PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Martins C.F., Madruga C.R., Koller W.W., Araújo F.R., Soares C.O., Kessler R.H., Melo E.S.P., Rios L.R., Almeida R.C.F., Lima Jr M.S.C., Barros A.T.M. & Marques L.C. 2008. Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil. Pesquisa Veterinária Brasileira 28(1):51-56. Departamento de Clínica Médica da Universidade para o Desenvolvimento do Estado e da Região do Pantanal, Rua Ceará 333, Bairro Miguel Couto, Cx. Postal 2153, Campo Grande, MS 79003-010, Brazil. E-mail: claudio.madruga@pq.cnpq.br Trypanosoma vivax outbreaks in beef cattle in the Pantanal region of Mato Grosso do Sul state, Brazil, causes relevant economical impact due to weight loss, abortion and mortality. Cattle moved from the Pantanal to adjacent areas of this ecosystem for breeding and fattening is a common feature. Therefore an epidemiological study on breeding cows in the transition area between Pantanal lowland and adjacent highlands of Mato Grosso do Sul was performed to determine the T. vivax infection dynamics and outbreak risk. Three experimental groups were formed: Group 1 consisted of cows parasitologically negative by the Woo test and in the enzyme-linked immunosorbent assay for T. vivax antibody detection (Tv-ELISA-Ab); Group 2 parasitologically negative and positive in the Tv-ELISA-Ab; and in Group 3 cows were parasitologically positive and with positive reactions in the Tv-ELISA-Ab. During 24 months, the cows’ dislodgment between the above established groups was monitored by Woo test and Tv-ELISA-Ab exams. The tabanid population was also monitored and the highest number occurred during the rainy season. Although parasitemias were detected only in the first four samplings of the experimental period, the cows could be considered as trypanotolerant, because no clinical signs were observed. Despite the higher T. vivax incidence during the dry season, no disease symptoms were seen. Even though T. vivax epidemiological situation in the herd was characterized as endemic with seasonal variation, the probability of outbreaks was null within the conditions of the study.

• Trypanosoma (Dutonella) vivax cattle tabanids infection dynamics epidemiology

Abstract in Portuguese:

ABSTRACT.- Martins C.F., Madruga C.R., Koller W.W., Araújo F.R., Soares C.O., Kessler R.H., Melo E.S.P., Rios L.R., Almeida R.C.F., Lima Jr M.S.C., Barros A.T.M. & Marques L.C. 2008. Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil. Pesquisa Veterinária Brasileira 28(1):51-56. Departamento de Clínica Médica da Universidade para o Desenvolvimento do Estado e da Região do Pantanal, Rua Ceará 333, Bairro Miguel Couto, Cx. Postal 2153, Campo Grande, MS 79003-010, Brazil. E-mail: claudio.madruga@pq.cnpq.br Trypanosoma vivax outbreaks in beef cattle in the Pantanal region of Mato Grosso do Sul state, Brazil, causes relevant economical impact due to weight loss, abortion and mortality. Cattle moved from the Pantanal to adjacent areas of this ecosystem for breeding and fattening is a common feature. Therefore an epidemiological study on breeding cows in the transition area between Pantanal lowland and adjacent highlands of Mato Grosso do Sul was performed to determine the T. vivax infection dynamics and outbreak risk. Three experimental groups were formed: Group 1 consisted of cows parasitologically negative by the Woo test and in the enzyme-linked immunosorbent assay for T. vivax antibody detection (Tv-ELISA-Ab); Group 2 parasitologically negative and positive in the Tv-ELISA-Ab; and in Group 3 cows were parasitologically positive and with positive reactions in the Tv-ELISA-Ab. During 24 months, the cows’ dislodgment between the above established groups was monitored by Woo test and Tv-ELISA-Ab exams. The tabanid population was also monitored and the highest number occurred during the rainy season. Although parasitemias were detected only in the first four samplings of the experimental period, the cows could be considered as trypanotolerant, because no clinical signs were observed. Despite the higher T. vivax incidence during the dry season, no disease symptoms were seen. Even though T. vivax epidemiological situation in the herd was characterized as endemic with seasonal variation, the probability of outbreaks was null within the conditions of the study.

