Protozoa Flashcards
What do protozoa eat?
Bacteria & fungi
What are some cellular constituents of protozoa?
Nucleus (eukaryotic), 1 mitochondrion (not always), apicoplast (associated with mitochondrion), flagella, cilia
How do protozoa reproduce?
Asexually via mitosis/budding
Some can produce sexually - produce gametocytes
How do some protozoa escape immune cells?
Form cysts
What causes amoebiasis? What does it do to the body?
Entamoeba histolytica - found in poorly treated water - cause damage to intestine - diarrhoea & cramps
What causes leishmaniasis?
Leishmania - sandfly bite
What causes malaria?
Plasmodium species - bites from female Anopheles mosquito
P. falciparum, P. vivax, P. ovale, P. malariae, & P. knowlesi
What is the common cause of disease?
Plasmodium vivax
What is the most deadly cause of malaria & why?
Plasmodium falciparum - blood clots (all plasmodium species) - uniqueness cerebrally clots & swelling
What gene prevents malaria infection?
1 allele for sickle cell anaemia
In what form is plasmodium introduced into the body?
Sporozoites
In what form is Plasmodium found in hepatocytes?
Merozoites
In what form is Plasmodium found in RBC
Trophozoite - ring like structure
In what form does Plasmodium get taken back up by an uninfected female Anopheles mosquito?
Gametocytes
Life cycle of Plasmodium
1)Female Anopheles mosquito bites human - secretes saliva to prevent clotting - introduces Plasmodium in the form of sporozoites
2)Travel to liver & attack hepatocytes - reproduce asexually - lyse hepatocyte & released as merozoites
3)Merozoites attack RBC & form ring like structure called trophozoite
4)Reproduce asexually & form merozoites - lyse RBC releasing merozoites - repeat 3) & 4)
OR
4)Form gametocyte, taken up by uninfected female Anopheles mosquito - fuse to form zygote
What is the definite host of Plasmodium?
Female Anopheles mosquito
Diagnosis of malaria
Blood film - Giemsa stain - headphone-like inclusion (trophozoite)
Symptoms of malaria
Intermittent fevers, anaemia, splenomegaly, fever, nausea, vomiting, rigoris, headache, coma
What was previously used to treat malaria?
Tonic water - quinine
What attracts mosquitoes?
Body odour, microbiome, & temperature (pregnant women)
What causes Chagas disease?
Trypanosoma cruzi - bite from Reduviid bugs/kissing bugs/vampire bugs - South & Central America
What causes babesiosis?
Babesia microti from deer ticks
What causes Toxoplasmosis?
Toxoplasma gondii - cat faeces
What is Babesiosis?
Babesia microti infects RBC - replicates into 4 - Maltese Cross formation seen in blood film - fever & haemolytic anaemia
What is cryptosporidium?
Thick-walled oocyte in water (not UV treated - run-off from livestock) - grows in intestine - released into the environment as oocytes
What are the definite hosts of Toxoplasma gondii?
Cats - found in faeces
Human impact of toxoplasmosis?
30-50% humans in contact - dangerous in immunocompromised & pregnant women
Impact of toxoplasmosis on mice?
Mice eat cat faeces - lose fear of cats - cat eats mice
