The extent of parasite-associated necrosis in the placenta and foetal tissues of cattle following Neospora caninum infection in early and late gestation correlates with foetal death
Autor: | Alexander J. Trees, Anne Rosbottom, Udo Hetzel, C. S. Guy, E. Helen Gibney, Diana L. Williams, Anja Kipar, Robert Smith |
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Rok vydání: | 2008 |
Předmět: |
Pathology
medicine.medical_specialty Necrosis Placenta Cattle Diseases Gestational Age Polymerase Chain Reaction Fetus Pregnancy parasitic diseases medicine Animals Parasite hosting Fetal Death reproductive and urinary physiology biology Coccidiosis Neospora Epithelial Cells DNA Protozoan biology.organism_classification medicine.disease Neospora caninum Microscopy Electron Mononuclear cell infiltration Infectious Diseases medicine.anatomical_structure Pregnancy Complications Parasitic embryonic structures Gestation Cattle Female Parasitology medicine.symptom |
Zdroj: | International Journal for Parasitology. 38:579-588 |
ISSN: | 0020-7519 |
DOI: | 10.1016/j.ijpara.2007.09.015 |
Popis: | The protozoan parasite Neospora caninum is the most frequently diagnosed abortifacient in the UK and a leading cause of abortion worldwide but the mechanisms leading to abortion are not fully understood. The distribution of parasites and the histopathological changes in the placenta and foetus were compared in 12 cows following experimental infection of cattle with N. caninum in early (n=6) and late (n=6) gestation, by PCR, immunohistology, light microscopy and transmission electron microscopy. Twelve uninfected pregnant cattle were used as controls. Infection in early gestation led to foetal death. In the placentae of cattle immediately following foetal death, N. caninum DNA was detected and there was evidence of widespread parasite dissemination. This was associated with extensive focal epithelial necrosis, serum leakage and moderate maternal interstitial mononuclear cell infiltration. In the foetuses, parasites were evident in all tissues examined and were associated with necrosis. In the placenta of cattle infected in late gestation, N. caninum DNA was detected sporadically but parasites were not evident immunohistologically. Small foci of necrosis were seen associated with mild interstitial mononuclear cell infiltration. Detection of N. caninum DNA in the foetuses was sporadic and parasites were demonstrated immunohistologically in brain and spinal cord only, with an associated mononuclear cell infiltration. This data is consistent with uncontrolled parasite spread in an immunologically immature foetus and could, via multiparenchymal necrosis of foetal tissues or the widespread necrosis and inflammation observed in the placenta, be the cause of Neospora-associated abortions. |
Databáze: | OpenAIRE |
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