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Neospora and neosporosis: achievement and perspectives in diagnosis

100%

Ortega-Mora L. M., Gomez-Bautista M., Fernandez-Garcia A.

Wiadomości Parazytologiczne. Suplement

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2005

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tom 51

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Diagnosis of bovine neosporosis: Recent advances and perspectives

100%

Ortega-Mora L. M., Fernandez-Garcia A., Gomez-Bautista M.

Acta Parasitologica

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2006

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tom 51

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nr 1

Neospora caninum is considered a major cause of abortion in cattle. Appropriate techniques for diagnosis of bovine neosporosis, both in vivo and in aborted foetuses, have been developed in the last ten years and some of them are commercially available. For diagnosis in live animals, detection of antibodies in serum or milk has been shown to be the best option both at the herd and the individual level. These techniques are excellent tools to examine N. caninum-associated abortion problems and to adopt some basic herd-control measures. Concerning foetal diagnosis, detection of compatible lesions by histological examination and parasites by PCR in brain (as well as heart and liver) are the best choices. Diagnostic criteria to distinguish foetal infection and Neospora-associated abortion are based not only on the demonstration of the parasite in the foetus but also on the extent and severity of the lesions in the foetus, foetal age and the assessment of neosporosis at the herd level. In the near future, new tools to diagnose infection should help to detect animals with parasite reactivation by testing the immune response to stage-specific antigens and lead to the development of molecular typing methods to characterise different parasite isolates. Finally, uniform diagnostic procedures need to be established between laboratories and countries in order to standardise result interpretation. The role of National or Regional Reference Laboratories is essential in countries or regions where control programmes for the disease are being developed.

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Isolation and biological characterisation of a new isolate of Neospora caninum from an asymptomatic calf in Brazil

76%

Garcia-Melo D. P., Regidor-Cerrillo J., Ortega-Mora L. M., Collantes-Fernandez E., Ferreira de Oliveira V. S., Pelli de Oliveira M. A., Caetano da Silva A.

Acta Parasitologica

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2009

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tom 54

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nr 2

180-185

Neospora caninum is a tissue-cyst forming parasite that has been recognized worldwide as a cause of abortion in cattle. Despite the ubiquitous distribution of this parasite and its broad range of hosts, the number of N. caninum isolates obtained to date is limited. In addition, the majority of isolates have been obtained from clinically affected hosts, therefore potentially biasing this population towards more virulent isolates. This report describes the isolation and biological characterisation of a new N. caninum isolate, Nc-Goiás 1, obtained from an asymptomatic, naturally infected calf from Brazil. This new isolate was identified as a member of the N. caninum species by polymerase chain reaction (PCR) using specific primers based on the N. caninum internal transcribed spacer 1 (ITS-1) sequence, and was genetically identified at multiple loci using microsatellite analysis. Finally, a pathogenicity study was conducted in a BALB/c mice model. All Nc-Goiás 1-infected mice survived without exhibiting any clinical signs. Further pathogenic characterisation of this isolate suggested that Nc-Goiás 1 is less virulent than other N. caninum isolates (Nc-Liv and Nc-1) studied in this mouse model. This is the first report of the isolation and biological characterisation of N. caninum from an infected but clinically healthy calf in South America.

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Characterisation of NcGRA7 and NcSAG4 proteins: immunolocalisation and their role in the host cell invasion by Neospora caninum tachyzoites

76%

Aguado-Martinez A., Alvarez-Garcia G., Schares G., Risco-Castillo V., Fernandez-Garcia A., Marugan-Hernandez V., Ortega-Mora L. M.

Acta Parasitologica

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2010

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tom 55

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nr 4

304-312

Neospora caninum negatively impacts bovine reproductive performance around the world. Addressing this problem requires a greater understanding of the parasite’s molecular biology. In this study, monoclonal antibodies against recombinant proteins were successfully developed and employed to characterise two different proteins of N. caninum: the acute phase-associated NcGRA7 and the chronic phase-associated NcSAG4. Immunofluorescence with the anti-rNcGRA7 monoclonal antibody suggested that NcGRA7 trafficks from tachyzoite dense granules to the matrix of the parasitophorous vacuole and parasite’s surroundings. Furthermore, NcGRA7 is also expressed in the bradyzoite stage and localised on the matrix of bradyzoite-positive vacuoles. NcGRA7 appears to be partially involved in the tachyzoite-invasion mechanisms, as an anti-rNcGRA7 monoclonal antibody partially inhibited in vitro tachyzoite-invasion. A monoclonal antibody specific for NcSAG4 confirmed this protein’s bradyzoitespecific expression both by western blot and immunofluorescence. However, some bradyzoite-positive vacuoles only weakly expressed NcSAG4, if it was expressed at all. The specificity of the anti-rNcSAG4 monoclonal antibody was confirmed by the recognition of the NcSAG4 in the membrane surface of Nc-1SAG4c transgenic tachyzoites, which constitutively expresses NcSAG4. Blocking NcSAG4 of Nc-1SAG4c tachyzoites with the monoclonal antibody did not affect host cell invasion. However, its implication on the host cell adhesion or host immune evasion should not be discarded.

