AMOEBAE - GIARDIA- TRICHOMONIASIS - SECOND MBBS STUDENTS - UNDERGRADUATE STUDENTS - MEDICAL COLLEGE - POWERPOINT

1. FREE LIVING AMEBAE,
GIARDIA LAMBLIA & TRICHOMONAS
VAGINALIS
Dr. R. Someshwaran, MD.,Assistant professor,
Dept. of Microbiology,
Karpagam Faculty of Medical Sciences & Research,
Othakalmandapam, Coimbatore-641032

2. OBJECTIVES
• To define etiology, morphology, life cycle,
disease caused, laboratory diagnosis and
treatment of pathogenic free living amebae
infections.
• To elaborate on morphology, life cycle, disease
caused, laboratory diagnosis and treatment of
Giardia lamblia infections and Trichomonas
vaginalis infections.

3. GIARDIA LAMBLIA

4. GIARDIA LAMBLIA

5. GIARDIA LAMBLIA
• World wide
• Habitat:
Duodenum and upper part of Jejunum
• Morphology: 2 phases
1. Trophozoite;
2. Cyst
Giardia intestinalis / Lamblia intestinalis

6. GIARDIA LAMBLIA

7. GIARDIA LAMBLIA
• Trophozoite:
• Tennis or badminton racket shaped
• Dorsal surface convex; ventral surface concave
with a sucking disc
• Size: 14µm long by 7µm broad
• Anterior end broad and rounded and posterior
end tapers to a sharp point
• Bilaterally symmetrical with all organs paired
• 2 axostyles, 2 nuclei, 4 pairs of flagella

8. GIARDIA LAMBLIA
• Cyst
• Oval in shape
• 12µm long by 7µm broad
• Diagnonally lying axostyle
• 4 nuclei – clustered at one end or lying as
pairs in the centre
• Encystment of parasite occurs in acidic
environment

9. GIARDIA LAMBLIA
• Culture:
• CO-CULTIVATION OF Giardia with Candida
guillermondi in presence of chick embryo
extract, human serum, Hottinger’s digest
(tryptic meat digest) & hank’s solution

10. Immunology
• Common in younger age group
• Uncommon in adult (Efficient immunity) CMI
& HI
• IgA deficiency – risk factor (Anti-IgA Ab
demonstrated on surface of Giardia
trophozoites obtained from jejunal biopsies or
fluid)
• Raised anti-Giardia IgG (Chronic infection)

11. GIARDIA LAMBLIA – Life cycle

12. Pathogenisis & Clinical spectrum
• Sucking disc – Attaches to intestinal
epithelium
• Malabsorption of fat, Persistent loosening of
bowel, passage of yellowish or greyish and
greasy stool with excess of fat (Steatorrhoea)
• Silent case, Chronic enteritis, Acute
enterocolitis with malabsorption syndrome
• Fever, anemia and allergic manifestation,
Chronic Cholecystopathy

13. Laboratory diagnosis
• STOOL MICROSCOPIC EXAMINATION:
Trophozoites (Falling leaf motility), Cysts
• Fluorescent method using monoclonal
antibodies
• ELISA done but Anti-Giardia antibodies - Serum
– not useful
• Enterotest – trophozoites (Duodenum, Jejunum)
• DNA probes

14. GIARDIA LAMBLIA
• TROPHOZOITE

15. GIARDIA LAMBLIA
• ENTERO TEST or GELATIN CAPSULE TEST

16. GIARDIA LAMBLIA

17. GIARDIA LAMBLIA
• Treatment:
• Metronidazole 250 mg TDS for 5 days
• Trimidazole 2 gms once
• Furazolidone 100 mg QID, for 7-10 days

18. TRICHOMONAS VAGINALIS

19. TRICHOMONAS VAGINALIS
• Common flagellates of tropics
• Frequently onservedin diarrhoeal stool
• Exists only in trophozoite form with single
ovoid nucleus, cystosome, undulationg
membrane, Costa, 3-5 anterior flagella
• No cyst form

