Occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in pigs in the State of Pará, Brazil / Ocorrência de anticorpos contra Toxoplasma gondii e Neospora caninum em suínos no estado do Pará, Brasil

Abstract We investigated the occurrence of Toxoplasma gondii and Neospora caninum antibodies in pigs raised in the Northeast of Pará, Brazil. At Study I, convenience sampled 151 pigs at two slaughterhouses, with and without state inspection; and Study II, which assessed 159 pigs with probabilistic sampling from nine pig farms. Serological analysis was performed using indirect fluorescent antibody test for T. gondii and N. caninum with a cutoff of 64 and 50, respectively. Overall, 6.77% pigs were seropositive for T. gondii and 5.16% for N. caninum. In Study I, pigs slaughtered with and without state inspection presented similar occurrence for both coccidia (p>0.05). Study II found an association between N. caninum seropositivity and sludge discarded into the soil, feeding pigs with animal-based protein, subsistence system, and absence of nipple drinkers. No association was found for T. gondii. Pigs from Pará are a potential source of T. gondii infection to humans. To our best knowledge, this is the first study to report anti-N. caninum antibodies in the serum of pigs in Pará State, Brazilian Amazon.

Resumo Foi investigada a ocorrência de anticorpos contra Toxoplasma gondii e Neospora caninum em suínos criados no nordeste do Pará, Brasil. No Estudo I, foram amostrados 151 porcos em dois matadouros, com e sem inspeção estadual. O Estudo II avaliou 159 suínos com amostragem probabilística de nove granjas de suínos. Para sorologia, utilizou-se o teste de imunofluorescência indireta para T. gondii e N. caninum com ponto de corte de 1:64 e 1:50, respectivamente. No geral, 6,77% dos suínos foram soropositivos para T. gondii e 5,16% para N. caninum. No Estudo I, suínos abatidos em matadouros com e sem inspeção estadual apresentaram ocorrência semelhante para ambos os coccídios (p> 0,05). Os animais amostrados de Belém, Benevides, Marituba, Bujaru, Castanhal e Igarapé-Miri foram positivos para T. gondii, enquanto os soropositivos para N. caninum foram encontrados em Belém, Bujaru, Castanhal e Santo Antônio do Tauá. O Estudo II encontrou associação entre soropositividade de N. caninum e esterco descartado no solo, alimentação dos suínos com proteína de origem animal, criação de subsistência e ausência de bebedores tipo "nipple". Não foi encontrada associação para T. gondii. A carne suína apresenta potencial risco de transmissão de T. gondii para os habitantes da região. De acordo com nosso conhecimento, este é o primeiro relato de anticorpos anti-N. caninum em suínos no estado do Pará, Amazônia brasileira.

Occurrence of Neospora caninum and Toxoplasma gondii antibodies in dogs from rural properties surrounding a biological reserve, Espirito Santo, Brasil / Ocorrência de anticorpos anti-Neospora caninum e Toxoplasma gondii em cães de propriedades rurais do entorno de uma reserva biológica, Espírito Santo, Brazil

Abstract The aim of this study was to determine the presence of antibodies to Neospora caninum and Toxoplasma gondii in serum samples of 187 dogs from 30 rural properties surrounding Córrego do Veado Biological Reserve, Espírito Santo State, Brazil. The Reserve is one of the last lowland Atlantic Forest remnants of the region, surrounded by agriculture farms and cattle pastures. The presence of IgG antibodies was determined by the Indirect Fluorescent Antibody Test for T. gondii (cut-off 1:16) and N. caninum (cut-off 1:50). Positive samples were diluted 2-fold until the last positive dilution. Antibodies to T. gondii were found in 77 (47.05%) dogs and antibodies to N. caninum in 22 dogs (11.76%) and one only dog was positive for both infections. No association between T. gondii and N. caninum infection and sex was observed (p>0.05). Control measures to prevent those infections in dogs that living surrounding the reserve and that had contact with wild animals are important to avoid the introduction of N. caninum in wild animals. This was the first study of frequency of occurrence of T. gondii and N. caninum in dogs from Espírito Santo, Brazil.

