Toxoplasma gondii Flashcards
Toxoplasma classification
- phylum Apicomplexa
- Coccidian
Morphological forms (extraintestinal)
- Trophozoites (tachyzoites and bradyzoites; fast and slow-growing)
- crescentic - Cyst
- thick wall
- circular
- beware of pseudocysts !
- both asexual multiplication
- both extraintestinal
Intestinal form
- in CATS ONLY
- 2 sporocysts containing 4 sporozoites each = 8
- sexual cycle (gamogony) in jejunal epithelium
Intracellular form only invades __ cells. How ?
Intracellular form only invades NUCLEATED cells:
- apical complex/ drill-like conoid
- once inside host cell, parasitophosphorous vacuole protects parasite
Disease phases
- Early (acute):
- tachyzoites invade cells
- cell destruction/ necrosis = inflammation - Late (chronic):
- bradyzoites/ tissue cysts
- latency/ immunological evasion
- hypersensitivity
How does Toxoplasma Gondii affect the brain ?
infects directly = increases dopamine synthesis = risky behaviour:
- aggression in women, impulsivity in men, promiscuity in both
- homicide rates, suicide, traffic accidents
- T. gondii and schizophrenia
Common clinical presentation of Toxoplamsa gondii
Acute: asymptomatic (90%)
- lymphadenopathy
- flu-like symptoms
- more rarely, CNS and eye involvement
Chronic: asymptomatic (100%)
How is ocular toxoplasmosis detected ?
Eye examination:
- scarring and hemorrhage
Newborn is at risk of T. Gondii infection from the mother __ pregnancy/ conception
Newborn is at risk of T. Gondii infection from the mother AFTER pregnancy/ conception
- If mother is already infected before, they will have built enough immunity to protect placenta
Newborn is at risk of T. Gondii infection from the mother __ pregnancy/ conception
Newborn is at risk of T. Gondii infection from the mother AFTER pregnancy/ conception
- If mother is already infected before, they will have built enough immunity to protect placenta
Vector for Toxoplasma gondii
Cat feces