Abstract in English:

ABSTRACT.- Melo E.S.P., Araújo F.R., Ramos C.A.N., Soares C.O., Rosinha G.M.S., Elisei C. & Madruga C.R. 2007. [ELISA based on recombinant truncated MSP5 for detection of antibodies against Anaplasma marginale in cattle.] ELISA com MSP5 recombinante truncada para detecção de anticorpos contra Anaplasma marginale em bovinos. Pesquisa Veterinária Brasileira 27(7):301-306. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br The objective of this study was the production and solubilization of recombinant truncated MSP5 of Anaplasma marginale and the evaluation of its performance in an enzyme-linked immunosorbent assay (ELISA), to detect antibodies against the rickettsia in cattle. The fragment of msp5 gene, except the hydrophobic N-terminal region, was amplified by PCR, cloned in pTrcHis-TOPO plasmid and expressed in Escherichia coli. Solubilization of the recombinant protein was evaluated in different pHs and concentrations of urea. The sensibility and specificity of the assay were evaluated with 66 sera from cattle experimentally-infected and 96 sera from cattle free of A. marginale defined by polymerase chain reaction for msp5 gene. Serum samples from 1,666 cattle from Brazil - states of Rio Grande do Sul (73), Mato Grosso do Sul (91), Pernambuco (86), Bahia (314) and Minas Gerais (267), Uruguay (32) and Costa Rica (803), were tested by ELISAs with recombinant truncated MSP5 and with recombinant MSP1a, and the agreement between both ELISAs was calculated. ELISA with recombinant truncated MSP5 protein detected infected animals with sensibility of 96.97% and specificity of 100%. In cattle experimentally-infected, the ELISA detected antibodies from the 12th day post-infection (DPI) to the end of the experiment, at the 37th DPI. The agreement between the ELISAs with truncated MSP5 and MSP1a antigens was 95.67%, with a kappa index of 0.81. Disagreement results showed significative difference (p <0.001). Antibodies for A. marginale were detected in animals of the all the region analyzed. The ELISA with recombinant truncated MSP5 showed a good performance in ELISA for detention of antibodies against A. marginale, with high sensitivity and specificity, representing an important tool for the diagnosis of anaplasmose bovine in epidemiological studies.

• Anaplasma marginale ELISA MSP5 solubilization recombinant protein

Abstract in Portuguese:

ABSTRACT.- Melo E.S.P., Araújo F.R., Ramos C.A.N., Soares C.O., Rosinha G.M.S., Elisei C. & Madruga C.R. 2007. [ELISA based on recombinant truncated MSP5 for detection of antibodies against Anaplasma marginale in cattle.] ELISA com MSP5 recombinante truncada para detecção de anticorpos contra Anaplasma marginale em bovinos. Pesquisa Veterinária Brasileira 27(7):301-306. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br The objective of this study was the production and solubilization of recombinant truncated MSP5 of Anaplasma marginale and the evaluation of its performance in an enzyme-linked immunosorbent assay (ELISA), to detect antibodies against the rickettsia in cattle. The fragment of msp5 gene, except the hydrophobic N-terminal region, was amplified by PCR, cloned in pTrcHis-TOPO plasmid and expressed in Escherichia coli. Solubilization of the recombinant protein was evaluated in different pHs and concentrations of urea. The sensibility and specificity of the assay were evaluated with 66 sera from cattle experimentally-infected and 96 sera from cattle free of A. marginale defined by polymerase chain reaction for msp5 gene. Serum samples from 1,666 cattle from Brazil - states of Rio Grande do Sul (73), Mato Grosso do Sul (91), Pernambuco (86), Bahia (314) and Minas Gerais (267), Uruguay (32) and Costa Rica (803), were tested by ELISAs with recombinant truncated MSP5 and with recombinant MSP1a, and the agreement between both ELISAs was calculated. ELISA with recombinant truncated MSP5 protein detected infected animals with sensibility of 96.97% and specificity of 100%. In cattle experimentally-infected, the ELISA detected antibodies from the 12th day post-infection (DPI) to the end of the experiment, at the 37th DPI. The agreement between the ELISAs with truncated MSP5 and MSP1a antigens was 95.67%, with a kappa index of 0.81. Disagreement results showed significative difference (p <0.001). Antibodies for A. marginale were detected in animals of the all the region analyzed. The ELISA with recombinant truncated MSP5 showed a good performance in ELISA for detention of antibodies against A. marginale, with high sensitivity and specificity, representing an important tool for the diagnosis of anaplasmose bovine in epidemiological studies.

