1. GASTROINTESTINAL SYSTEM PROTOZOA -I-
Entamoeba histolytica
Giardia lamblia
Entamoeba coli
Doç.Dr.Hrisi BAHAR
Doç.Dr.Hrisi BAHAR

2. Gastrointestinal system protozoon
Entamoeba histolytica

3. INTESTINAL PROTOZOA Pathogenic Commensal Entamoeba histolytica
Balantidium coli
Giardia lamblia
Dientamoeba fragilis
Cryptosporidium parvum
Enterocytozoon bieneusi
Septata intestinalis
Cyclospora cayetanensis
Isospora belli
Commensal
Entamoeba hartmani
Entamoeba dispar
Entamoeba coli
Endolimax nana
Iodamoeba bütschlii
Chilomastix mesnili
Trichomonas hominis
Blastocystis hominis

4. Entamoeba histolytica (amoebiasis)
► Organism:Entamoeba histolytica
► At Risk : Anyone worldwide
► Humans Infected: 50 million cases of invasive disease/year
►Disease Outcome :100,000 deaths/year
► Available Drugs :Dose limiting side effects .

5. Entamoeba histolytica (amoebiasis)
Morphologic forms:
1- Active trophozoit form
*Cytoplasm:(2/3endoplasm and 1/3 ectoplasm)
* Nucleus: circle with karyosome
* Replication stage 2-4 nucleus

6. Entamoeba histolytica (amoebiasis)
Active trophozoit form

7. Trophozoit form

8. Entamoeba histolytica (amoebiasis)
2-Precystic form:
*Intermediate stage
*Low motility
*Untrue morphologic stage of parasites
*shape: oval or circle

9. Entamoeba histolytica (amoebiasis)
Precystic form
Precystic form

10. Entamoeba histolytica (amoebiasis)
3-Cystic form:
*Stable and non motile
*Small and large cysts
*Primary cyst with -1- nucleus
*In replication stage 2-4 nucleus
*Karyosome,, chromatoide body and glycogen in nucleus

11. Entamoeba histolytica (amoebiasis)
3-Cystic form:
Cystic form

12. Entamoeba histolytica (amoebiasis)
Replication stage of cyst

13. Entamoeba histolytica cystic forms

14. Entamoeba histolytica (amoebiasis)
Stability
*Trophozoit form: unstable
*Cystic form: stable in 20ºC for 3 days and In 45 ºC for 30 min
* Cystic form also stable against low concentration of CL and HCL

15. Entamoeba histolytica (amoebiasis)
Transmission
*It is transmitted by cystic form*
☻ Direct transmission
With contaminated hands
☻ Indirect transmision
With contaminated food , water
and arthropods.

16. Life cycle of Entamoeba histolytica

17. Entamoeba histolytica (amoebiasis)
Pathogenesis
► Cases acute dysentery
► Chronic stage: occur intestinal ulcer,inflammation and necrosis with proteolytic enzyme
► Heavy infection: occur intestine scleroses ,hypertrophy and perforation
► Metastases: to liver and brain…

18. Entamoeba histolytica (amoebiasis)
Intestinal ameobiasis
●Incubation period is 8 days or several month
● Acute stage: diarrhea with epithelium but
without blood, and abdominal pine , loss
of weight , flatulence and constipation.
● Sever infection : 10-20/day , diarrhea with
blood , abdominal pine (colon)dehydration and
fever.

19. Entamoeba histolytica (amoebiasis)
Extra intestinal amoebiais
► Spread of intestinal amoeba from blood to liver , spleen,brain and lung.
► Direct extra intestinal amoebiasis (without intestinal infection)

20. Entamoeba histolytica (amoebiasis)
Hepatit Amoebiasis
►Causes liver abscess
►Single abscess, different size , at the right lob of the liver.

21. Entamoeba histolytica (amoebiasis)
Hepatic Amoebiasis
►Symptoms: liver pine , fever right hypochondrium pain,rarely diarrhea
►Transmit to pleura, peritone and pericardial area…..dead.

22. Entamoeba histolytica (amoebiasis)
Hepatic Amoebiasis
AMOEBIC LIVER ABSCESS
Diagnosis
*Ultrasound
*Raised WBC
*Serology
*Aspirate microscopy
*Response to metronidazole 750 t.i.d.

23. Entamoeba histolytica AMOEBIC LIVER ABSCESS

24. Entamoeba histolytica (amoebiasis)
Pulmonary Amoebiasis
► 1- Direct primary infection (blood circulation)
► 2- secondary infection: after liver amoebiasis at the right pulmonary ..
Cases are with: single or several abscess

25. Entamoeba histolytica (amoebiasis)
Cerebral Amoebiasis
► Occur from complication of
liver and pulmonary amoebiasis..
► Cases are with single or several abscess

26. Entamoeba histolytica (amoebiasis
Spleen and Cutaneous Amoebiasis
► Spleen abscess always seem with liver amoebiasis.
► Cutaneous amoebiasis seem in perianal site.

