Diarrheagenic Protozoans Flashcards
What will you see under the microscope when you look at a giardia trophozoite?
2 nuclei
Flagellae
~~👽~~
What are the 2 forms of cryptosporidium and which one infects you?
Oocyst- infects you.
Sporozoites- active form
How do you diagnose entamoeba histolytica?
Stool sample- cysts AND trophozoites
CT/MRI- may reveal abscesses
ELISA- works great if you have money
PCR- great but you have to pay a lot and these people are in tropical developing countries
What is the life cycle of entamoeba histolytica?
- You eat a cyst
- Cyst degrades in colon
- Trophozoites hang out in colon
- Some may invade intestines and gain access to the bloodstream to go where ever they want
- Some will turn into cysts and you poop out cysts and trophozoites
Who usually gets cryptosporidiosis?
Children
What will blastocystis hominis look like under a microscope?
Large central vacuole
Multiple nuclei around the rim
What are the 2 morphological stages of giardia?
Trophozoite- exists in the small intestine and eats mucus secretions. Has 2 nuclei
Cyst- passed into the environment
What are the 2 types of oocysts that cryptosporidium forms in your intestines?
Thin walled- asexual, reinfect you
Thick walled- sexual, get pooped out into environment
Will giardiasis cause bloody diarrhea?
No, just watery
Which may lead to a B12 deficiency
Can you get giardiasis from doing sex acts
Yes
Will cryptosporidiosis go away on its own?
Yes, if you are healthy
Very serious, prolonged diarrhea in AIDS patients
Can you get giardiasis from dogs and beavers?
Yes
How many nuclei are in the giardia cyst?
4.
Each cyst will make 2 trophozoites
Do giardia have flagellae?
Yes (which means they have an H antigen)
How many nuclei are in the cyst form of entamoeba histolytica?
4.
4 trophozoites from 1 cyst
Will amoebiasis cause bloody diarrhea?
YES
What is the lifecycle of cryptosporidium?
- You eat the oocyst and it releases 4 sporozoites
- In your intestines, they are ingested into a parasitophorous vacuole on your epithelial cells
- Inside the epithelial cell, they do sexual and asexual reproduction to form more oocysts
- THIN walled oocysts (asexual) reinfect you
- THICK walled oocysts (sexual) get pooped out
What are some of the virulence factors that entamoeba histolytica has?
Lectin-assists in adhesion to host cells
Phospholipases- rips through cell membranes
Amoebapore- pokes holes into host cells and lyses them
Cysteine proteases- degrade mucus, antibodies, complement, and cellular matrix
What do you need to do to prevent amoebiasis?
You need to purify your water with iodine or by boiling it.
CHLORINE DOES NOT KILL CYSTS
🏊♂️
What will Balantidium coli look like under the microscope?
BIG MACRONUCLEUS
Cilia
How would you tell apart the oocysts of cryptosporidium vs cyclospora?
Cyclospora oocysts are much BIGGER and they AUTOFLUROESCE****
What are the 3 things that you should know about the cyclospora oocyst?
BIG AND ROUND
Acid fast
Autofluorescent
Will chlorine kill cyclospora oocysts?
No
Do we see a lot of long term effects from giardiasis?
No. It is rarely associated with mortality except in extreme dehydration cases
What is the lifecycle of giardia lamblia?
- You eat the cyst from food/water
- Excystation in stomach acid (cyst cover degrades)
- Trophozoites go to small intestine and divide and hang out
- When they get to the large intestine, the change in environment tells them to make cysts again
- You poop out the cysts
What causes cryptosporidiosis?
At least 15 different species: Cryptosporidium hominis (humans)
Cryptosporidium parvum (cows and humans)
How do you test for giardia?
You have to look at stool samples, but you might have to look at several as it can be very difficult to detect.
There is an ELISA test to test for the antigen, but it causes a lot of false positives, because if a human has EVER had giardia, it will come back positive.
What causes cyclosporiasis?
Cyclospora cayetanensis
Will cyclosporiasis cause bloody diarrhea?
No
Which organism forms a parasitophorous vacuole at the edge of your intestinal epithelial cells?
Cryptosporidium
Under microscope, they look like little studs lining the intestinal cells
Which Protozoa causes amoebiasis?
Entamoeba histolytica
How many nuclei does the trophozoite form of entamoeba histolytica have? Does it have flagellae?
1 nucleus
No flagellae
How many sporozoites does each oocyte of cryptosporidium contain?
4
Which Protozoa can cause colitis and liver abscesses?
Entamoeba histolytica
What is an insane thing that can happen to you if you have amoebiasis?
ULCERS. ON YOUR SKIN. Or on your LIVER
Causes right upper quadrant pain too.
Are the oocysts of cyclospora infectious right after you poop them out?
No. They MUST sporulate in the environment, which takes a few days.
Very little reinfection
Where does balantidium coli come from and what does it do to you?
Comes from pigs
Can perforate your gut
If you have a LONG term infection of giardia, what can happen?
Intestinal villi may flatten, causing malabsorption
Amounts of tissue damage from giardia is usually VERY minor
How can you get cyclosporiasis?
Water and imported fresh fruits and vegetables from Latin America that are contaminated with oocysts
In the stool sample of someone with amoebiasis (entamoeba histolytica), what will you see?
Cysts AND trophozoites
You May also see RBCs inside them, since thats what they eat
What is the most common intestinal parasite in the world?
Giardia lamblia
What will you see in the stool sample of someone with cryptosporidiosis?
Round Oocysts* that are immunofluroescent**** (NOT sporozoites, and NOT autofluorescent)
Will chlorine affect cryptosporidium?
NO, this is a disease that is prevalent in swimmers. ALSO you can get infected from Cow poop!
🐄💩🏊♀️
What causes giardia?
Giardia lamblia aka giardia intestinalis
Can amoebiasis affect areas of your body other than your intestines?
YES they can disseminate and get anywhere in the body