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Intrauterine Neospora caninum inoculation using contaminated semen with different numbers of tachyzoites

64%

Serrano E., Ferre I., Osoro K., Aduriz G., Mota R. A., Martinez A., Atxaerandio R., Hidalgo C. O., Ortega-Mora L. M.

Wiadomości Parazytologiczne. Suplement

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2005

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tom 51

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Detection of Neospora caninum in the semen and blood during acute and chronic experimental neosporosis in bulls

64%

Ferre I., Martinez A., Serrano E., Osoro K., Mateos-Sanz A., Tamargo C., Hidalgo C. O., del-Pozo I., Aduriz G., Ortega-Mora L. M.

Wiadomości Parazytologiczne. Suplement

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2005

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tom 51

7

Neosporosis and toxoplasmosis in South American camelids from Peru

64%

Serrano-Martinez E., Chavez-Velasquez A., Collantes-Fernandez E., Alvarez-Garcia G., Casas-Astos E., Rosadio-Alcantara R., Risco-Castillo V., Ortega-Mora L. M.

Wiadomości Parazytologiczne. Suplement

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2005

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tom 51

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Pathological and immunological findings in placentas from pregnant BALB/c mice infected with Neospora caninum at early and late stages of gestation

64%

Lopez-Perez I. C., Collantes-Fernandez E., Rojo-Montejo S., Navarro-Lozano V., Risco-Castillo V., Perez-Perez V., Pereira-Bueno J., Ortega-Mora L. M.

Acta Parasitologica

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2011

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tom 56

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nr 3

Neospora caninum is transmitted from a cow to its foetus by vertical transmission and the timing of infection in gestation is an important factor in determining the disease outcome. Few studies have explored the role of the placenta in the outcome of N. caninum infection during pregnancy. Here, we described the N. caninum presence, parasite load, local immune response, and histopathological lesions at the materno-foetal interface after infection of BALB/c mice at early and late stages of gestation. In mice infected at early gestation, N. caninum DNA was detected in foetoplacentary units 7 days post-infection (PI) and in the placenta, but not in viable foetuses on day 14 PI, indicating that the parasite was multiplying primarily in the placental tissues without reaching the foetus. Moreover, parasite DNA was detected in resorptions, suggesting that foetal death could be a consequence of infection. An increase in IFN-γ, TNF-α and IL-10 expression was observed in N. caninum PCR-positive placentas, which could favour N. caninum foetal transmission and be harmful to both the placenta and the foetus. Histopathological analysis revealed necrosis affecting both the maternal and foetal sides of the placenta. At late gestation, transmission occurred rapidly following infection (day 3 PI), but parasite were rarely found. In addition, an increase in cytokine expression was observed in spleen and placental tissues from infected animals, while a downregulation in IL-4 expression was only observed in the spleen. Finally, necrosis in the placenta was limited to the maternal side, suggesting that the parasite is mainly multiplying in the placental tissue at this stage. Thus, the results of the present study indicate that the placenta may be actively involved in N. caninum pathogenesis.

Ograniczanie wyników

Neospora and neosporosis: achievement and perspectives in diagnosis

Diagnosis of bovine neosporosis: Recent advances and perspectives

Isolation and biological characterisation of a new isolate of Neospora caninum from an asymptomatic calf in Brazil

Characterisation of NcGRA7 and NcSAG4 proteins: immunolocalisation and their role in the host cell invasion by Neospora caninum tachyzoites

Intrauterine Neospora caninum inoculation using contaminated semen with different numbers of tachyzoites

Detection of Neospora caninum in the semen and blood during acute and chronic experimental neosporosis in bulls

Neosporosis and toxoplasmosis in South American camelids from Peru

Pathological and immunological findings in placentas from pregnant BALB/c mice infected with Neospora caninum at early and late stages of gestation