Resumo O objetivo deste estudo foi determinar a presença de anticorpos contra Neospora caninum e Toxoplasma gondii em amostras de soro de 187 cães de 30 propriedades rurais do entorno da Reserva Biológica Córrego do Veado, Espírito Santo, Brasil. A Reserva é um dos últimos remanescentes de Mata Atlântica da região, cercada por fazendas com agricultura e pastagens. A presença de anticorpos IgG foi determinada pela reação de imunofluorescência indireta para T. gondii (ponto de corte de 1:16) e para N. caninum (ponto de corte de 1:50). As amostras positivas foram diluídas na base dois e tituladas. Anticorpos para T. gondii foram encontrados em 77 (47,05%) cães e para N. caninum em 22 (11,76%). Um cão foi positivo para ambas as infecções. Não houve associação entre a infecção pelo T. gondii e N. caninum e o sexo (p>0,05). Medidas de controle, para prevenir essas infecções em cães que vivem no entorno da reserva e com possibilidade de contato com animais selvagens, são importantes para evitar a introdução de N. caninum nos animais selvagens. Este foi o primeiro relato da frequência de anticorpos contra estes coccídios em cães do Espírito Santo, Brasil.

Anti-Toxoplasma gondii and anti-Neospora caninum antibodies in capybaras (Hydrochoerus hydrochaeris) from Itu Municipality, São Paulo / Anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em capivaras (Hydrochoerus hydrochaeris) do Município de Itu, São Paulo

Abstract Capybaras (Hydrochoerus hydrochaeris) are the largest rodents found in South America. The aim of the present study was to investigate the occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in 170 free-living capybaras in a residential park area in Itu Municipality, São Paulo State, Brazil. Serum samples were tested by indirect fluorescent antibody test (IFAT) for T. gondii (IFAT ≥ 1:16) and N. caninum (IFAT ≥ 1:50). Among the 170 samples analyzed, 10% (17/170) and 0% (0/170) were seropositive for T. gondii and N. caninum, respectively. This study confirms the widespread presence of T. gondii and reinforces the role of capybaras in the life cycle of this parasite. Capybaras may not be important as intermediate hosts of N. caninum in the studied environment.

Resumo As capivaras (Hydrochoerus hydrochaeris) são os maiores roedores encontrados na América do Sul. O objetivo do presente estudo foi investigar a ocorrência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em 170 capivaras de vida livre, habitando em um condomínio fechado no Município de Itu, Estado de São Paulo, Brasil. Amostras de soro foram testadas por meio da Reação de Imunofluorescência Indireta (RIFI) para T. gondii (RIFI ≥ 1:16) e N. caninum (RIFI ≥ 1:50). Entre as 170 amostras analisadas, 10% (17/170) e 0% (0/170) foram positivas para T. gondii eN. caninum, respectivamente. O presente estudo confirma a ampla distribuição de T. gondii e reforça o papel das capivaras no ciclo biológico desse parasita. Provavelmente, as capivaras não têm um papel importante como hospedeiros intermediários de N. caninum no ambiente estudado.

Prevalence of antibodies against Neospora spp. and Sarcocystis neurona in donkeys from northeastern Brazil / Prevalência de anticorpos contra Neospora spp e Sarcocystis neurona em jumentos do nordeste do Brazil

Abstract Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT results for S. neurona showed a poor concordance (value of Kappa=0.051). This is the first report ofNeospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.

Resumo Sarcocystis neurona e Neospora hughesi são protozoários coccídios que infectam equídeos e são responsáveis por doenças neurológicas nessas espécies. Neste estudo, a soroprevalência de infecção porS. neurona e Neospora spp. foi determinada em amostras de 333 soros de jumentos da Região Nordeste do Brasil. Anticorpos contra Neospora spp. foram detectados em 2% (7 jumentos) dos 333 animais examinados pela reação de imunofluorescência indireta (RIFI), com ponto de corte de 40. Anticorpos contra S. neurona foram detectados em 3% (10 jumentos) das amostras pela RIFI (ponto de corte de 50) e em 21% (69 jumentos) pela técnica de aglutinação direta (SAT - ponto de corte de 50). SAT e RIFI, para diagnóstico de S. neurona, apresentaram uma baixa concordância (Kappa = 0,051). Essa é a primeira observação de anticorpos anti-N. caninum em jumentos brasileiros e a primeira detecção de anticorpos contra S. neurona nessa espécie.

