Interacción hospedador/parásito en la toxoplasmosis ovina: influencia de la virulencia del parásito sobre la respuesta inmunitaria y la patogenia de la enfermedad

[EN] Toxoplasmosis is a protozoan infectious disease caused by the parasite Toxoplasma gondii. It is an important disease in both in Europe and globally due to its zoonotic potential and the reproductive failure it triggers in livestock, mainly in sheep, which results in heavy economic losses. Despite the fact that there are multiple methods for controlling this disease, such as management, vaccination or treatment; toxoplasmosis is still a very relevant animal health and public problem. There are still many unknown mechanisms of the pathogenesis of ovine toxoplasmosis, mainly regarding the occurrence of abortions. On the other hand, there are evidences that the variability of T. gondii isolates could influence the pathogenesis of the disease in murine models and humans’ observational studies. However, little is known regarding the influence of this variation in sheep. Bearing in mind that extrapolation of results between species is not always possible, it is necessary to study how the genotypic and phenotypic variability of T. gondii isolates could influence the development of the disease in pregnant sheep. For this, it is essential to use an experimental model of pregnant sheep, as the placenta and fetus are the main targets of the parasite. In order to clearly identified lesions caused by the disease, a detailed analysis of the morphological and physiological findings in both placenta and fetuses is also necessary. Thus, the aim of this PhD Thesis is to analyze the influence of T. gondii isolates variability on parasite/host interaction in ovine toxoplasmosis and the consequences it may have on pregnant sheep. For this purpose, four studies have been conducted, focused in four specific objectives and based on two different experiments (Experiment 1 and 2). An in vitro assay with ovine macrophages derived from peripheral blood monocytes (OvMØs) was developed for the evaluation of the influence of isolates variability on these cells (Experiment 1). Then an in vivo experimental model with pregnant sheep was carried out, where the animals were orally infected with low doses of three genetic and phenotypically different T. gondii isolates (Experiment 2).

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Bibliographic Details
Main Author: Vallejo García, Raquel
Other Authors: Pérez Pérez, Valentín
Format: tesis doctoral biblioteca
Language:Spanish / Castilian
Published: Universidad de León 2023-01-24
Subjects:Sanidad animal, Toxoplasmosis, Equinococosis quística, Toxoplasma gondii,
Online Access:http://hdl.handle.net/10261/350198
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