PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

• rypanosomosis small ruminant PCR anatomopathology testicular degene-ration epididymitis extravascular foci

Abstract in Portuguese:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

Abstract in English:

ABSTRACT.- Batista J.S., Bezerra F.S.B., Lira R.A., Carvalho J.R.G., Rosado Neto A.M., Petri A.A. & Teixeira M.M.G. 2008. [Clinical, epidemiological and pathological signs of natural infection in cattle by Trypanosoma vivax in Paraíba, Brazil.] Aspectos clínicos, epidemiológicos e patológicos da infecção natural em bovinos por Trypanosoma vivax na Paraíba. Pesquisa Veterinária Brasileira 28(1):63-69. Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Caixa Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Two outbreaks of trypanosomiasis by Trypanosoma vivax, reported in cattle, occurred on two farms located in the state of Paraíba, northeastern Brazil. The epidemiology, clinical signs and pathology of the disease were studied from May 2005 to November 2006. T. vivax was identified morphologically and by polymerase chain reaction test (PCR). The affected cattle presented anorexia, depression, fever, anemia, weight loss, reduction in milk production, transitory blindness, abortion and some nervous signs as nystagmus, tetany and bruxism. All cattle that presented nervous signs died. Necropsy findings were enlarged lymph and spleen, serous atrophy of the fat depots, proeminence of the splenic white pulp, hydropericardium and pericardial petechiae and ecchymoses on the epicardium. Histologically there was meningoencephalitis. The treatment of the clinical cases with diminazena aceturate was efficient with clearance of the parasite from the blood or disappearance of clinical signs in up to 2 months after the beginning of the outbreak on the two farms studied. The epidemiologic factors favoring the occurrence of the outbreak were the abundance of mechanical vectors, as tabanids and Stomoxys sp., and the introduction into the herd of cattle from farms where the disease occurred. It is suggested that the semiarid of the Brazilian Northeast is an enzootic instability region for trypanosomiasis due to its prolonged periods of drought and high temperatures, constituting during most part of the year an unfavorable environment for the development of vectors.

• Trypanosoma vivax trypanosomiasis cattle outbreak Brazilian Northeast semi-arid

Abstract in Portuguese:

ABSTRACT.- Batista J.S., Bezerra F.S.B., Lira R.A., Carvalho J.R.G., Rosado Neto A.M., Petri A.A. & Teixeira M.M.G. 2008. [Clinical, epidemiological and pathological signs of natural infection in cattle by Trypanosoma vivax in Paraíba, Brazil.] Aspectos clínicos, epidemiológicos e patológicos da infecção natural em bovinos por Trypanosoma vivax na Paraíba. Pesquisa Veterinária Brasileira 28(1):63-69. Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Caixa Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Two outbreaks of trypanosomiasis by Trypanosoma vivax, reported in cattle, occurred on two farms located in the state of Paraíba, northeastern Brazil. The epidemiology, clinical signs and pathology of the disease were studied from May 2005 to November 2006. T. vivax was identified morphologically and by polymerase chain reaction test (PCR). The affected cattle presented anorexia, depression, fever, anemia, weight loss, reduction in milk production, transitory blindness, abortion and some nervous signs as nystagmus, tetany and bruxism. All cattle that presented nervous signs died. Necropsy findings were enlarged lymph and spleen, serous atrophy of the fat depots, proeminence of the splenic white pulp, hydropericardium and pericardial petechiae and ecchymoses on the epicardium. Histologically there was meningoencephalitis. The treatment of the clinical cases with diminazena aceturate was efficient with clearance of the parasite from the blood or disappearance of clinical signs in up to 2 months after the beginning of the outbreak on the two farms studied. The epidemiologic factors favoring the occurrence of the outbreak were the abundance of mechanical vectors, as tabanids and Stomoxys sp., and the introduction into the herd of cattle from farms where the disease occurred. It is suggested that the semiarid of the Brazilian Northeast is an enzootic instability region for trypanosomiasis due to its prolonged periods of drought and high temperatures, constituting during most part of the year an unfavorable environment for the development of vectors.