Risk factors for Toxoplasma gondii and Neospora caninum seropositivity in buffaloes in Paraiba State, Brazil / Fatores de risco associados à soropositividade para Toxoplasma gondii e Neospora caninum em búfalos no Estado da Paraíba, Nordeste do Brasil

The aims of this survey were to determine the frequency of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to identify the risk factors associated with seropositivity among buffaloes in the state of Paraíba, Brazil. This survey included 136 buffaloes belonging to 14 herds. To detect anti-T. gondii and anti-N. caninum antibodies, the indirect fluorescent antibody test (IFAT) was used. Among the 136 samples analyzed, 17 (12.5%) were positive for anti-T. gondii antibodies with titers ranging from 64 to 1,024, and 26 (19.1%) for anti-N. caninum with titers from 200 to 1,600. Animals seropositive for both T. gondii and N. caninum were found in 10 of the 14 herds (71.4%). Semi-intensive management systems (odds ratio = 2.99) and presence of pigs (odds ratio = 4.33) were identified as risk factors for T. gondii and N. caninum, respectively. It can be suggested that T. gondii and N. caninum are widespread in buffaloes in Paraíba, and that additional surveys are needed in order to ascertain the importance of these agents for this species and for pigs, and the influence of the farming type on occurrences of seropositive animals.

Os objetivos deste trabalho foram determinar a frequência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum e identificar os fatores de risco associados com as soropositividades em búfalos do Estado da Paraíba, Brasil. Foram utilizados 136 búfalos oriundos de 14 propriedades. Para a detecção de anticorpos anti-T. gondii e anti-N. caninum, foi empregada a reação de imunofluorescência indireta (RIFI). Das 136 amostras analisadas, 17 (12,5%) foram positivas para anticorpos anti-T. gondii, com títulos variando de 64 a 1.024; e 26 (19,1%) para anticorpos anti-N. caninum, com títulos de 200 a 1.600. Das 14 propriedades, em 10 (71,4%) houve animais soropositivos tanto para T. gondii como para N. caninum. O manejo semi-intensivo (odds ratio = 2,99) e a presença de suínos (odds ratio = 4,33) foram identificados como fatores de risco para T. gondii e N. caninum, respectivamente. Sugere-se que T. gondii e N. caninum estão disseminados em búfalos do Estado da Paraíba, bem como a necessidade de mais estudos acerca da importância desses agentes nessa espécie e em suínos, e da influência do tipo de criação na ocorrência de animais soropositivos.

Toxoplasma gondii and Neospora caninum in dogs from the state of Tocantins: serology and associated factors / Toxoplasma gondii e Neospora caninum em cães provenientes de Tocantins: sorologia e fatores associados

Abstract This study investigated occurrences of anti-Neospora caninum and anti-Toxoplasma gondii IgG antibodies by means of the enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFAT), along with risk factors associated with toxoplasmosis and neosporosis, in 204 dogs from urban and rural areas of the municipality of Araguaína, state of Tocantins, Brazil. One hundred and thirty samples (63.7%) were positive for T. gondii using ELISA: 57.1% and 70.7% in the urban and rural areas, respectively. The seropositivity frequency for T. gondii observed through IFAT was 57.4%, distributed between rural and urban areas as 62.6% and 52.4%, respectively. The factors associated with canine toxoplasmosis were age and breed (p<0.05). In relation to N. caninum, 88 samples (43.1%) were positive, according to ELISA, distributed as 42.9% in urban areas and 43.3% in rural areas. Anti - N. caninum antibodies were detected through IFAT in 62 dogs (30.4%), distributed as 31.3% and 29.5% between rural and urban areas, respectively. Age and breed were associated with neosporosis occurrence (p<0.05) by IFAT. This study provides the first detection of IgG antibodies for canine toxoplasmosis and neosporosis in the state of Tocantins and highlights the importance of dogs in the epidemiological chain of these diseases.

