Sarcocystidae in wild birds of southeastern Brazil.

This study aimed to identify members of the Sarcocystidae family in naturally infected wild birds at a rescue center in the state of Minas Gerais, southeastern Brazil. The heart and brain of 44 wild birds were evaluated by bioassay in mice to detect T. gondii, and extracted DNA was used for nested PCR of the 18S ribosomal DNA gene to detect members of the Sarcocystidae family.

Toxoplasma gondii: Cytokine responses in mice reinfected with atypical strains.

This study aimed to elucidate the cellular immune response against Toxoplasma gondii in chronically infected mice reinfected with different strains of the parasite to elucidate the immunological basis for chronicity or virulence and to uncover the involvement of genes that encode virulence proteins and modulate the immune response. BALB/c mice were infected by oral gavage with non-virulent D8 strain and challenged 45 days post-infection with virulent EGS or CH3 strains. Cytokine measurement was performed 2 days post-challenge in cell extracts of the small intestine and 2, 7, and 14 days post-challenge in serum.

Tissue dissemination and humoral response after experimental reinfection with atypical Toxoplasma gondii strains obtained from congenital human toxoplasmosis in Brazil.

The paradigm that Toxoplasma gondii infection generates sterilizing protective immunity was broken by case studies in which reinfections were observed in immunocompetent pregnant women in the chronic phase of toxoplasmosis. Since then, several murine models have suggested that immunoprotection against a previous T. gondii infection may be violated after reinfection with strains of different genotypes.

Toxoplasma gondii: isolation, biological and molecular characterisation of samples from free-range Gallus gallus domesticus from countryside Southeast Brazil.

Toxoplasma gondii presents a high prevalence worldwide, infecting several animals. Felines are considered the definitive hosts and among the intermediate hosts we highlight mammals and birds. The man can become infected by ingesting tissue cysts present in birds and mammals.

Kinetics of parasite distribution after reinfection with genetically distinct strains of Toxoplasma gondii.

Recent data shows that prior infection by Toxoplasma gondii does not protect the host from subsequent reinfection even after the development of immunological memory. Although animal models for T. gondii reinfection were proposed after cases of natural human reinfection were described, little is known about the events that occur immediately after challenge.