W3&4- Subphylum Sarcodina, Phylum Ciliophora, Phylum Apicomplexa Flashcards
Where is Entamoeba histolytica found?
In lrg intestine (cecum + colon)
How do Entamoeba histolytica move?
they are in the subphylum sarcodina, they move using temporary cytoplasmic extensions called pseudopodia.
NO mitochondrion
Entamoeba histolytica forms?
2 forms:
1) trophozoite
2) cyst
Entamoeba histolytica life cycle
- infection occurs by ingestion of mature cysts in f/w contaminated with feces
- Excystation in small intestine, trophoziotes are released. migrate to the lrg intestine
- Trophozoites they invade intestinal mucosa and use bloodstream to infect site (liver, brain, lungs). Trophozoites multiply by binary fission+produce cysts, which are both passed in feces
- Outside body, tropoziotes can’t survive, cysts can as they have dense wall to protect them. so cysts are responsible for transmission.
Entamoeba histolytica trophozoite morphology.
size=20-30 µm
they are anaerobic, move using pseudopods.
may be observed with ingested red blood cells
Nucleus contains central karyosome and fine peripheral chromatin.
Entamoeba histolytica cyst morphology
size=10-20 μm
spherical in shape.
- immature cysts=1 or 2 nuclei,
- mature cyst=4 nucleus w/ karyosome
Entamoeba histolytica infective form
Mature cyst w/ 4 nucleus
Entamoeba histolytica transmission
F/w contaminated w/ cysts
fecal-oral
What does Entamoeba histolytica cause?
Causes amoebiasis
Is Entamoeba histolytica intracellular or extracellular?
Intracellular
What does Balantidium coli cause?
length of cell?
Causes Balantidiasis.
lrg cells reaching 2mm
Where is Balantidium coli found?
In cecum or colon of humans/pigs
Is Balantidium coli intracellular or extracellular?
intracellular
Balantidium coli transmission
ingestion of f/w contaminated with feces containing cysts
Balantidium coli life cycle
- cyst through ingestion of f/w contaminated w/ feces
- after ingestion, excystation occurs in small intestine. Trophozoite colonise lrg intestine
- Trophezoide resides in lrg intestine lumen + appendix. Replicate by binary fission and conjugation may occur – type of a reproduction
- encystation of trophozoite occurs producing infective cyst. Some trophozoites invade wall of colon and multiply. Some return to lumen and disintegrate. Mature cyst passed with faeces
Balantidium coli infective form
cyst
Balantidium coli forms
has 2 forms:
1) trophozoite
2) cyst
Balantidium coli host
natural host - pig
accidental host- humans
Pigs are its reservoir hosts, and humans become infected through direct or indirect contact with pigs.
Balantidium coli trophozoite morphology
size=60- 70 μm
large ovoid cell.
- ant end=narrow, there is a groove(peristome) which leads to mouth (cytostome)
- post end= broad, there is an anal pore(cytopyge)
2 nucleus:
1)macronucleus- lrg kidney shaped. general cell regulation
2)micronucleus- for reproduction (genetic)
- 2 translucent vacuoles- digestion+contractile
Balantidium coli cyst morphology
spherical. surrounded by thick cyst wall.
macronucleus and vacuoles can be seen.
What phylum Balantidium coli in? what is its characteristic?
Phylum Ciliophora(Ciliates) they have cilia for movement+feeding.
reproduction in ciliates?
- binary fission (asexual)
- autogamy (self- fertilisation-nuclei fuse)
- conjugation- exchange of genetic materials through a cytoplasmic bridge. sexual process, cells exchange haploid nuclei instead of fusing.
1) meiosis -produces haploid nuclei
2) exchange haploid nuclei
3) finish w/ new combination of genes
Where is Toxoplasma gondii found?
SI and in organs eg brain, eye, heart, muslces
Is Toxoplasma gondii intracellular or extracellular?
Intracellular, uses warm-blooded animals as host
Toxoplasma gondii transmission
- raw/undercooked meat containing cyst
- ingesting f/w contaminated w/ oocysts(cat feces)
- transmission from mother to foetus,
- blood transfusion, organ transplant
Toxoplasma gondii host
Def host: cats
inter host: humans
What does Toxoplasma gondii cause?
Causes toxoplasmosis
Toxoplasma gondii forms
3 forms:
1) trachyzoite (rapid growth +reproduction),
2) bradyzoite (slower reproduction, in tissue cysts-muscle+brain)
3) sporozoites (in oocytes)
Toxoplasma gondii infective form
sporulated oocysts
Toxoplasma gondii life cycle
- unsporulated oocyst shed on cats feaces. Oocysts sporulate and become infective. inter host(humans)– ingest material with oocysts
- Oocysts–>trachyzoites after ingestion. they invade and multiply inside any cell. and releases more trachyzoites which develop into bradyzoite which forms cysts mainly in brain, liver and muscle tissue
- Cats are infected after consuming intermediate host with cyst. They can also be affected directly by ingestion of sporulated oocysts
Toxoplasma gondii trachyzoites morphology
3-7μm
they are cresent shaped, one end pointed(apical complex), the other is rounded.
long, elongated & thin
What phylum is Toxoplasma gondii from?
what are its characteristics?