Resumo Este estudo investigou a ocorrência de anticorpos anti-Neospora caninum e anti-Toxoplasma gondii por ensaio imunoenzimático indireto (ELISA) e reação de imunofluorescência indireta (RIFI), assim como os fatores de risco associados à toxoplasmose e à neosporose em 204 cães provenientes de áreas urbana e rural do município de Araguaína, Estado de Tocantins, Brasil. Cento e trinta amostras (63,7%) foram positivas para T. gondii, destas 57,1% e 70,7% oriundas de áreas urbanas e rurais, respectivamente. Considerando-se o teste RIFI, a frequência de soropositividade para T. gondii foi de 57,4% com distribuição de 62,6% e 52,4% entre áreas rurais e urbanas, respectivamente. Fatores associados à toxoplasmose canina foram raça e idade, com soropositividade maior para animais mais velhos (p<0,05). Em relação à N. caninum, 88 (43,1%) amostras foram positivas, segundo ELISA, sendo distribuídas em 42,9% para área urbana e 43,3% para área rural. Por meio da RIFI, anticorpos anti-N. caninum foram detectados em 62 (30,4%) cães, sendo distribuídos em 31,3% e 29,5% entre áreas rurais e urbanas, respectivamente. Os fatores associados à ocorrência de neosporose, pela RIFI, foram idade e raça (p<0,05). Este estudo representa a primeira detecção de anticorpos IgG para toxoplasmose e neosporose canina no Estado de Tocantins e evidencia a importância de cães na cadeia epidemiológica dessas doenças.

Prevalence of antibodies against Toxoplasma gondii and Neospora caninum in dogs

Toxoplasmosis and neosporosis are parasitic diseases of global importance. The present study had the objective to determine the influence of age, sex and breed in the prevalence of antibodies against both diseases in dogs from Brotas city, São Paulo State, Brazil. Blood samples of 342 dogs were collected, and the age, sex and breed of each animal were recorded. The serological diagnosis for toxoplasmosis and neosporosis were performed using the immunofluorescent antibody test (IFAT). The Fischer's test was used to calculate the association probability of the variables, with a = 5%. For toxoplasmosis the prevalence of antibodies was 26.9% (CI 95% 22.4-31.8%), and for neosporosis 4.97% (CI 95% 3.1-7.8%). The statistical analysis revealed a higher risk of infection for T. gondii in dogs with more than five years.

Efficacy of a DNA Vaccine Carrying Eimeria maxima Gam56 Antigen Gene against Coccidiosis in Chickens

To control coccidiosis without using prophylactic medications, a DNA vaccine targeting the gametophyte antigen Gam56 from Eimeria maxima in chickens was constructed, and the immunogenicity and protective effects were evaluated. The ORF of Gam56 gene was cloned into an eukaryotic expression vector pcDNA3.1(zeo)+. Expression of Gam56 protein in COS-7 cells transfected with recombinant plasmid pcDNA-Gam56 was confirmed by indirect immunofluorescence assay. The DNA vaccine was injected intramuscularly to yellow feathered broilers of 1-week old at 3 dosages (25, 50, and 100 microg/chick). Injection was repeated once 1 week later. One week after the second injection, birds were challenged orally with 5x10(4) sporulated oocysts of E. maxima, then weighed and killed at day 8 post challenge. Blood samples were collected and examined for specific peripheral blood lymphocyte proliferation activity and serum antibody levels. Compared with control groups, the administration of pcDNA-Gam56 vaccine markedly increased the lymphocyte proliferation activity (P<0.05) at day 7 and 14 after the first immunization. The level of lymphocyte proliferation started to decrease on day 21 after the first immunization. A similar trend was seen in specific antibody levels. Among the 3 pcDNA-Gam56 immunized groups, the median dosage group displayed the highest lymphocyte proliferation and antibody levels (P<0.05). The median dosage group had the greatest relative body weight gain (89.7%), and the greatest oocyst shedding reduction (53.7%). These results indicate that median dosage of DNA vaccine had good immunogenicity and immune protection effects, and may be used in field applications for coccidiosis control.

