Effects of challenge dose and inoculation route of the virulent Neospora caninum Nc-Spain7 isolate in pregnant cattle at mid-gestation

Autor: Silvia Rojo-Montejo, Miguel Fernández, Koldo Osoro, Laura Jiménez-Pelayo, Marta García-Sánchez, Pilar Horcajo, Alicia Román-Trufero, Javier Regidor-Cerrillo, Luis Miguel Ortega-Mora, Patricia Vázquez, Julio Benavides
Přispěvatelé: Ministerio de Economía y Competitividad (España), Universidad Complutense de Madrid, CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM)
Rok vydání: 2019
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Veterinary Research
Veterinary Research, BioMed Central, 2019, 50 (1), pp.68. ⟨10.1186/s13567-019-0686-3⟩
Veterinary Research, Vol 50, Iss 1, Pp 1-14 (2019)
ISSN: 0928-4249
1297-9716
DOI: 10.1186/s13567-019-0686-3⟩
Popis: Parameters such as pathogen dose and inoculation route are paramount in animal models when studying disease pathogenesis. Here, clinical findings, including foetal mortality, parasite transmission rates and lesion severity, and immune responses were evaluated in Asturiana pregnant heifers at day 110 of gestation challenged with a virulent (Nc-Spain7) Neospora caninum isolate. Four different doses of parasite tachyzoites were inoculated intravenously (IV1, 107 parasites, n = 6; IV2, 105, n = 6; IV3, 103, n = 6; and IV4, 102, n = 5), and the subcutaneous (SC) inoculation route was also assessed for the dose of 105 tachyzoites (SC, n = 6). In addition, a control group (n = 4 pregnant heifers) was evaluated. Foetal death was observed in all infected groups from 25 to 62 days post-infection, varying with the dose (IV1:4/6, IV2:3/6; IV4:2/5, IV3:1/6), and was three times less frequently associated with the SC route than IV inoculation (1/6 vs. 3/6). A dose-dependent effect for parasite loads in placental and foetal brain tissues was also detected. After SC challenge, a reduced number of tachyzoites were able to reach foetal brain tissues, and no lesions were observed. In calves, specific IgG responses in precolostral sera were mainly associated with high-dose groups (IV1 [100.0%] and IV2 [66.7%]), and cerebral parasite DNA detection was scarce (3/18). In dams, IFN-γ production and the dynamics of anti-N. caninum IgG antibodies varied with the dose, and the cell-mediated immune response was also found to be route-dependent. Our results confirm the influence of parasite dose and inoculation route on the outcome and dynamics of bovine neosporosis at mid-gestation.
Patricia Vázquez had a Juan de la Cierva-Formación post-doctoral contract (FJCI-2014-20982) from the Spanish Ministry of Economy and Competitiveness (MINECO). Laura Jiménez-Pelayo was founded by UCM-Santander and Marta García-Sánchez was founded by MINECO (BES-2014-070723). Alicia Román-Trufero was supported by a 4-year FPI-INIA fellowship from the Spanish National Institute for Agriculture and Food Research and Technology (INIA).
Databáze: OpenAIRE
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