Intestinal protozoa

Question 1

Describe entamoeba histolytica

Answer 1

Diarrhea causing protozoa, gets ingested through food or water. Enters body in cyst form, trophozoite will crawl to the colon and eat bacteria

Question 2

Describe the cyst shell of entamoeba histolytica

Answer 2

It contains sugar, the same as insect shell, and proteins

Question 3

What virulence factors do entamoeba histolytica have?

Answer 3

Cysteine proteases, amoeba porins, LPH, GalNAc lectin, peroxidoxin

Question 4

What does cysteine proteases do?

Answer 4

Breaks down mucus in the large intestine to come in closer contact to the epithelium

Question 5

What does GalNAc lectin do?

Answer 5

Bind to GalNAc on epithelial cell surface so it can sit on the cell. Can also induce apoptosis

Question 6

What does amoeba porins do?

Answer 6

A toxin that destroy cells

Question 7

What characterizes immune reaction towards entamoeba histolytica?

Answer 7

High level of IgA levels against the surface lectins when it hasnt entered tissue yet; when it has entered tissue theres a strong inflammation

Question 8

Describe cryptosporidium parvum/hominis?

Answer 8

Diarrhea causing protozoa, gets ingested through food or water. Enters body in oocyst form, kind of complicated life cycle. Sits in a little bubble structure on the host cell, can do both asexual and sexual replication. Sits in the small intestine.

Question 9

What is the major cause of diarrhea in children?

Answer 9

cryptosporidium

Question 10

How do you diagnose cryptosporidium?

Answer 10

Either with microscope, looking after oocysts in feces. Can be hard to see. Can do acid fast stain to see them easier. Can also do antigen detection or PCR.

Question 11

How does the immune system respond to cryptosporidium?

Answer 11

IFN-gamma is a big part of the immune response; the infected cells create an inflammasome which in turn triggers the release of IL-18 which triggers IFN-gamma.

Question 12

Describe giardia

Answer 12

Sits outside the cells in the small intestine, causes watery diarrhea. Suppresses inflammation, increases gut permeability. Stops body from nutrient uptake

Question 13

Describe the giardia life cycle?

Answer 13

One cyst contains four giardia parasites

Question 14

What symptoms does entamoeba give rise to?

Answer 14

Dysentery (bloody diarrhea) and liver abscesses