27. Entamoeba histolytica (amoebiasis
Diagnosis
► Detection of trophozoit and
cystic form of parasites in fresh stool.
► After 30min trophozoit form will destroy.
► Extra intestinal amoebiasis:
detection of parasite cysts by lugol
stain of infected tissue.

28. Entamoeba histolytica (amoebiasis
trophozoit
trophozoit
Direct microscopy :
Detection of trophozoit and cystic form of parasites in fresh stool.

29. Entamoeba histolytica (amoebiasis
Treatment
► Metronidazole 750mg +
diloxanide furoate 500mg X 3 ..
10 days..
► Metronidazole + Iodoquinol 650mg X days
► Metronidazole +tetracycline 250mg X days

30. Entamoeba histolytica (amoebiasisOR
► Chloroquine 500mg X days (iiver amoebiasis) 0R
► Paromycine 250mg//kg X days

31. Gastrointestinal system protozoon
Entamoeba coli

32. Entamoeba coli
► Entamoeba coli is a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract especially in the colon.

33. Entamoeba coli
► Clinically, E. coli (not to be confused with the bacterium Escherichia coli) is important in medicine because it can be confused during microscopic examination of stained stool specimens with the pathogenic Entamoeba histolytica

34. Entamoeba coli
► The presence of E.coli does’nt need treatment treatment as it is considered harmless.
► However it should be noted that when a person becomes infected with this benign entamoeba, other pathogenic organisms may have been introduced as well, and these other pathogens might cause infection or illness.

35. Entamoeba coli
► The identification of intestinal amoebae depends on the size and shape of trophozoites and cysts and on number of nuclei and aspect of karyosome and chromatin.

36. Entamoeba coli
► Entamoeba coli trophozoites measure µm and have a vescicolous nucleus with a large eccentric karyosome and an irregulary distributed peripheral chromatin. The cytoplasm is vacuolated containing bacteria and yeast.

37. Trophozoite Entamoeba coli Serum physiologic 400X
► Entamoeba coli trophozoites
► Entamoeba coli trophozoites
Trophozoite Entamoeba coli Lugol 400X
Trophozoite Entamoeba coli Lugol 400X

38. Entamoeba coli
► E.coli cysts are spherical and measure µm (usually 15-20).
► Mature cysts have 8 nuclei with a large karyosome (central or eccentric) and an irregular (sometimes regular) chromatin.
► The nuclei can be numerated with careful focusing. ►

39. Entamoeba coli
► While this differentiation is typically done by visual examination of the parasitic cysts via light microscopy, new methods using molecular biology techniques have been developed also.

40. Entamoeba coli ►
E.coli cysts
E.coli cysts

41. Life cycle of E.coli
Life cycle of E.coli
Life cycle of E.coli

42. Entamoeba coli
► Cysts and trophosoits of E.coli are larger then E.histolytica.
► E.coli is the only species in the genus encountered in humans with more then four nuclei in the cyst stage.

43. Entamoeba coli
► Cysts and trophosoits of E.coli are larger then E.histolytica.
► E.coli is found in the mouth between the gingival pockets.

44. Gastrointestinal system protozoon Giardia lamblia (Giardia intestinalis)

45. Giardia lamblia ► It is an intestinal flagellate ► Lives in duodenum
and jejunum
► Cause “Giardiasis”

46. Giardia lamblia
► Human pathogen: G. lamblia or G. intestinalis or G. duodenalis,
► Two life stages: trophozoite and cyst.
HISTORY
► First observed 1681
by Anthony van
Leeuwenhoek

47. Giardia lamblia ► First observed 1681 by Anthony van Leeuwenhoek
► Described ~200 years later by Vilem Lambl
► First cultured in 1960’s
► Confirmed pathogen 1970’s
► One of most common intestinal parasites
► Causes Giardiasis (beaver fever)
►Geographic region with poor water sanitation

48. Giardia lamblia ► Species details ► G. intestinalis/lamblia
Single-celled protist
5 species of Giardia
► G. intestinalis/lamblia
G. muris in rodents, birds, reptiles
G. agilis in amphibians
G. ardae in great blue heron
G. psittaci in budgerigar

49. Giardia lamblia ► Morphology Cyst ► Infective stage in the
environment,
► Persist in cold water up to
several months
► Egg-shaped, 8-14µm by 7-10µm
► Organelle duplication w/out
cytokinesis results
*in four nuclei (Nu)
*four median bodies (MB)
*four axonemes (Ax)

