Data/hora: 16/06/2024 06:00:38

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 11/09/1997
Data da última atualização: | 11/09/1997
Autoria: | SILVA, R. A. M. S.; HERRERA, H. M.; DAVILA, A. M. R.; RAMIREZ, L.; PEREIRA, M. E. B.
Afiliação: | EMBRAPA. Centro de Pesquisa Agropecuaria do Pantanal (Corumba, MS); UFMS. Centro Universitario de Corumba (Corumba, MS).
Título: | Pathogenesis of Trypanosoma evansi infection in dogs and horses: light microscopic studies on erythrocyte pathologic changes.
Ano de publicação: | 1995
Fonte/Imprenta: | Memorias do Instituto Oswaldo Cruz, Rio de Janeiro, v.90, p.299, 1995. Suplemento I.
Idioma: | Inglês
Conteúdo: | Trypanosomosis continue to be a problem to human beings and domestic animals in Africa and South America. Effort at control have been only minimally successful, and several areas of the complex disease process remain unclear. Anemia is one of the most consistent findings in trypanosomosis. The nature of the anemia is not completely elucidated and several mechanisms have been proposed including increased red cell destruction, extravascular and intravascular hemolysis by immune (trypanosome antigen/antibody complex and antierythrocyte antibodies), hemolysins, nonspecific phagocytosis activation, direct traumatic effect of trypanosomes, microangiopathy associated with disseminated intravascular coagulation (DIC), splenic phagocytosis and splenic pooling, increased plasma volume, noncompensatory and/or decreased erythropoiesis and anemia of chronic disorders. In the present study, light microscopy were used to investigate aspects of erythrocite pathologic changes in dogs and horses naturally infected by T. evansi. Thin blood films stained with May Gruwald-Giemsa from ten horses and four dogs naturally infected with T. evansi were examined for morphologic abnormalities of erytrocytes. Several erytrocytes abnormalities were observed in the blood of infected dogs and horses. These included the appearance of microspherocytes, acanthocytes, dacrocytes, codocytes, vacuolated, and sometimes bizarre shapes. Polychromasia and poikilocytosis were present in both dogs and horse erythrocytes. Adhesion of erythrocytes to trypanosomes in circulanting blood and erythrophagocytosis were also observed. The adhesion phenomenon has also been demonstrated in T. gambiense, T. rhodesiense, T. brucei, T. congolense and T. lewisi. The adhesion may damage the erythrocyte through alterations of membrane and to predispose to destruction of the affected red cell. Erythrophagocytosis demonstrated in our study with light microscopy has also been observed in various infections by other trypanosome species. We conclude that erythrocyte abnormalities, trypanosome adhesion to red cells and erythrophagocytosis are important cause of anemia in trypanosomosis due to T. evansi in dogs and horses.
Palavras-Chave: | Cachorro; Dog; Horse.
Thesagro: | Cavalo.
Thesaurus Nal: | Trypanosoma evansi.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (34853-1) - UPC - AP - -- - AP614.405 -  - 614.405 - DIS