protozoa Flashcards
How can you determine the difference between plasmodium vivax and malariae?
After mature ring form vivax becomes a thropozoite and has 12-24 merozoites.
Malariae in contrast a band form and only 6-12 merozoites.
What is the insect vector of leishmania?
Phlebotomus papatasii (sand fly)
Describe Giardia Lamblia structure
two nuclei, 8 flagella, adhesive disk
Definitive host of toxoplasma gondii?
felidae family (Cats)
What is the structure of Trypanosoma?
Flagellum, nucleus, blepharoplast + parabasal body = kinetoplast, undulating membrane
What is the structure of Trichomonas
Oval, pear shape, all similar structure but different sizes
4 flagella, undulating membrane, costa, nucleus, axostyle
( t.Vaginalis 15-30um, tenax 6-10um)
What is the name of the parasite that uses phlebotomiae as a vector?
Genus Leishmania (L. donovani, brasiliensis, tropica)
Latin name for kala-azar, black fever and dumdum fever
Visceral leishmaniasis
What is the latin name of Protozoa parasite transmitted by flies from genus glossina
Trypanosoma brucei gambiense & rhodesiense
Intestinal protozoa belong to which phylum?
Phylum Sarcomastigophora, Subphylum Sarcodina
Write the name of parasite with undulating membrane which is transmitted by
bloodsucking insect
Trypanosoma Brucei
Vector for trypanosoma brucei
Glossina sp. (tse-tse fly)
What unicellular parasite can form a cyst
Toxoplasma gondii
Latin name for sleeping sickness and how are humans affected?
African trypanosomiasis, When tsetse fly (glossina) takes blood meal it injects
metacyclic trypomastigotes into the human bloodstream
Name 3 insect vectors that are infectious
Anopheles, Triatoma, Phlebotomus, Glossina
Life stages of a mosquito
Eggs, First larval stage, Second Larval stage, Third larval stage, Fourth larval stage, Pupal
stage, Adult
Form of plasmodium falciparum found in blood
Immature trophozoite (Ring form) and gametocytes
A parasite with an undulating membrane that infects liver
Trypanosoma cruzi
Name of disease for trichomonas tenax
No disease, but can worse preexisting periodontal disease
How can you detect plasmodium malariae and falciparum on blood sample
Plasmodium malariae: Merozoites invade only old erythrocytes, schizont is slightly smaller
than a normal erythrocyte, large ring form that forms a band form; merozoites are 6-12 and
in rosette
P. falciparum: The
erythrocytes are not enlarged, more than one plasmodium in a cell and ring stage is with
double chromatin dots. You can also see Maurer’s dots, has banana shaped gametocytes
Name a form of plasmodium falciparum found in blood
Rings and gametocytes
What causes sleeping sickness
Trypanosoma brucei, transmitted by Glossina (tse Tse fly)
Name a unicellular parasite which has a cyst
Taxoplasma gondii
How can trichomonas vaginales infect humans
Sexually
Write the latin name of a protozoan parasite with undulating membrane and
insect vector
Trypanosoma brucei
Which member of phylum Sarcomastigophora causes sleeping sickness? Write
its latin name and describe how it moves
trypanosoma brucei, moves by flagellum
Describe the erythrocytic schizogony of plasmodium viva
schizogony = when the merozoites invaded the red blood cells and undergo another asexual cycle.
During that stage the merozoites develop to form immature or ring stage trophozoites, which mature to trophozoites.
Then they develop into schizonts.
At the end of the cycle the RBC burst, releasing merozoites. They can either infect
another RBC or develop into gametocytes
Which parasite causes visceral leishmaniasis?