50. Giardia lamblia ► Morphology Trophozoite
► Cannot survive in the environment
► Motile 4 pairs of flagella
► Pear shaped, bilaterally
symmetrical
► Relatively flattened, 10-12µm long
► 5-7µm wide with a large sucking disk on the anterior ventral side
► Two nuclei

51. Giardia lamblia - Life cycle -
2 trophozoites released per cyst
Multiply by binary fission every 12 h
Sucking disc used for attachment
Cyst forms in transit to colon

52. Clinical Symptoms and Pathogenesis
Giardia lamblia
Clinical Symptoms and Pathogenesis
► Ingested cysts excyst in response to stomach acidity.
► Attach (via their sucking disk) to microvilli of epithelium in small intestine, causing epithelial damage and interfering with gut transport processes.

53. Clinical Symptoms and Pathogenesis
Giardia lamblia
Clinical Symptoms and Pathogenesis
►Epithelial mucus is thinned, lymphocytes and other inflammatory cells infiltrate, physical blocking of absorption may occur, and enterobacteria may proliferate, causing more epithelial damage.
►Distention and flatulence can occur.

54. Clinical Symptoms and Pathogenesis
Giardia lamblia
Clinical Symptoms and Pathogenesis
► Symptoms include profuse and watery to semisolid, greasy, bulky and foul- smelling diarrhea; abdominal cramps; nausea; vomiting; anorexia; low-grade fever and flu-like headache. General malaise, weakness, weight loss.

55. Giardia lamblia
► Symptoms more likely in children and immunosuppressed adults than in healthy adults.
► Infectous dose is low (about 10 cysts; possibly less).
► Incubation period from 7-11 days.

56. Giardia lamblia ► Duration of illness varies: few days to months.
►Infection may resolve spontaneously. often, subchronic stage develops with mild to moderate symptoms occurring periodically.

57. Giardia lamblia
Epidemiology
► Many animals are major reservoirs: dogs, mice, horses, sheep….
► Contamination is by “Fecal-oral route”
► Transmission by contaminated water and food is common
► Transmission is generally in day-care centers, with poor hygiene and sanitation.

58. Giardia lamblia
Epidemiology
► Levels in sewage are estimated in the range of 3,000 to 30,000 per liter.
► Animal-to-human transmission occurs, but pathogenicity and virulence of non-human sources for humans is still uncertain.
► Strain differences documented both antigenically and genetically.

59. Giardia lamblia.“Diagnosis”
► Diagnosis is by microbiological examination of stool samples to check for the parasite.
► Because Giardia can be difficult to diagnose, the patient will ask to submit multiple stool specimens collected over a few days.

60. intestinalis trophozoite in a wet mount stained with iodine.
G.lamblia cysts stained by metilen blue
intestinalis trophozoite in a wet mount stained with iodine.
intestinalis trophozoite in a wet mount stained with iodine.
G.lamblia trophozoite in a wet mount stained with iodine. 60

61. Giardia lamblia :Diagnosis
► Microscopic detection based on finding distinctive trophs. or cysts in stools, with our without dye staining or immunofluorescent (fluorescent antibody) staining.
► Newer clinical diagnostic detection
by enzyme immunoassay (EIA; ELISA).
►Molecular detection by PCR is now
being used for detection and characterization.

62. Giardia lamblia Visualization methods
► Laser scanning cytometry
► Immunofluorescent antibodies
(Giardia –specific) for enumeration
► Differential interference contrast
(DIC) for confirmation4,6-diamidino 2
phenyl-indole dihydrochloride (DAPI)
for viability
► Propidium iodide (PI) for non-
viability

63. Electron microscopy pictures
Giardia lamblia
Electron microscopy
Electron microscopy pictures 63

64. Environmental Control of Giardia
► Water: physical and chemical treatment
(coagulation-flocculation, sedimentation, filtration and disinfection) will reduce Giardia
►Relatively resistant to chemical desinfection
but relatively sensitive to physical disinfection by UV radiation or heat.
► Pasteurization and thermal treatments is
effective for foods

65. Giardia lamblia ► Washing hands thoroughly with soap and water.
Protection from Giardiasis
► Washing hands thoroughly with soap and water.
► Not drinking untreated water or not use ice made from untreated water .
► Washing all food that is to be eaten raw by uncontaminated water..

66. Giardia lamblia Treatment
► Quinacrine HCl ,Metronidazole (Flagyl) and Furazolidone (Furoxone).
► Oral Quinicrine HCl cures about 90% of infections.
► Probiotics could help the
treatment

67. Giardia lamblia ► Fluid replacement is an
► Giardia can infect all people ,young
children and pregnant women .
► Rapid loss of fluids from
diarrhea can be especially
life threatening .
► Fluid replacement is an
important part of the treatment