%0 Journal Article
%A Jiménez‑Pelayo, Laura
%A García Sánchez, Marta Eulalia
%A Vázquez Arbáizar, María Patricia
%A Regidor‑Cerrillo, Javier
%A Horcajo Iglesias, María Del Pilar
%A Collantes Fernández, Esther
%A Blanco Murcia, Francisco Javier
%A Gutiérrez Expósito, Daniel
%A Román Trufero, Alicia
%A Osoro, Koldo
%A Benavides, Julio
%A Ortega Mora, Luis Miguel
%T Early Neospora caninum infection dynamics in cattle after inoculation at mid‑gestation with high (Nc‑Spain7)‑ or low (Nc‑Spain1H)‑virulence isolates
%D 2019
%@ 1297-9716
%U https://hdl.handle.net/20.500.14352/116342
%X Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.
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