symptoms. Examination of cerebrospinal fluid resulted in decrease of glucose levels and increase in lactate dehydrogenase, cell counts and presence of the parasite. At necropsy it was found pale carcass, generalized infartation of lymphonodes, pulmonary edema, and liquid accumulation of pericardium. Histological changes were characterized by interstitial pneumonia, miocarditis, cardiac fibrosis, meningitis, and encephalitis. All observed changes confirm patogenicity of <em>T. vivax</em>.</p><span><p align="justify">KEY WORDS: Experimental infection, trypanosomiasis, patogenicity.</p></span></span> <span><p align="justify">Quatro caprinos foram infectados experimentalmente por via intravenosa com 1,0 ml de sangue contendo aproximadamente 1,25 x 10<sup>5</sup> tripanossomas/ml, utilizando-se um isolado de <em>Trypanosoma vivax</em> de bovinos infectados naturalmente no município de Catolé do Rocha, Paraíba. A parasitemia e a temperatura foram determinadas diariamente durante quarenta dias. A cada cinco dias realizaram-se coletas de sangue para hemograma e análise bioquímica sérica. Antes do óbito de cada animal procedeu-se à coleta de líquido cefalorraquidiano para avaliação bioquímica e pesquisa da presença do parasita. Nos animais do grupo infectado registrou-se correlação positiva entre a temperatura retal e a parasitemia. Os animais apresentaram anemia, leucopenia, hipoglicemia, redução das proteínas totais e colesterol, além de sintomatologia nervosa. A avaliação do líquor revelou diminuição dos níveis de glicose, aumento da enzima lactato desidrogenase, aumento da celularidade e presença do tripanossomo. As lesões macroscópicas encontradas à necropsia foram palidez da carcaça, aumento generalizado dos linfonodos, edema pulmonar e acúmulo de líquido no saco pericárdico. As lesões histológicas foram pneumonia intersticial, edema pulmonar, miocardite e fibrose cardíaca, meningite e encefalite. As alterações clínicas, hematológicas, bioquímicas e anátomo-patológicas confirmaram a patogenicidade da cepa de<em> T. vivax.</em></p><em><span><p align="justify">PALAVRAS-CHAVES: Infecção experimental, tripanosomose, patogenicidade.</p></span></em></span>