Abstract in English:

ABSTRACT.- Melo V.S.P., Passos L.M.F, Facuri-Filho E.J., Saturnino H.M. & Ribeiro M.F.B. 2001. Natural infection of calves by Anaplasma marginale in dairy herds of the Metalúrgica Region, Minas Gerais. [Infecção natural por Anaplasma marginale em bezerras de fazendas leiteiras da região Metalúrgica de Minas Gerais] Pesquisa Veterinária Brasileira 21(4):146-150. Depto Parasitologia, Universidade Federal de Minas Gerais, Cx. Postal 486, Belo Horizonte, MG 31270-910, Brazil. The dynamic of natural infections by Anaplasma marginale in calves was evaluated during a period of one year on two farms located in the Metalúrgica Region, State of Minas Gerais, Brazil. Blood samples were collected weekly for rickettsemia and packed cell volume (PCV) determination. The animals born from March to July suffered the infection in October and November, independently of their age, whilst calves born from September to December acquired the infection during the first days of life. These animals presented patent rickettsemia from 30 days of life. During the patent period PCV decreased after one week of infection, ranging from 20 to 23%. It was concluded, that in the region studied, the transmission of A. marginale is influenced by climatic conditions, and that calves born during the dry season are more likely to acquire the infection when they are exposed to high transmission leveis during the subsequent raining season.

• Anaplasma marginale anaplasmosis cattle epidemiology anaplasmose bovinos epidemiologia.

Abstract in Portuguese:

RESUMO.- Melo V.S.P., Passos L.M.F, Facuri-Filho E.J., Saturnino H.M. & Ribeiro M.F.B. 2001. Natural infection of calves by Anaplasma marginale in dairy herds of the Metalúrgica Region, Minas Gerais. [Infecção natural por Anaplasma marginale em bezerras de fazendas leiteiras da região Metalúrgica de Minas Gerais] Pesquisa Veterinária Brasileira 21(4):146-150. Depto Parasitologia, Universidade Federal de Minas Gerais, Cx. Postal 486, Belo Horizonte, MG 31270-910, Brazil. Realizou-se um estudo da dinâmica de infecções naturais por Anaplasma marginale, durante o período de um ano, em duas propriedades localizadas na Região Metalúrgica do Estado de Minas Gerais. Foram realizados esfregaços sangüíneos e determinação do volume globular (VG). Os animais que nasceram no período de março a julho sofreram a infecção em outubro e novembro, independentemente da idade, enquanto os que nasceram no período de setembro a dezembro adquiriram a infecção nos primeiros dias de vida, com parasitemia patente a partir de 30 dias de idade. Durante o período patente, o VG reduziu na primeira semana de infecção, variando entre 20 a 23%. Concluiu-se que a ocorrência da primo-infecção sofre influência das estações do ano e que bezerros nascidos na estação seca apresentam maior risco de infecção, quando expostos às condições de elevada transmissão durante a estação chuvosa subseqüente.