Leishmania donovani
Describe the life cycle of plasmodium vivax
Anopheles injects sporozoites into human during blood meal. Infect liver cells, mature into
schizonts, rupture and release merozoites. (Vivax also has a dormant stage (hypnozoites) in
liver). After the exo.erythocytic cycle the merozoites infect red blood cells (erythrocytic cycle)
and turn into ring stage trophozoites, that mature into schizonzs, rupture and release
merozoites. Then they differentiate into gametocytes. They are ingested by anopheles during
blood meal. In mosquitos stomach they form zygotes, which become motile ookinetes, which
invade midgut and develop into oocysts. They grow, rupture and release sporozoites, which
go to salivary glands. Get injected during next blood meal
Which member of phylum Sarcomastigophora causes dysentery? Write its latin name and
describe how it moves ?
Entamoeba histolytica
Moves by pseudopodia
Describe the differences between cysts, oocysts and sporocysts of toxoplasma gondii
Cysts: Bradyzoites form cysts mainly in brain, liver and muscles. If the prey gets ingested by
cat they release bradyzoites in stomach and intestine
Oocysts: Bradyzoites differentiate into gametocytes, they fuse, form a zygote that matures
into an oocyst
Sporocysts: If an oocysts is ingested it releases sporozoites that differentiate into tachyzoites
and invades tissue
Describe three ways for infection of human by toxoplasma gondii
Raw or undercooked meat containing cysts
ingesting water, soil or food contaminated with oocysts
Transmission from mother to fetus
Blood transfusions
Describe the life cycle of trypanosoma brucei gambiense and explain the way of infection
Tse Tse fly (glossina) takes blood meal on human or other mammal and injects metaclyclis
trypomastigotes into skin tissue. Parasite enters lymphatic system and bloodstream. They
become bloodstream trypomastigotes and are carried throughout the body and reach other
body fluids (eg lymph or spinal fluid). They replicate via binary fission. When another Tse Tse
fly takes blood meal it becomes infected with bloodstream trypomastigotes. They transform
in the fly’s midgut into procyclic trypomastigotes and multiply by binary fission, leave the
midgut and become epimastigotes. They reach fly’s salivary glands, continue
multiplication and transform to metaclyclic trypomastigotes.
Where does leishmania donovani live in the human body? Write the latin name of the insect
vector
Parasite migrates to the internal organs, eg liver, spleen and bone marrow.
Insect vector: Phlebotomus papatasii (sand fly)
T.Gondi what kind of reproduction?
Endogeny- cell division of 2 daughter cells in mother
Life cycle of T.Gondi?
1.intermediate hosts infected after injecting soil/water/plant material containing oocysts
2. cat gets infected after eating tissue cysts in rats/otheranimals
3. oocysts transform into tachyzoites after injestion and develop into tissue cyst bradyzoites
4. Bradyzoites realeased into s intestine + undergo schizogony
5. This forms merozoites + they enter other tissues outside the intestine + form tissue cysts in other organs in body
6. other merozoites transform into M+F gameteocyts + gameotogony begins (macrogamete fertilized my microgamete to form oocyst.
7. Oocyst mature (sporulation) in soil after excreation of host through feaces.
8. it has 8 sporozoites ( infestive stage)
9. they are injested by intermediate hosts + cycle repeats :(
Phylum Apicomplexa (sporoza) are all intracellular parasites. What special structure do they have?
Has apical complex on one of the poles
They are a group of cytoskeletal structures and membrane organelles
Involved in attachement ton host cell, penetration, rearrangemnt of organelles and parasite proliferation (rapid increase)
Consists of conoid, apical ring, rhoptries, micronemes and dense granules
Apicomplexa does both asexual and sexual reproduction by which processes?
Schizony-asexual by multiple mitotic divisions cells produced called merozoites
Gametogony- sexual by meisos forming gametes
sporogony- produces sporozoites by repeated mitotic divisions of zygote (infective stage)
Genus Plasmodium causes malaria. What do their cycles normally involve?
vector= female mosquito
During blood meal, the parasite is injected into host
in humans, the parasite multiplies in the liver
They enter bloodstream and infect red blood cells= malaria
Phylum sarcomastigophora has 2 subphyla. What are they and the differences?
