title: Congenital Toxoplasmosis in Chronically Infected and Subsequently Challenged Ewes.
abstract: This experiment studied congenital transmission in sheep experimentally infected with oocysts of Toxoplasma gondii and reinfected at one of three stages of pregnancy. Twenty ewes were experimentally infected with T. gondii strain ME49 (day 0). After the T. gondii infection became chronic (IFAT≤512), the ewes were allocated with rams for coverage. After the diagnosis of pregnancy, these ewes were allocated into four experimental groups (n = 5): I-reinfected with T. gondii on the 40th day of gestation (DG); II-reinfected on DG 80; III-reinfected on DG 120; and IV-saline solution on DG 120 (not reinfected). Five ewes (IFAT<64) were kept as negative controls (uninfected, group V), therefore in groups I-III were infected prior to pregnancy and re-infected during pregnancy, group IV was only infected prior to pregnancy, and group V was not infected. Parasitism by T. gondii was investigated (histopathology, immunohistochemistry, mouse bioassay and PCR) in mothers and lambs tissue. All ewes produced lambs serologically positive for T. gondii. The results of the mouse bioassay, immunohistochemistry and PCR assays revealed the presence of T. gondii in all 20 sheep and their lambs. The congenital transmission of T. gondii was associated with fetal loss and abnormalities in persistently infected sheep and in ewes infected and subsequently reinfected by this protozoan. Therefore, congenital T. gondii infection was common when ewes were chronically infected prior to pregnancy, with or without reinfection during at various stages of gestation.
authors: Department of Veterinary Medicine, Rondônia Federal University (UNIR), Rolim de Moura, Av. Norte-Sul, 7300 - Rolim de Moura, RO, 76940-000, Brazil.
authors: Thaís Rabelo
authors: TR
authors: Dos Santos
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Gabriela da Silva Magalhães
authors: GD
authors: Faria
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Bruna Martins
authors: BM
authors: Guerreiro
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Nathalia Helena Pereira da Silva
authors: NH
authors: Dal Pietro
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Welber Daniel Zanetti
authors: WD
authors: Lopes
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Helenara Machado
authors: HM
authors: da Silva
authors: Department of Preventive Veterinary Medicine, UEL - Londrina, SP, Brazil.
authors: João Luis
authors: JL
authors: Garcia
authors: Department of Clinic, Surgery and Animal Reproduction, FMVA, UNESP - Araçatuba, SP, Brazil.
authors: Maria Cecília Rui
authors: MC
authors: Luvizotto
authors: Department of Production and Animal Health, FMVA, UNESP - Araçatuba, SP, Brazil.
authors: Katia Denise Saraiva
authors: KD
authors: Bresciani
authors: Department of Animal Pathology, CPPAR, FCAV, UNESP - Jaboticabal, Access road, Prof. Paul Donato Castellane s/n - Jaboticabal, SP, 14884-900, Brazil.
authors: Alvimar José
authors: AJ
authors: da Costa
mesh_terms: D000818:Animals; D002908:Chronic Disease; D016054:DNA, Protozoan / Q000235:genetics; D005260:Female; D056724:Immunity, Humoral; D051379:Mice; D033661:Oocysts / Q000469:parasitology; D009928:Organ Specificity; D011247:Pregnancy; D012756:Sheep; D014122:Toxoplasma / Q000235:genetics / Q000502:physiology; D014125:Toxoplasmosis, Congenital / Q000276:immunology / Q000473:pathology
chemical_list: D016054:DNA, Protozoan