Congenital Toxoplasmosis in Chronically Infected and Subsequently Challenged Ewes

Author(s)

dos Santos, Thais Rabelo ; Magalhaes Faria, Gabriela da Silva ; Guerreiro, Bruna Martins ; Pereira da Silva dal Pietro, Nathalia Helena ; Zanetti Lopes, Welber Daniel ; da Silva, Helenara Machado ; Garcia, Joao Luis ; Rui Luvizotto, Maria Cecilia ; Saraiva Bresciani, Katia Denise ; da Costa, Alvimar Jose

• Document type: Journal article
• Source: PLoS One; v. 11, n. 10 OCT 27 2016.
• Web of Science Citations: 2

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 40(th) 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. (AU)

• FAPESP's process: 09/06173-9 - Experimental reinfection in pregnant ewes with Toxoplasma gondii
• Grantee: Alvimar José da Costa
• Support Opportunities: Regular Research Grants