20. TRICHOMONAS VAGINALIS

21. TRICHOMONAS VAGINALIS

22. TRICHOMONAS VAGINALIS
• Pentatrichomonas hominis – 8µm (Ileo-cecum)
• Trichomonas tenax (Oral cavity)
• Trichomonas vaginalis (Female genital tract)

23. LIFE CYCLE

24. TRICHOMONAS VAGINALIS
• T. vaginalis – worldwide – Leucorrheic
discharge in females (White discharge)
• But found in both males and female urinary
tract
• Sexually transmitted disease (Homosexuals,
Periano – Orosexuals) causing urethritis.
• Motile trophozoites with jerky movement in
vaginal or urethral smear microscopy or in
prostatic secretions

25. TRICHOMONAS VAGINALIS

26. TRICHOMONAS VAGINALIS

27. TRICHOMONAS VAGINALIS

28. PATHOGENIC FREE LIVING
AMEBAE
Naegleria fowleri
Acanthamoeba
Balamuthia mandrillaris

29. LIFE CYCLE

30. Naegleria fowleri

31. NAEGLERIA FOWLERI
Worldwide distribution
Motile at 21⁰C –Brisk by Lobopodia
(Pseudopodium)
• 3 forms
1. Trophozoite or ameboid form
2. Free swimming flagellate (Pear shaped wit 2
flagella)
3. Cyst or resting form (uninucleate)
Limex form (Slug shaped – One broad end and
other pointed)

32. Trophozoite and Flagellate forms –
infective forms

33. NAEGLERIA FOWLERI

34. NAEGLERIA FOWLERI

35. Lab diagnosis
• CSF Wet mount examination
• Wright or Giemsa stain
• Flurescent antibody staining of CSF
• Proteose peptone glucose medium to culture

36. NAEGLERIA FOWLERI
• Primary amoebic meningo-encephalitis

37. NAEGLERIA FOWLERI

38. NAEGLERIA FOWLERI

39. NAEGLERIA FOWLERI

40. PAM
• Fowler & Carter 1965
• US, India, Australia, Czechoslovakia, Britain, New
Zealand.
• Naegleria – mud, water, moist soil, lake stream,
ponds, indoor swimming pool
• Mesopharyngeal contamination or by close
contact or by inhalation of droplets
• Neurotropic, cerebral invasion via olfactory
nerves.
• Acute URTI – with Signs of meningitis

41. PAM
• Rapid and fatal course if not treated
• Treatment: Amphotericin B 1mg/kg/day IV for
several days or Ketoconazole 800 P.O for 1
month

42. Acanthamoeba culbertsoni

43. Acanthamoeba spp.,
• A. castellani
• A. culbertsoni
• A. polyphaga
• A. rhysode

44. Acanthamoeba
• World-wide
• method of transmission – not known
• Not due to contact with warm fresh water
• 2 forms
• Trophozoite, Cyst – both are infectious

45. ACANTHAMOEBA

46. ACANTHAMOEBA
• Acanthamoeba keratitis – common in contact
lens users

47. ACANTHAMOEBA
CSF / Corneal scraping

48. Acanthamoeba
• Culture with Escherichia coli useful
• Indirect fluorescent antibody tests (IFAT)
• Treatment: No effective treatment for GAE, but
for Keratitis – enucleation of ulcer and
corneal transplant is the choice

49. Balamuthia mandrillaris

50. Balamuthia spp.,
• Produce Granulomatous Amoebic Encephalitis
- GAE (CNS) like Acanthamoeba
• Worldwide
• 2 forms Trophozoite and Cyst
• Life cycle is also same
• Microscopy and Tissue culture of CSF
• Treatment: Not known

51. BALAMUTHIA MANDRILLARIS

52. BALAMUTHIA MANDRILLARIS

53. SUMMARY & TAKE HOME MESSAGE

55. THANK YOU