Infection of non-adherent TG180 murine sarcoma cells with Toxoplasma gondii was compared, at the ultrastructural level, in both in vivo and in vitro conditions. Suspensions of 3.0 x 10(6) TG180 cells infected in vitro with 1.0 x 10(6) parasites of the RH strain were harvested between the first and 6th day post-infection and processed for transmission electron microscopy. In vivo infection was m...

The virulent RH strain of Toxoplasma gondii is acutely lethal in mice and fails to establish chronic infection. Vaccination of BALB/c mice with a soluble tachyzoite antigen preparation, STAg, in combination with the immunostimulatory cytokine interleukin-12 results in partial protection against RH lethal challenge. Nevertheless, brain tissue obtained from surviving, vaccinated mice as late as 1...

Toxoplasma gondii is a zoonotic protozoa of economic significance in livestock. Infected livestock meat and products act as a source of T. gondii infection in humans. Current drugs against T. gondii are limited by hypersensitivity and toxicity, and are not effective against the encysted bradyzoite stage of T. gondii. Thus, there is urgent need for safe and effective therapeutic agents against T...

The disease bovine besnoitiosis is responsible for severe economic losses caused by the protozoan Besnoitia besnoiti. The identity of the definitive host (DH) of this parasite has yet to be determined, although it is presumed to be a carnivore. With the aim of advancing in the identification of B. besnoiti DH, a necessary step in implementing control strategies, the contact rate of 205 free-roa...

Sarcocystis is an obligatory intracellular protozoan parasite which can infect humans and animals. Sheep are intermediate hosts of four Sarcocystis species: Sarcocystis tenella, Sarcocystis gigantea, Sarcocystis arieticanis, and Sarcocystis medusiformision. The purpose of the study was to determine the molecular identification of the macroscopic and microscopic cysts of Sarcocystis in sh...

Parasite-specific antibody responses were detected using an indirect fluorescent antibody (IFA) test in cattle that were naturally or experimentally infected with Neospora parasites. The test was developed using Neospora tachyzoites isolated from an aborted bovine fetus and grown in bovine cell cultures (isolate BPA1). In all cases, infections were confirmed by the identification of Neospora ta...

Toxoplasma gondii is an important opportunistic pathogen in immunocompromised individuals. Successful propagation in an infected host by this obligate intracellular parasite depends on its ability to enter and exit host cells. Egress from the cell can be artificially induced by causing fluxes of calcium within the parasite with the use of calcium ionophores. While this ionophore-induced egress ...

The outcome of infectious diseases in vertebrates is under genetic control at least to some extent. In swine, e.g., marked differences in resistance/susceptibility to Sarcocystis miescheriana have been shown between Chinese Meishan and European Pietrain pigs, and these differences are associated with high heritabilities. A first step toward the identification of genes and polymorphisms causal f...