Isolation of Toxoplasma gondii development mutants identifies a potential proteophosphogylcan that enhances cyst wall formation.

Within warm-blooded animals, Toxoplasma gondii switches from an actively replicating form called a tachyzoite into a slow growing encysted form called a bradyzoite. To uncover the genes involved in bradyzoite development, we screened over 8000 T. gondii insertional mutants by immunofluorescence microscopy.

Parasite stage-specific recognition of endogenous Toxoplasma gondii-derived CD8+ T cell epitopes.

Background: BALB/c mice control infection with the obligate intracellular parasite Toxoplasma gondii and develop a latent chronic infection in the brain, as do immunocompetent humans. Interferon-gamma-producing CD8+ T cells provide essential protection against T. gondii infection, but the epitopes recognized have so far remained elusive.

Increased efficiency of homologous recombination in Toxoplasma gondii dense granule protein 3 demonstrates that GRA3 is not necessary in cell culture but does contribute to virulence.

Toxoplasma gondii possesses unique secretory organelles, which synchronously release proteins during and after invasion. One of these organelles, the dense granules, secrete proteins after invasion which are thought to be important in development of the parasite throughout all stages of its life cycle. Dense granule protein 3 (GRA3) is a 30 kDa protein localized to the intravacuolar network and parasitophorous vacuole membrane (PVM).

Molecular subtyping and characterization of bovine and human Streptococcus agalactiae isolates.

Streptococcus agalactiae causes severe invasive disease in humans and mastitis in cattle. Temporally matched bovine milk isolates and clinical human invasive isolates (52 each) collected in New York State over 18 months were characterized by molecular subtyping and phenotypic methods to probe the interspecies transmission potential of this species. EcoRI ribotyping differentiated 17 ribotypes, and DNA sequencing of the housekeeping gene sodA and the putative virulence gene hylB differentiated 7 and 17 allelic types, respectively.