Protozoa of this group possess one or more whip like flagella as their organs of locomotion Classification According to their habitat Lumen dwelling flagellates Alimentary canal – Intestinal flagellates Urogenital tract – Genital flagellattes 2.Hemoflagellates - flagellates found in blood and tissues Pathogenic: Intestinal flagellates - Giardia lamblia Duodenum, Jejunum -Diarrhoea. Genital flagellates - Trichomonas vaginalis Vagina, Urethra -Vaginitis , Urethritis Non pathogenic: Trichomonas tenax ( Mouth) Trichomonas hominis ( Caecum). Enteromonas hominis ( Colon) Dientamoeba fragilis( Colon)

1. FLAGELLATES

2. Protozoa of this group possess one or
more whip like flagella as their organs of
locomotion

3. Classification
According to their habitat
1. Lumen dwelling flagellates
• Alimentary canal – Intestinal flagellates
• Urogenital tract – Genital flagellattes
2. Hemoflagellates - flagellates found in
blood and tissues

4. Pathogenic:
Intestinal flagellates - Giardia lamblia
Duodenum, Jejunum -Diarrhoea.
Genital flagellates - Trichomonas vaginalis
Vagina, Urethra -Vaginitis , Urethritis
Non pathogenic:
• Trichomonas tenax ( Mouth)
• Trichomonas hominis ( Caecum).
• Enteromonas hominis ( Colon)
• Dientamoeba fragilis( Colon)

5. Giardiasis

6. Scanning electron micrograph (SEM) depicting a Giardia
lamblia protozoan undergoing binary fission, creating what
appears to be a microscopic "heart"

7. Life cycle

8. Leewenhoek discovered Giardia in his own stools

9. • World-wide in distribution
• caused by
- Giardia intestinalis / Giardia lamblia.

10. • Habitat:
- Duodenum & the upper part of
jejunum.
• Morphology: (exists in 2 forms)
- Trophozoite.
- Cyst.

11. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

12. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

13. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

14. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

15. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

16. TROPHOZOITE OF GIARDIA LAMBLIA
Shape: Viewed from front – Tennis racket shaped
Viewed from side – Longitudinally split pear

17. Trophozoite
• 14 u long x 7 u broad
• Bilaterally
symmetrical
• 2 nuclei
• 4 pairs of flagella
• 2 axostyles
• Motility: falling-leaf

18. • The dorsal surface is
convex & the ventral
surface is concave
with a sucking disc.
• Concave sucking disc
ventrally-used for
attachment to surface
of intestinal epithelial
cells.

19. Cyst
• Shape : oval
• Size: 12µm x 7µm
• Four nuclei displaced
to one pole
• axostyles lie
diagonally across
long axis forming a
dividing line within
cyst wall.
• Remnants of flagella
• Surrounded by tough
hyaline cyst wall.

20. Cyst
• Shape : oval
• Size: 12µm x 7µm
• Four nuclei displaced
to one pole
• axostyles lie
diagonally across
long axis forming a
dividing line within
cyst wall.
• Remnants of flagella
• Surrounded by tough
hyaline cyst wall.

21. Cyst
• Shape : oval
• Size: 12µm x 7µm
• Four nuclei displaced
to one pole
• axostyles lie
diagonally across
long axis forming a
dividing line within
cyst wall.
• Remnants of flagella
• Surrounded by tough
hyaline cyst wall.

22. Cyst
• Shape : oval
• Size: 12µm x 7µm
• Four nuclei displaced
to one pole
• axostyles lie
diagonally across
long axis forming a
dividing line within
cyst wall.
• Remnants of flagella
• Surrounded by tough
hyaline cyst wall.

23. LIFE CYCLE
• in one host
• Mature cyst is the infective form
• Mode of infection – Faeco-oral route
• Within 30 min excystation occurs in the duodenum
• One cyst forms two trophozoites, which multiply by
binary fission and colonises the duodenum and upper
part of jejunum
• To avoid acidity of duodenum they may localises in
biliary tract
• By means of concavity of ventral surface it attaches to
mucosal surfaces of duodenum and jejunum.
• Encystation occurs while transit down the colon

24. Trophozoite in
the intestine
of man
Multiply by
binary fission
During
unfavourable
conditions,
encystment
occurs in
large intestine
Infection in
man occurs
by ingestion of
cyst
Each cyst
hatchesout
two
trophozoites
Trophozoites
multiply and
localises in
duodenum
Due to high
acidity of
duodenum,
trophozoites
localises in
billiary tract

25. Cyst
• Shape : oval
• Size: 12µm x 7µm
• Four nuclei displaced
to one pole
• axostyles lie
diagonally across
long axis forming a
dividing line within
cyst wall.
• Remnants of flagella
• Surrounded by tough
hyaline cyst wall.

