CHARACTERIZATION OF AN OUTBRED PREGNANT MOUSE MODEL OF NEOSPORA CANINUM INFECTION

SUMMARYThe intraspecific diversity of Neospora caninum is a determinant for in vivo parasite virulence and in vitro parasite behaviour. The relationship between isolate virulence and specific antibody responses against key parasite proteins has not been well characterized. The response kinetics and the differences in specific anti-rNcGRA7, -rNcSAG4, -rNcBSR4 and -rNcSRS9 antibody levels were analysed by recombinant protein-based ELISA in groups of mice inoculated with 10 different N. caninum isolates that differ in their virulence. The majority of the virulence parameters analysed correlated with the specific antibody levels against the 4 recombinant proteins. The antibodies developed against the highly immunogenic protein NcGRA7 were significantly higher in mice inoculated with high virulence isolates than in those inoculated with low-to-moderate virulence isolates in both non-pregnant and pregnant mouse models. Moreover, these levels were correlated with the anti-N. caninum IgG1 and IgG2a responses and the in vitro tachyzoite yield at 56 h. The antibodies directed against the bradyzoite-specific proteins were not detected in a non-pregnant mouse model. However, some seropositive mice were found in groups inoculated with high virulence isolates in a pregnant mouse model. NcGRA7 and NcSAG4 are proteins clearly correlated with virulence, and to a lesser extent NcBSR4 and NcSRS9 proteins. Moreover, antibodies to bradyzoite-specific proteins appear to also be related to virulence in mice. Further analyses should be performed in order to verify the usefulness of these proteins as predictive markers for virulence in an experimental bovine model of neosporosis.

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Histopathological findings and immunohistochemical staining of Neospora caninum infection in placentas of animals for slaughter

Semina Ciências Agrárias ◽

10.5433/1679-0359.2018v39n5p2287 ◽

2018 ◽

Vol 39 (5) ◽

pp. 2287

Author(s):

Allana Freitas Barros ◽

Higor Ferreira Silva ◽

Renata Mondêgo de Oliveira ◽

Nathálya Dos Santos Martins ◽

Mylena Andréa Oliveira Torres ◽

...

Keyword(s):

Histological Analysis ◽

Neospora Caninum ◽

Small Ruminants ◽

Parasitic Disease ◽

Histopathological Changes ◽

Cattle Production ◽

Caninum Infection ◽

Bovine Neosporosis ◽

The City

Bovine neosporosis is a parasitic disease caused by the protozoan Neospora caninum, which is one of the main pathogens that cause abortions in cattle worldwide. It is responsible for large losses in dairy and beef cattle, especially with regard to the expenses associated with decreased productivity and increased discard. In the State of Maranhão, the occurrence of this parasite has already been confirmed in the dairy cattle of three microregions that make up the state’s dairy industry and in small ruminants of the municipalities of Amarante do Maranhão and Buritirana. This fact justifies the importance of determining the presence of N. caninum in cattle slaughtered in the slaughterhouses of the Island of São Luís, to help control the parasitic cycle in the cattle production system of the region under study, and the importance of its diagnosis. The objective of the research was to conduct a histopathological and immunohistochemical characterization of bovine placentas infected with N. caninum collected in slaughterhouses. Sixteen placenta samples from cows were randomly selected at the slaughterhouses of the city of São Luís for histological analysis and immunohistochemistry. Results showed that 31% of the placentas presented histopathological changes such as: inflammatory process, edema, hemorrhage and presence of hemosiderin. All slides with histopathological changes showed immunolabeling for N. caninum.

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Vaccination with the recombinant chimeric antigen recNcMIC3-1-R induces a non-protective Th2-type immune response in the pregnant mouse model for N. caninum infection

Vaccine ◽

10.1016/j.vaccine.2012.08.024 ◽

2012 ◽

Vol 30 (46) ◽

pp. 6588-6594 ◽

Cited By ~ 9

Author(s):

Thierry Monney ◽

Karim Debache ◽

Denis Grandgirard ◽

Stephen L. Leib ◽

Andrew Hemphill

Keyword(s):

Immune Response ◽

Mouse Model ◽

Pregnant Mouse ◽

Caninum Infection

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Dose-dependent effects of experimental infection with the virulent Neospora caninum Nc-Spain7 isolate in a pregnant mouse model

Veterinary Parasitology ◽

10.1016/j.vetpar.2015.05.021 ◽

2015 ◽

Vol 211 (3-4) ◽

pp. 133-140 ◽

Cited By ~ 20

Author(s):

David Arranz-Solís ◽

Adriana Aguado-Martínez ◽

Joachim Müller ◽

Javier Regidor-Cerrillo ◽

Luis Miguel Ortega-Mora ◽

...

Keyword(s):

Mouse Model ◽

Experimental Infection ◽

Neospora Caninum ◽

Pregnant Mouse ◽

Dose Dependent

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Vaccination with Neospora GRA6 Interrupts the Vertical Transmission and Partially Protects Dams and Offspring against Neospora caninum Infection in Mice

Vaccines ◽

10.3390/vaccines9020155 ◽

2021 ◽

Vol 9 (2) ◽

pp. 155

Author(s):

Ragab M. Fereig ◽

Hanan H. Abdelbaky ◽

Yoshifumi Nishikawa

Keyword(s):

Vertical Transmission ◽

Neospora Caninum ◽

Protective Efficacy ◽

Parasite Burden ◽

Clinical Score ◽

Pregnant Mouse ◽

Dense Granule ◽

Economic Losses ◽

Caninum Infection ◽

Preventative Measures

Vaccination is the mainstay of preventative measures for numerous infectious diseases. Neospora caninum infection induces storms of abortion in pregnant cows and ewes, resulting in drastic economic losses because of fetal losses and culling of the dams. Herein, we evaluated the potential of recombinant protein of N. caninum dense granule protein 6 fused with glutathione-S-transferase (NcGRA6+GST) as a vaccine candidate against neosporosis in a pregnant mouse model. The protective efficacy was investigated by subcutaneous inoculation of BALB/c mice with recombinant NcGRA6+GST (25 pmol), and GST alone (25 pmol) or phosphate-buffered saline (PBS) as the controls. This study revealed the partial ability of NcGRA6+GST to protect the dams and offspring from N. caninum infection during the critical period of pregnancy. This ability was revealed by higher survival rate and lower parasite burden in brains of offspring of the NcGRA6+GST-immunized group in comparison with the control groups. In addition, mouse dams from NcGRA6+GST-immunized groups exhibited lower clinical score and minimum alteration in body weight in comparison with PBS or GST groups after challenge with N. caninum tachyzoites. Taken together, our results suggest the efficacy of recombinant NcGRA6 for interrupting the vertical transmission of N. caninum in mice by reducing the severity of infections in dams and offspring.

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