Abstract in English:

Batista J.S., Riet-Correa F., Barbosa R.C. & Guerra J.L. 2006. [Experimental infection by Trypanosoma vivax in sheep.] Infecção experimental por Trypanosoma vivax em ovinos. Pesquisa Veterinária Brasileira 26(1):31-37. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br This paper has the objective to report clinical signs, hematologic changes, and macroscopic and microscopic alterations in sheep infected experimentally with Trypanosoma vivax, isolated from an outbreak in cattle in the semiarid region of the state of Paraíba, northeastern Brazil. Four Santa Inês sheep were inoculated intravenously with 1ml of blood containing 1.85x105 trypomastigotes. Other 4 sheep were used as control. The presence of trypanosomes in the blood and the temperature were recorded daily during the first 30 days and fortnightly from day 31 to day 90 after infection. Also fortnightly, the sheep were weighed and blood samples were obtained for hematological analysis. One inoculated sheep died 75 days after inoculation. The other 3 inoculated and the 4 control sheep were killed 90 days after the beginning of the experiment. T. vivax was observed constantly in the blood of the inoculated sheep from 4-15 days after inoculation. From day 16 to day 30 the parasitemia was lower and irregular. No trypanosomes were observed in the blood after 30 days of infection. A positive linear correlation [Y=0.027x + 38.515, R2=0.944 (P<0.05)] was found between the number of trypanosomes in the blood and body temperature. Significant differences were observed in body weight between inoculated and non-inoculated sheep from day 30 to day 90 after the experiment. From day 30 to day 90 after inoculation trypanosomes were absent or only in low numbers in the blood, and the animals showed anemia and leucopenia. Gross alterations were pale carcasses, enlarged lymph nodes and spleen, and augmented liquid in the peritoneal and pericardiac cavities. Multifocal lymphocytic myocarditis was observed histologically. It is concluded that the isolate is pathogenic to sheep. It is suggested that the semiarid region, where the outbreak occurred, is non-endemic (marginal) for trypanosomosis, and that the disease may occur if the parasite is introduced through vectors.

• Experimental infection Trypanosoma vivax sheep semiarid.

Abstract in Portuguese:

Batista J.S., Riet-Correa F., Barbosa R.C. & Guerra J.L. 2006. [Experimental infection by Trypanosoma vivax in sheep.] Infecção experimental por Trypanosoma vivax em ovinos. Pesquisa Veterinária Brasileira 26(1):31-37. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br This paper has the objective to report clinical signs, hematologic changes, and macroscopic and microscopic alterations in sheep infected experimentally with Trypanosoma vivax, isolated from an outbreak in cattle in the semiarid region of the state of Paraíba, northeastern Brazil. Four Santa Inês sheep were inoculated intravenously with 1ml of blood containing 1.85x105 trypomastigotes. Other 4 sheep were used as control. The presence of trypanosomes in the blood and the temperature were recorded daily during the first 30 days and fortnightly from day 31 to day 90 after infection. Also fortnightly, the sheep were weighed and blood samples were obtained for hematological analysis. One inoculated sheep died 75 days after inoculation. The other 3 inoculated and the 4 control sheep were killed 90 days after the beginning of the experiment. T. vivax was observed constantly in the blood of the inoculated sheep from 4-15 days after inoculation. From day 16 to day 30 the parasitemia was lower and irregular. No trypanosomes were observed in the blood after 30 days of infection. A positive linear correlation [Y=0.027x + 38.515, R2=0.944 (P<0.05)] was found between the number of trypanosomes in the blood and body temperature. Significant differences were observed in body weight between inoculated and non-inoculated sheep from day 30 to day 90 after the experiment. From day 30 to day 90 after inoculation trypanosomes were absent or only in low numbers in the blood, and the animals showed anemia and leucopenia. Gross alterations were pale carcasses, enlarged lymph nodes and spleen, and augmented liquid in the peritoneal and pericardiac cavities. Multifocal lymphocytic myocarditis was observed histologically. It is concluded that the isolate is pathogenic to sheep. It is suggested that the semiarid region, where the outbreak occurred, is non-endemic (marginal) for trypanosomosis, and that the disease may occur if the parasite is introduced through vectors.