Mastigophora- These have flagella for movement. some flagella connected to cell membrane by undulating membrane
Sarcodina- uses pseudopodia for movement
Why does T.Brucei need to stay in the blood when it can attack CNS?
So glossina fly can suck the blood and transmit disease
L.dovani disease, vector, host
Visceral Leishmaniasis
Plebotomine sandflies
hosts can be rodents or dog like carnivores
Entamoeba histolyica: Where does protozoa live, infective stage disease
Intestinal parasite
infective stage is cysts transmitted by contaminated water and food
disease= amebiasis
Phylum ciliophora are large cells that live in lakes, oceans, river etc. What are their 2 different nuclei?
small diploid micronucleus for reproduction
large polypoid macronucleus for cell regulation
Which is the only ciliate known to be parasite in humans?
Balantidium coli- also the largest
Apicomplexa has specific mitotic mechanisms. What are they?
Endodyogeny-2 daughter cells formed inside mother cell
Endoplygeny-multiple daughter cells formed inside mother
5 species of the Genus Plasmodium causes malaria. Name 3 of them.
Plasmodium vivax
Plasmodium falciparum
*main causes
Plasmodium malariae
Genus Leishmania has 2 forms. What are they?
amastigote (intracellular) form in vertabrae host
promastigote(extracellular) from in sandlfy vector
Life cycle of L.donovani
Sandlfy will inject promastigotes into host (by taking blood meal)
Leishmania is a intracellular parasite but has no mechanism to direclty infect host, MACROPHAGES engulf the promastigote
Transforms to amastigote to multiply in cells
Sandfly takes another meal ingesting the infected macrophages
Transforms to promastigotes and cycle continues
Genus Trichomonas: which are harmless and which are not
T.tenax (commensal)
T.homini (commensal)
T.vaginalis(parasite)
Giardia lamblia are parasites in small intestine. What is their infective stage?
CYSTS
In the lower part of the intestine, te trophozoite is turned into cysts
they pass out of faeces and 1 host can produce many cysts
Genus Entamoeba belongs to what subphylum?
Sarcodina
The members are either internal parasites or commensals in the gut
How does some protozoa divide by mitosis?
The micronucleus divides by mitosis
The macronucleus justs splits into 2
T. Brucei disease, vector, host
Sleeping sickness
vector is the glossina fly
host is african mammals
How does T.Cruzi cause disease ( life cycle baso)
Bug takes blood meal and trypomasrigate enters through faeces of insect
Inside the human cells they transform into AMASTIGOTES which are intracellular and can multiply in host cells
Then transforms back into trpomastigotes and enter bloodstream again
Bug bites again and trypomasrigotes in bug now
Turns into epimastigotes in bug midgut
Forms trypomastigotes then process continues :)
What is the only reservoir for trichomonas vaginalis
human genital tract
transmitted through sexual/genital contact
may be asymptomatic in male but inflammation of vagina, urethra and cervix for female
Does the Balantidium coli affect healthy people?
No, it is commensal in healthy individuals
But parasite affect people with malnutrition + compromised immune system, colon dysfunction
What type of reproduction does Balantidium coli do?
Asexual- Binary fission
Sexual- conjugation where haploid micronucleus exchanges
After pentration, Apicomplexa creates a parasitophorous vacuole to survive within host cells. What does this involve?
Proteins secreted by parasite causes host cell to relocate ER, Golgi and mito around the vacuole to provide energy+ molecules to parasite
Brief life cycle of Plasmodium
Female mosquito injects sporozoite(litch just refers to a form of the parasite) into human
Sporozoite travels to blood and takes up residence in hepatocytes (liver)
They mutiply asexually to form many merozoites. Many merozoites collectively known as shizont.
Merozoites released by hepatocytes (they ruptured) into bloodstream.
These merozoites begin invading RBCs and multiply within them to form more merozoites.The merozoite in the rbc will form into ring like structure then trophozoite
RBC will burst releasing more merozoite
Each time more merozoites form (asexually) and cause cell lysis, this causes chills, sweating, fever
Cycle continues until death due to depletion of RBCs.