Changing Patterns of Acute Phase Proteins and Inflammatory Mediators in Experimental Caprine Coccidiosis

This experiment was conducted to assess the changing patterns and relative values of acute phase proteins and inflammatory cytokines in experimental caprine coccidiosis. Eighteen newborn kids were allocated to 3 equal groups. Two groups, A and B, were inoculated with a single dose of 1x10(3) and 1x10(5) sporulated oocysts of Eimeria arloingi, respectively. The third group, C, received distilled water as the control. Blood samples were collected from the jugular vein of each kid in both groups before inoculation and at days 7, 14, 21, 28, 35, and 42 post-inoculation (PI), and the levels of haptoglobin (Hp), serum amyloid A (SAA), TNF-alpha, and IFN-gamma were measured. For histopathological examinations, 2 kids were selected from each group, euthanized, and necropsied on day 42 PI. Mean Hp concentrations in groups A and B (0.34 and 0.68 g/L) at day 7 PI were 3.2 and 6.3 times higher than the levels before inoculation. The mean SAA concentrations in groups A and B (25.6 and 83.5 microg/ml) at day 7 PI were 4.2 and 13.7 times higher than the levels before inoculation. The magnitude and duration of the Hp and SAA responses correlated well with the inoculation doses and the severity of the clinical signs and diarrhea in kids. These results were consistent with the histopathological features, which showed advanced widespread lesions in group B. In both groups, significant correlations were observed for TNF-alpha and IFN-gamma with SAA and Hp, respectively. In conclusion, Hp and SAA can be useful non-specific diagnostic indicators in caprine coccidiosis.

Emprego da RT-PCR em tempo real para a quantificação da expressão de genes associados à resposta imune em bezerros bovinos experimentalmente infectados por Neospora caninum / Use of the real time RT-PCR for immune related gene expression quantitation in experimentally infected Neospora caninum bovine calves

Neospora caninum é um dos principais agentes causadores de abortamentos e natimortalidade em bovinos. A defesa imune do hospedeiro é capaz de inibir a atividade dos taquizoítos na fase aguda da infecção, mas não age sobre os bradizoítos nos cistos teciduais. A ativação e a modulação dessa resposta de defesa são controladas por mediadores celulares. A técnica do RT-PCR em tempo real foi empregada para a detecção de alguns desses mediadores durante a infecção pelo N. caninum. Foram analisadas amostras de linfonodos poplíteos, fígado e córtex cerebral de bezerros Holandeses e Nelores infectados com taquizoítos por via intramuscular e controles não-infectados, abatidos no sexto dia pós-inoculação. A RT-PCR em tempo real detectou a expressão dos genes em todos os tecidos analisados. Não houve variação significativa na expressão do gene GADPH entre os grupos, a eficiência de amplificação desse foi similar aos demais genes testados e foi empregado como controle endógeno na análise. A comparação entre infectados e não-infectados permitiu a quantificação relativa da expressão gênica. A expressão dos genes IFN-γ e TNF-α apresentou elevação significante em algumas amostras. Os genes iNOS e TGF-β1 apresentaram algumas variações não-significativas e os valores de IL-4 e IL-10 permaneceram praticamente inalterados.

Neospora caninum is one of the main causes of abortion and natimortality in cattle. Host immune defense is capable to inhibit tachyzoite activity during acute infection, but there is no action against bradyzoites in tissue cysts. Activation and modulation of this response is controlled by cell mediators. The real-time RT-PCR technique was employed to detect some of those mediators during N. caninum infection. Holstein and Nelore calves intramuscularly infected with tachyzoites and uninfected controls were slaughtered at the sixth day post-infection and popliteal lymph node, liver and brain cortex samples were analyzed. Real-time RT-PCR detected gene expression in all tissues. No significant variation of GAPDH gene expression was detected among groups, its amplification efficiency was similar to the other genes tested and it was used as the endogenous control for the analysis. Comparisons between infected and uninfected groups allowed the relative gene expression quantification. IFN-γ and TNF-α genes showed increased expression in some samples. iNOS and TGF-β1 genes had some non-significant variations and IL-4 and IL-10 stayed pratically inaltered.

