W2- Phylum Sarcomastigophora. Subphylum Mastigophora Flashcards
What is Phylum Sarcomastigophora?
what are subphylums?
they are free living protozoans.
subphylums:
- Mastigophora/ flagellates–> move using flagella
- Sarcodina/ ameboa–> move by cytoplasmic protrusions called pseudopods
Genus Trypanosoma characteristics
has:
- a single nucleus (round/oval in centre of body),
- a kinetoplast (well developed mitochondrion DNA),
- a single flagella.
- affects humans and animals,
- mostly transmitted by insects.
- size= 14-33µm
- has an undulating membrane(trypomastigote)
What are trypanosomes?
where are the found?
- they are Extracellular hemoflagellates in connective tissue space.
In smear: between RBCs - found in peripheral blood, lymph nodes, spleen + cerebrospinal fluid
What is Trypanosoma Equiperdum?
cause?
It is an animal parasite causing dourine in horses. DOESN’T affect humans.
it is an extracellular parasite living in blood plasma. cell is elongated and spindle-shaped. it is a trypomostigote (kinetoplast is posterior to the nucleus).
Trypanosoma Equiperdum transmission
sexually transmitted in horses
Is Trypanosma Brucei intracellular or extracellular?
what does it cause?
an extracellular parasite, they are in-between RBCs - doesn’t enter cell.
infects humans and animals causing African trypanosomiasis (sleeping disease).
sleeping disturbances, abnormal reflexes, sensory disorders, untreated=death
Trypanosma Brucei transmission
latin name?
transmitted by vectors=tse-tse fly bite. (lat= Glossina)
Trypanosma Brucei forms
trypomastiogote in vertebrate host, epimastigote in the insect vector
What are the types of Trypanosma Brucei?
where are the the types found?
T.B Gambiense: takes years to act, chronic. found in C+ W Africa
T.B Rhodesience; acts in week, acute. found in S+E Africa.
Hemoflagellates morphology
- Amastigote:(Hum) rounded, no flagellum. seen as intracellular form in vertebrate host. Axosome- ant of cell. not mobile
- Promastigote:(Ins) K ant to N, near ant of cell. F at anterior of cell. no UM.
- Epimastigote:(Ins) K post of cell, its ant to N. F runs alongside the body as short undulating membrane then emerges from the ant end
- Trypomastigote:(Hum) spindle shaped w/ central N. Kineto post to N at post end of body. F runs alongside the entire length of the cell + forms a long UM before emerging as a free F from the ant end
Trypanosma Brucei Life cycle
- Tsetse fly injects metacyclic trypomastigotes
- meta..—> long slender trypomastigotes in blood. Reach body fluids
- multiply in fluids- binary fission
- trypomastigotes circulate in blood
- tsetse fly takes blood w/ trypomastigote
- go to midgut-procyclic trypomastigotes. multiply
midgut, leave as epimastigote - epimastogoes go salivary gland of vector.
Epimastigote—> metacyclic Trypomastigotes
Hosts of Trypanosma
Def Host: humans
Inter Host: insect vector (tse-tse or ‘kissing bugs’)
Is trypanosome Cruzi extracellular or intracellular? what does it cause? where?
its extracellular and intracellular parasite.
causes chagas disease
found in C&S America
How is trypanosome Cruzi transmitted/vector? when are they active
transmitted through bite of Triatomine bug (kissing bug)
they feed during the night, feces rubbed into bite wound
Morphology of trypanosome Cruzi
in human host: extracellular trypomastigote in blood AND intracellular amastigotes in tissues
in insect vector: epimastigote
Life cycle of trypanosome Cruzi
- Infected Triatomine bug passes metacyclic trypomastigote in faeces or bite wound
- Metacyclic trypomastigote penetrate through cells and becomes amastigote- loose flagellum
- Amastigote replicate in cell by binary fission and infect cell
- Amastigote–> trypomastigote cell ruptures releasing the trypomastigote into bloodstream
- Triatomine bugs ingest trypomastigotes
- Differentiate to epimastigote in midgut and multiply in midgut.
- Metacyclic trypomastigotes in hind gut
Leishmania Donovani hosts/vector
def host: human,dog &mammals vector: female sandfly (Phlebotominae)
Is Leishmania intracellular or extracellular?
its intracellular (amastigote) parasite in host. its extracellular (promastigote) in sandfly vector