1. Intestinal` Protozoa

2. Giardia lamblia Giardia trophozoites (light microscope)
( SEM)

3. Giardia trophozoites
(light microscope)

4. Giardia cyst
(light microscope)

5. Giardia trophozoites
(light microscope)
Trichrome stain
Unstained

6. Giardia lamblia :
Life cycle

7. Giardia cyst (light microscope)
Trichrome stain
Unstained

8. Giardia trophozoites in tissue section

9. Giardia cyst and trophozoites IH stain

10. Giadriasis: Clinical Picture
Asymptomatic infections ( majority)
Symptomatic Infections:
Typical picture: IP 1-2 wks followed by diarrhoea for about 6 wks,
Atypical : Severe diarrhoea , malabsorption especially in children

11. Giardiasis: Laboratory diagnosis
Stools examination :cysts or trophozoits
Examination of duodenal contents : trophozoites

12. Giardiasis: Chemotherapy
Drug of choice: Metronidazole

13. Intestinal Amoebae

14. Entamoeba coli

15. Iodamoeba butschlii trophozoite

16. Iodamoeba butschlii cyst

17. Endolimax nana cyst
Endolimax nana cyst

18. Endolimax nana trophozoite
Endolimax nana cyst

19. E. polecki cyst
E. polecki trophozoite

20. Entamoeba coli (drawing)
Entamoeba coli (Eosin)

21. Entamoeba coli ( cyst )

22. Entamoeba coli ( trophozoite)

23. Entamoeba hartmanni

24. Entamoeba hartmanni

25. Entamoeba histolytica

28. Entamoeba histolytica

29. E. histolytica
E. histolytica

30. Entamoeba histolytica

31. Entamoeba histolytica

32. ENTAMOEBA HISTOLYTICA…
500 million people are infected. 100,000 deaths per year. Worldwide distribution. It is a waterborne infection.
There are 6 species of Entamoeba:
histolytica dispar
hartmanni coli
gingivalis polecki

33. E. histolytica vs E. dispar
Entamoeba histolytica : amoebae that are pathogenic.
E. dispar The non invasive form .
The 2 amoebae can’t be distinguish by microscopic
observation.

34. Entamoeba histolytica
Mode of infection
Water, food
Flies can act as vector..
Can be sexually transmitted person -to -person contacts
Not a zoonosis

35. Entamoeba histolytica
Life cycle
Trophozoite: vegetative stage, must encyst to survive in the environment. It is a fragile structure. Pre cyst: encysting trophozoites disgorging any undigested food.
Cyst: infective stage. Resist to the harsh conditions of the environment.

36. Entamoeba histolytica
The infective dose can be as little as 1 cyst. be as little as 1 cyst.
The incubation period can be from few days to can be from few days to few weeks depending on the infective dose
Cysts can survive for weeks at appropriate weeks at appropriate temperature and humidity.

37. Entamoeba histolytica
PATHOLOGY
Intsetinal amoebiasis :
Remarkable and unique ability a to hydrolyse host host
tissues with their active cysteine proteases present on the surface membrane of the trophozoite.
Lesions are found in the caecum, appendix, or colon.
They may heal. If perforation of the colon occurs, They may heal. If perforation of the colon occurs,
My lead to a peritonitis that can lead to death. Amoeboma
Granuloma obstructing the bowel

38. PATHOLOGY:Intsetinal amoebiasis :

39. PATHOLOGY:Intsetinal amoebiasis :

40. PATHOLOGY : Intsetinal amoebiasis
Complications

41. Intsetinal amoebiasis :
PATHOLOGY
Intsetinal amoebiasis :
Entamoeba histolytica

42. Intsetinal amoebiasis :
PATHOLOGY
Intsetinal amoebiasis :
Entamoeba histolytica

43. Intsetinal amoebiasis :
PATHOLOGY
Intsetinal amoebiasis :
E. Histolytica in mucosa. in mucosa.
Numerous Numerous
trophozoites can be
seen with ingested seen with ingested erythrocytes.

44. PATHOLOGY: Extra-intsetinal amoebiasis :

47. Free-living Amoebae

48. Acanthamoeba in corneal scraping

49. Acanthamoeba trophozoite

50. Acanthamoeba brain

51. Acanthamoeba

52. Acanthamoeba ulcer

53. Naegleria brain

59. Cryptosporidium oocysts

60. Cryptosporidium , safranin
Cryptosporidium , acid-fast stain

61. Cryptosporidium , acid-fast stain

63. Cryptosporidium