Intestinal Protozoan Microbiology

  1. What is the most common cause of chronic diarrhea in travelers?
  2. What is the leading cause of death from parasite worldwide?
    Entamoeba histolytica
  3. Which is the most common cause of recreational water-related disease outbreak in the US?
  4. Cellularity of protozoa?
    Unicellular eukaryotes
  5. How do protozoans reproduce?
    By binary fission
  6. Where do Trophozoites replicate?
    Inside of us
  7. True/false: trophozoites are the infective stage and they replicate in the outside environment
    False; they are not the infective stage and they replicate inside of us
  8. True/false: trophozoites have cytoplasmic membrane in its outermost layer
  9. When do trophozites encyst?
    They become cysts (encyst) as they move down to the colon
  10. True/false: Cysts are non mobile and do not replicate
    True. They are usually passed in feces
  11. When do cysts excyst?
    They excyst in small intestines and become trophozoites
  12. Which part of the fecal-oral life cycle does the protozoa feed, move and replicate? Which part of the life cycle is it passed in the feces, resistant and infective form.
    • Trophozoite- feeding, motile, replicate
    • Cyst- passed in feces, nonmotile, resistant and infective
  13. Which of the intestinal protozoan is it an obligate intracellular parasite?
  14. Which of the intestinal protozoan has flagella?
    Giardia duodenalis
  15. Which of the intestinal protozoan is an ameba?
    Entamoeba histolytica
  16. Cholera-like (mild to fulminant) diarrhea is seen in______
    Cryptosporidiosis (esp in immunocompromised)
  17. Bloody, mucousy diarrhea, flask shaped ulcers and liver abscesses is seen in_____
  18. Greasy and fatty, foul-smelling and watery diarrhea is seen in ______
  19. True/false: benefits of diarrhea in host and the microbe is essentially the same
    True; get the microbes out so it can spread
  20. What is the predominant cause of travelers diarrhea?
    E coli
  21. How are protozoans transmitted?
  22. True/false: protozoans can be transmitted through anal-oral sex
  23. Cysts excyst in ______, to become ________. Trophozoites encyst in _______, to become _______.
    • Small intestine; trophozoite (replicating form)
    • Colon; cysts (infective form)
  24. How are protozoans diagnosed?
    • microscopic analysis of cysts in stool
    • ELISA (fecal immunoassays)
  25. Which intestinal protozoans have shared reservoirs in mammals, fish, amphibians, reptiles, birds?
    • Giardia
    • Cryptosporidium
  26. True/false: Entamoeba has reservoir in fish, amphibians, reptile and birds
    False; they have a human reservoir. The other two have the common shared reservoris in fish, amphibian, reptile and birds etc.
  27. Which intestinal protozoan has disease stage that penetrate human colon with a secondary infection of liver?
    Entamoeba histolytica
  28. Which intestinal protozoan has disease stage in duodenum/ jejunum?
  29. Which intestinal protozoan has disease stage that multiply intracellularly in mucosal epithelial cells in the small intestines?
  30. Which one ingests RBC, bacteria as their virulence factor?
    Entamoeba histolytica
  31. Which one has pore-forming protein cytotoxin and proteases?
    Entamoeba histolytica
  32. True/false: having a lot of diarrhea can sometimes lead to passing of trophozoites
    True; these trophozoites do not survive in the environment
  33. Which is the most common extracolonic site for Entamoeba trophozoites to invade?
  34. True/false: Entamoeba trophozoites penetrate areas with least motility
  35. True/false: there are commensal Entamoeba, but ELISA is able to distinguish between commensal ones and diarrheal ones
  36. Anchovy paste is seen in surgical drainage of _____
  37. Little man (aka heart or tear- shaped) shaped trophozoite is indicative of ______
    Giardia duodenalis
  38. True/false: Giardia trophozoite is binucleate and flagellated. While the cyst is 4-nucleate
  39. Which intestinal protozoa has a large ventral sucker used for attachment to intestinal villi?
    Giardia duodenalis
  40. Chronic infection of which organism can lead to malabsorption?
    • Giardia duodenalis, because of the large sucker that attaches to the intestinal villi causing malabsorption
    • Cryptosporidium can too
  41. Which organism can cause chronic, life-threatening illness in immunocompromised/ AIDS patients?
  42. Where do cryptosporidium replicate?
    they replicate inside the cells and killing the cells that way.
  43. True/false: cryptosporidiosis in non immunocompromised patient is self-limiting, while in immunocompromised patients it can cause fulminant cholera like watery diarrhea
  44. Which intestinal protozoan has acid-fast (pink/red) oocysts in fresh stool samples?
  45. Migratory parasite like Entamoeba can cause _____
  46. True/false: you cannot see trophs of cryptosporidium in stool because they are too tiny
    True. Whereas you may be able to see trophs of giardia because they are larger
Card Set
Intestinal Protozoan Microbiology
GI Final- Microbiology