Phylum Apicomplexa (Sporota) has a apical complex which allows host attachment and cell penetration. do sexual and asexual repro (endodyogeny)
Toxoplasma gondii bradyzoites morphology
Cyst= round. they remain in tissue
Toxoplasma gondii oocysts morphology
only develop in intestine of def host(cats).
oval shape, has a thick resistant wall.
formed by sexual repro(gametogeny). cats shed oocyst in feces, they are only infective when sporulated 1->2->4. oocyst lives in soil and is ingested which releases sporozoites in intestine.
How does Toxoplasma gondii reproduce?
Schizogony- asexual reproduction
Gametogeny- sexual (gamete fuse–> zygote) this undergoes sporogony. occurs in cats intestinal cells.
endodyogeny- asexual repro, internal budding, 2 daughter cells in mother cell
Toxoplasma gondii oocysts morphology
Only develop in intestine of def host(cats).
oval shape, has a thick resistant wall.
formed by sexual repro(gametogeny). cats shed oocyst in feces, they are only infective when sporulated 1->2->4. oocyst lives in soil and is ingested which releases sporozoites in intestine.
what is Entamoeba Dispar?
found?
forms?
non pathogenic,
found in lrg intestine.
trophozoites + cyst forms
Where is Entamoeba gingivalis found?
transmission?
between pockets near base of teeth
direct transmission by kissing, sharing utensils.
What is Paramecium caudatum?
In phylum Ciliophora.
length= 0.33 mm
covered with minute hair-like organelles called cilia- used in locomotion and feeding.
NOT PARASITE
Characteristics of genus plasmodium
- they reproduce sexually in female mosquito-Anopheles
- they have a apical complex to penetrate though cells
How does Plasmodium reproduce?
schizogony= asexual repro, type of mitosis. occurs is RBC and liver cells.
products of schizogony =merozoites
Where is Plasmodium found?
they are found in liver cell
in blood smear- they are inside RBCs
Plasmodium Host
vector+def host=female anopheles
inter host= vertebrates-humans(in liver+erythrocytes)
Plasmodium infective stage
sporozoites injected during blood meal
Plasmodium life cycle
- infected female anopheles inject sporozite(infective) from salivary gland.
- sporozoites travel via blood stream+ invade liver cells (hepatocytes).
- in liver they multiply asexually by Schizogony = producing many merizoites.(schizont contains them) they’re produced in liver+released into blood via vesicles=merizomes. liver cell burst releasing them into blood stream.
- merozites enter RBC by apicomplexan invasion. it differentiation into ring trophozoites+ multiplies (many merizoites) .
- RBC ruptured by merozoites. cycle repeats, more RBS are burst. After few cycles They differentiate into sexual forms. Male/female gametocytes
- Gametocytes are ingested by female mosquito. Parasite multiplies in mosquito by sporogonic cycle.they become mature
- In stomach of mosquito, male gamete penetrate female gamete creating zygote. zygotes invade midgut and develop as oocysts.
- Oocysts grow,rupure and releases sporozoites which go to mosquitos salivary gland. Then sporozoites go into human cycle restarts…
Are Plasmodium intracellular or intracellular?
intracellular
What does Plasmodium Vivax cause? MOST COMMON
what is the other name?why?
causes viviax malaria = tertian malaria.
called this because RBC schizogony lasts 48hrs+ fever occurs every 3rd day
How to distinguish Plasmodium Vivax?
- has a trophozoite ring stage.
- schizont has 12-24 merozoites
- infected erythrocytes= enlarged, have red Schüffner’s dots on the surface.
What does Plasmodium malariae cause?
causes quartan malaria
called this because RBC schizogony lasts 72hrs + fever on every 4th day
How to distinguish Plasmodium Malariae?
- band-like structure in the developing trophozoite,
- rosette form of the schizont (6-12 merozoites)
What does Plasmodium flaciparum cause? MOST SEVERE
causes falciparum malaria= tropical malaria
infects both mature and immature RBCs
continuous fever
complication= cerebral malaria-coma
How to distinguish Plasmodium Flaciparum?
Gametocytes are cresent shaped.
12-16 merozoites
RBC not enlarged, has “Maurer’s dots”(red)
what does plasmodium cause fever?
due to rupture of infected RBC
why is Plasmodium flaciparum most severe?
severe malaria= it multiples rapidly in the blood, and can cause severe blood loss (anemia).
The destruction of red blood cells by the malaria parasite can cause severe anaemia.
how is cerebral malaria caused?
Cytoadherence=erythrocytes are
prone to stick to blood vessel walls due to membrane changes.
• Obstructed circulation in organs, including brain (cerebral malaria).=coma