Antibody dynamics during gestation in cows naturally infected with Neospora caninum from four dairy herds in Brazil / Dinâmica de anticorpos durante a gestação em vacas naturalmente infectadas com Neospora caninum de quatro rebanhos leiteiros no Brasil

Neospora caninum has been described as an important cause of abortion in bovine worldwide. The objective of the present study was to characterize patterns of antibody dynamics during gestation in dairy cows naturally infected with N. caninum. Twelve N. caninum naturally infected cows were selected from four dairy herds from Brazil and blood samples were monthly collected during pregnancy. Serum were tested for antibodies against N. caninum by Indirect Fluorescent Antibody Test (IFAT). During this period, all cows remained clinically normal and gave birth to healthy calves. The cows remained seropositives during the study and N. caninum IFAT titers ranged from 100 to 12,800; only animal 234 presented one negative result in the first month of pregnancy. Significant differences of N. caninum IFAT titers were found between months from 1 to 9 of pregnancy bythe Friedman Test (P<0.001). The statistical analysis showed an increase of N. caninum antibody titers from second and third trimester of pregnancy in relation to first trimester. High titers were observed in few cows after month fifth of pregnancy. This study showed a variation of specific antibody levels in seropositive cows during different gestational periods. The highest values were observed during the second and third trimester. The antibody increase after the fifth month of gestation was not associated to abortion.

Neospora caninum é descrito como uma importante causa de abortamento em bovinos por todo o mundo. O objetivo do presente estudo foi caracterizar o padrão da dinâmica de anticorpos durante a gestação em vacas leiteiras infectadas naturalmente por N. caninum. Doze vacas gestantes infectadas naturalmente com N.caninum foram selecionadas de quatro rebanhos leiteiros do Brasil e amostras de sangue foram mensalmente colhidas da concepção até o parto das vacas. Soros foram testados para anticorpos contra N. caninum pela reação de imunofluorescência indireta (RIFI). Durante a gestação, todas as vacas permaneceram clinicamente normais e geraram bezerros saudáveis. As vacas permaneceram soropositivas durante o estudo e títulos de anticorpos anti-N.caninum variaram de 100 a 12.800; somente o animal 234 apresentou um resultado negativo no primeiro mês de gestação. Diferenças significativas dos títulos da RIFI para N. caninum foram encontradas entre os meses de 1 a 9 de gestação pelo Teste de Friedman (P<0,001). As análises estatísticas mostraram um aumento dos títulos de anticorpos anti-N. caninum no segundo e terceiro trimestre de gestação em relação ao primeiro trimestre. Altos títulos de anticorpos foram observados em algumas vacas após o mês cinco de gestação. Este estudo mostrou variação dos níveis de anticorpos em vacas soropositivas durante diferentes períodos gestacionais. Altos títulos foram observados durante o segundo e terceiro trimestre e o aumento dos títulos de anticorpos após o quinto mês de gestação não foi associado a abortamentos.

[Serological study of Neospora caninum infection in cattle from Ahvaz area, Iran]

In order to investigate the seroprevalence of Neospora caninum infection in cattle in Southwestern Iran, blood samples were collected from Holstein [121 animals] and cross-breed [436 animals] cattle from three farms and seven areas of Ahvaz, respectively. All of the Holstein cattle were >/= 4 years old but cross-breed cattle were from different age groups [< 2.2-4.5-6 and > 6 years old]. Sera were examined by commercial ELISA kit. Anti - N. caninum antibodies were detected in 117 [21%] sera out of 557 tested. A Significant difference was found between Holstein [53.71%] and cross-breed [11.93%] cattle although there were not any significant differences between age groups

Use of an immunodominant p17 antigenic fraction of Neospora caninum in detection of antibody response in cattle