OR the merozoite can form into the SEXUAL form of the parasite- GAMETOCYTES. Needs both f+m gametocytes within RBC. Dont do much in blood no lysis
These will only become infective once injected by another mosquito then that mosquito can release sporozoites to another host.
T.Gondi 2 types of hosts and its danger to?
definitive host: cats (it does sexual repro here)
intermediate host: human/mammals (does asexual repro here)
danger to those with weak immune system and pregnant women
Sexual reproduction in cillates and sporozoas. What types of sexual?
Conjugation- 2 organisms join and exchange nuclear material
Gametogony/syngamy- m+fem gametocytes form and zygote forms after fertilisation=sporozoites
Trypanosoma Cruzi: disease, vector, reservoir host
Chagas disease
triatoma (kissing bug)
Reservoir are humans or armadillos, rodents, racoons etc
Throughout South America
Life cycle of G.Lamblia
You ingest cysts
The trophozoite undergoes asexual replication
Cysts and trophozoites expelled in feces
Only cysts can survive outside host not trophozoite
cysts can contaminate food and water
process continues
Protozoa do asexual reproduction. What are the types?
Binary fission- parasite divides into 2 or more equal number of parasites
Multiple fission/Schizony- Nucleus undergoes several divisions merozoites
Endodyogeny-multiply by internal budding
What are the forms of the T. Brucei
Trypomastigote (infective stage for vertebral host)
Epimastigote (shorter undulating membrane)
Both extracellular
How does the T.Brucei cause disease and why
Lives in blood then attacks CNS and cerebral spinal fluid
Brain no immune cells so easy to attack
Brain has blood brain barrier but trypanosomes can get past this
They multiply in cerebral fluid and cause sleeping disease
Why is it hard to treat trypanosomes?
Antgentic varaibilty
Its hard for us to keep up making new antibodies as their surface protein constanlty changes
Give latin name of a protozoan parasite transmitted by cyst
Balatidium coli
(not T.gondii that is oocyst)
Write latin name of 2 extracellular parasites
trypanosoma cruzi
trichamonas vaginalis
trypanosoma brucei
2 ways Balantidium coli can reproduce
asexual-mitosis
sexual-conjugation where micronucleus exchanged
what are the forms of trypanosoma brucei gambiense
trypamastigote- metacylic and procyclic in host
epimastigote- in hindgut of glossina fly
which is the infective stage of plasmodium
sporozoites
descibe morphology of giardia lamblia
8 flagella
2 nuclei
adhesive disk
difference between intermediate host and definitive
asexual repo in intermediate
sexual repo in definitive
life cycle of plasmodium in the vector
Anopholes mosquito is the definitive host
Gametocytes form in mosquito after they take blood meal of host with merozoites in blood
male and female gametocytes fuse to form a zygote (sexual)
zygote develops into oocyst.
oocyst undergoes sporogony and forms sporozoites in salivary gland which will infect human when blood meal taken
morphology of the 2 forms of leishmania
promastigote: elongated, nucleus, terminal kinetoplast and flagellum
amastigotes: rounded spherical shape with no flagella. Has nucleus and kinetoplast
morphology of trichomonas vaginalis
axostyle
flagella that forms undulating membrane
what are the 2 forms of genus Entamoeba
trophozoite (also giardia lamblia has this form fyi)
cysts
Balantidiu coli, toxoplasma gondii, Entamoeba histolytica
and giardia lamblia produces cysts
what are the differences
balantidium coli- only parasitic CILLATE. micro and macro nucleus (sexual)
toxoplasma gondii- APICOMPLEXA. cysts, oocysts, sporocysts (tachyzoites, bradyzoites)
entamoeba histolytica- subphylum SARCODINA
giardia lamblia- subphylum MASTIGOPHORA
2 parasites in phylum apicomplexa
toxoplasma gondii
plasmodium
