Assistant professor (July 2000 to date)
Office: Essex Hall 275-3
Phone: 253-3000 ext 3550
Toxoplasma gondii, a pathogenic member of the phylum Apicomplexa, is an obligatory intracellular parasite of mammals and birds. Particularly in Canada, the outbreak of T. gondii infection was reported to be associated with the contaminated municipal water supply in British Columbia in 1995. It has been estimated that approximately one-third of North-Americans are infected. Three infectious stages are detected in this protozoan parasite; tachyzoites (asexual), bradyzoites (in tissue cysts, asexual) and sporozoites (in oocysts, sexual reproduction only in feline). Human infection often occurs by ingestion of contaminated food or undercooked meat containing tissue cysts. Neonate or acute infections in pregnant women can give rise to blindness, mental retardation and hydrocephaly in children. In healthy adults, the infections are usually asymptomatic because an immune response or an antibiotic treatment quickly eliminates the parasites. However some parasites can escape the immune response and chemotherapy by differentiating and residing within a cyst structure that will remain in the brain and other organs during the lifetime of the infected host. In immuno-compromised hosts (i.e. AIDS patients), the development of fatal Toxoplasma encephalitis is due to the transition of the resting bradyzoites to the active and rapidly replicating tachyzoites. It is likely that in chronic toxoplasmosis bradyzoites, in tissue cysts, regularly transform to tachyzoites and that these active forms are removed or sequestered by the immune system. The differentiation between bradyzoites and tachyzoites is therefore a crucial event in the life cycle of T. gondii in its intermediate hosts as well as a determining step for human health, especially in AIDS patients.
MSc and PhD student positions are currently available.
Prospective postdocs should contact us directly.