title: Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution.
abstract: The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Castaño
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Fuertes
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Regidor-Cerrillo
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ferre
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Fernández
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Ferreras
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moreno-Gonzalo
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Camino
authors.initials: C
authors.lastname: González-Lanza
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Juana
authors.initials: J
authors.lastname: Pereira-Bueno
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Katzer
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Ortega-Mora
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain.
authors.forename: Valentín
authors.initials: V
authors.lastname: Pérez
authors.affiliation: Departamento de Sanidad Animal, Instituto de Ganadería de Montaña (CSIC-ULE), Grulleros, 24346, León, Spain. j.benavides@eae.csic.es.
authors.forename: Julio
authors.identifier: http://orcid.org/0000-0001-9706-100X
authors.initials: J
authors.lastname: Benavides
mesh_terms: D000367:Age Factors; D000818:Animals; D005260:Female; D005333:Fetus / Q000469:parasitology / Q000473:pathology; D005865:Gestational Age; D010920:Placenta / Q000469:parasitology / Q000473:pathology; D011247:Pregnancy; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology* / Q000473:pathology; D014122:Toxoplasma / Q000502:physiology*; D014124:Toxoplasmosis, Animal / Q000469:parasitology* / Q000473:pathology