A Neospora caninum 17 kDa protein fraction (p17) has been described as an immunodominant antigen (IDA) under reducing and non-reducing conditions. The aim of the present study was to investigate the diagnostic utility of p17 in cattle. In order to achieve this, p17 was purified by electroelution from whole N. caninum tachyzoite soluble extract and a p17-based Western blot (WB-p17) was developed. The p17 recognition was measured by densitometry and expressed as OD values to check the validity of the WB-p17. A total of 131 sera including sequential samples from naturally- and experimentally-infected calves and breeding cattle were analysed by WB-p17 and compared with IFAT using whole formalin-fixed tachyzoites as a reference test. The results obtained highlight the feasibility of using the N. caninum p17 in a diagnostic test in cattle. Firstly, the assay based on the p-17 antigen discriminated between known positive and negative sera from different cattle populations, breeding cattle and calves. Secondly, the p17 antigen detected fluctuations in the antibody levels and seroconversion in naturally- and experimentally-infected cattle. Significant differences in p-17 antigen recognition were observed between naturally infected aborting and non-aborting cattle, as well as significant antibody fluctuations over time in experimentally infected cattle, which varied between groups. Furthermore, the results obtained with WB-p17 are in accordance with the results obtained with the IFAT, as high agreement values were obtained when all bovine subpopulations were included (kappa = 0.86).

Neosporosis bovina: conceptos generales, inmunidad y perspectivas para la vacunación / Bovine neosporosis: general concepts, immunity and perspectives for vaccination

Neospora caninum es agente causal de aborto en bovinos de regiones ganaderas de todo el mundo. Su ciclo de vida es heteroxeno siendo el perro (Canis familiaris) y el coyote (Canis latrans) los hospedadores definitivos reconocidos hasta el presente. La infección transplacentaria es un eficiente mecanismo de transmisión de la enfermedad pero existe evidencia que demuestra la transmisión postnatal en los bovinos. Debido a las pérdidas económicas que causa la neosporosis, diversas técnicas diagnósticas han sido desarrolladas. La fisiopatología del aborto causado por N. caninum no ha sido completamente esclarecida. La modulación del sistema inmune por efecto de la preñez ocasiona un período de susceptibilidad al aborto por N. caninum. Aunque la resistencia al parásito ha sido asociada con una respuesta de linfocitos T tipo 1, dicha respuesta inmune es incompatible con una preñez exitosa. Sin embargo, los mecanismos inmunes presentes en animales crónicamente infectados protegen del aborto ante una segunda exposición al protozoo. La comprensión de esa respuesta inmune adquirida constituye un desafío para el desarrollo de inmunógenos. Este trabajo menciona conceptos generales de la neosporosis bovina haciendo énfasis en los mecanismos inmunes y las perspectivas para la vacunación.

Neospora caninum causes abortions in cattle worldwide. The Neospora-cycle of life is heteroxenous. Dogs (Canis familiaris) and coyotes (Canis latrans) are the definitive hosts known at present. Although, transplacental infection is an efficiently mode of transmission in cattle; there are also experimental and field data that prove horizontal transmission. Several techniques are available for diagnosis since neosporosis is recognized as a disease that causes economic losses in cattle. The mechanisms that produce the abortion are not completely understood. The immunomodulation observed during the pregnancy, is associated with a susceptible period where Neospora-abortion can occur. Resistance to the parasite is dependent on T helper cell 1 cytokine responses. This has important repercussions for pregnant female bovine because strong T helper cell 1 cytokine responses are incompatible with successful pregnancy. However, it was demonstrated that chronically infected cows develop immune mechanisms against the abortion caused by a second Neospora-exposure. The comprehension of those mechanisms is needed for the formulation of Neospora-vaccines that prevent bovine neosporosis. General concepts about neosporosis with emphasis in the immune response and perspectives for vaccination are mentioned in the present review.

Coccidiosis aviar / Avian coccidiosis

Las coccidiosis se consideran como los parásitos más importantes de los vertebrados, afectando principalemnte a las aves y mamiferos. Estos parásitos tienen un gran potencial de reproducción y transmisión además se adaptan en el transcurso de su evolución a un elevado número de especies de animales, a los cuales penetran y colonizan a la mayoría de sus células, tejidos, órganos y sistemas. Se explican los mecanimos bioquímicos, metabólicos e inmunológicos de estos parásitos al igual que los cambios fisiopatológicos que causan a sus hospedadores. Se describen las medidas de tratamiento y control por medio de quimioterapia e indica sus fallas, en la aplicación de las drogas. Por otra parte presenta un tratamiento anticocciodial en el agua bebida con el uso de los productos: sulfanamidas, amprolium y toltrazuril. Se describen las técnicas aplicadas en el estudio de la coccidiosis