T.cruzi Flashcards
(30 cards)
Causes which disease?
Chagas disease
Is endemic to?
Latin America
Replicates in the?
Cytosol
Infects which cells?
Can infect various cell types
Has a particular tropism for skeletal muscle and cardiac muscle
Has a tropism for which cells?
Skeletal muscle, smooth muscle and cardiac muscle
Can be treated with?
Drugs
Spread by which vector?
Kissing bugs
Triatomine vector
What infective form enters humans?
Metacyclic trypomastigotes
When intracellular?
Amastigotes form
What forms in the midgut of the kissing bug?
Epimastigotes
Amastigotes replicate via?
Binary fission
Epimastigotes become trypomastigotes in?
In the hindgut of the triatomine bug
What are the two methods of cell entry?
Lysosome dependent
Lysosome independent
Lysosome dependent entry?
1) Cell wounding is elicited
2) Intracellular influx of Ca2+
3) Exocytosis of lysosomes, recruitment of lysosomes to the parasite attachment site is mediated by Ca2+
4) T.cruzi vacuole fusion with the lysosome at the attachment site
5) Lysosomal membrane is anchored to microtubules which creates a force for internalisation
Lysosome independent entry?
1) Formation of vacuole which is plasma membrane derived- plasma membrane derived invagination
2) Internalisation of the parasite
3) Fusion of the vacuole with endosomes and lysosomes occurs later on
Which form of entry is reversible?
Lysosome independent entry is reversible
Regardless of entry route what must occur for productive cell infection?
Fusion with the host lysosomal compartment is required for retention of the parasite within the host cell
When lysosome fusion is inhibited?
The parasite fails to be retained within the host cell
Why does the parasite exit the parasitophorous vacuole?
After fusion with the lysosome it is acidic and the parasite wants to enter the cytosol which is less acidic and has more abundant nutrients available
How does the parasite exit the parasitophorous vacuole?
Via haemolysin
Via trans-sialidases
Where does replication of amastigotes occur?
Replication of amastigotes occurs in the cytosol
What is the cell surface of T.cruzi like?
Covered in mucins and mucin like proteins
Covered in trans-sialidases
Trans-sialidases are attached via?
GPI
The trans-sialidases can be present?
Extracellularly in the blood