27. Pathogenesis
• Does not penetrate mucosa or invade tissue.
• remains tightly attached to surface epithelial
cells of duodenum and jejunum by sucking
disc.
• structure and function of villi of intestines is
disturbed causing disturbance of intestinal
function, leading to
1. malabsorption of lipids and lipid soluble
vitamins
2. diarrhoea

28. Clinical disease
• watery diarrhoea
• Foul smelling stools, no pus or blood
• Flatulence
• Abdominal distention
• Mal absorption

29. PATHOGENESIS AND
SYMPTOMS
• It is present within the glandular crypts
of duodenal and jejunal mucosa.
• It does not invade the tissues
• Duodenitis and jejunitis

30. GIARDIASIS PRESENTATION
• Incubation: one to two weeks
• Giardia may cause symptoms by creating a
brush border enzyme deficiency.
• Onset: gradual
• Symptoms: nausea, vomiting, malaise,
flatulence, bloating, cramping, mild
diarrhea, steatorrhea
• The stool is voluminous,foul smelling,large
amount of mucus anfd fat but no blood.
• Sequelae: malabsorbtion, lactase
deficiency, weight loss, fatigue, depression
and rarely reactive arthritis or urticaria

31. 2. Pathogenesis and symptoms
G. lamblia inhabits in the duodenum and upper
jejunum
Trophozoites are attached to the mucosa
surface by sucker, reproduced by binary fission
Histology: shortening of microvilli, elongation of crypts,
and damaging the brush border of the absorptive cells
Diarrhea, abdominal pain, bloating,
nausea, and vomiting
Mechanical blockage of the intestinal mucosa,
competition for nutrients, inflammation

32. LABORARORY DIAGNOSIS
• Identification of cyst in formed stools
and trophozoites in diarrhoeal stool.
• As the parasites are attached firmly to
the mucosa by means of sucking disc,
even 5 or 6 samples may not show
any parasite.
• Trophozoites may also be detected in
duodenal aspirates.
• Useful method for obtaining duodenal
aspirate is ENTEROTEST

33. Prevention and Control
• Public Health:
– Sewage treatment
– Treated drinking water
– Medicating infected members of the public
– Monitoring and treatment of food handlers
• Personal:
– Boiling stream water for minimum of 1 minute
– Iodine tablets
– Avoid contaminated water
– Keeping hands clean and dry
– Thoroughly drying utensils and dishes
– Treat any pets showing signs of infection

34. Lab Diagnosis
Microscopic examination of
freshly passed stools.

35. Trichomoniasis

36. TRICHOMONADS
• 3-5 anterior flagella
• one undulating membrane
• axostyle
• hydrogensome (EM)
Human Trichomonas Species
T. tenax oral cavity
T. hominis* intestine
T. vaginalis uro-genital
*aka: Pentatrichomonas

37. TRICHOMONAS VAGINALIS
Normal inhabitant of vagina, prostate and urinary
tract
Obligate parasite
Morphology – pear shaped trophozoite,10-30um
in length and 5-20um broad
4 ant flagella and cystostome, ant end is rounded
Post end pointed
Undulating membrane up to middle, an axostyle
is also present
Motile by jerky movement, divide by binary fission
No cyst form

38. Caused by Trichomonas vaginalis
Habitat
In females – urethra and vagina
In males – urethra and prostate gland

39. Morphology
Occurs only as trophozoite form.
No cystic form.

40. • Ovoid or pear shaped
• 13 x7 u
• Short undulating
membrane reaching upto
the middle of body
• Single nucleus
• Prominent axostyle
projects posteriorly
• 4 anterior flagella and fifth
runs along outer margin
of undulating membrane
• Motility – rapid, jerky

41. • Sexually transmitted
disease
• In women – leukorrhea,
vaginitis.
• In men, usually
asymptomatic. May
develop urethritis,
prostatitis, cystitis.

42. Lab diagnosis
Microscopy of :
• Vaginal or urethral discharge
• Urine sediment
Direct wet mount – actively motile
trophozoites seen.

43. DIAGNOSIS
• demonstration of parasite
• direct observation or in vitro
culture
• vaginal discharge
• urine sediment
• prostatic secretion
TREATMENT
• metronidazole (Flagyl)
• 250 mg (3/d) for 5-7 days
• single 2 g dose
• simultaneous treatment of partner!
(85-90% cure rate)
PREVENTION
• limit # of sexual
partners
• condoms

44. Key Features of Cysts
• oval shape
• 11-14 x 6-10 m
• distinct cell wall set apart from
cytoplasm
• 4 nuclei at anterior end
• large karyosome, no peripheral
chromatin
• fibrils (axonemes) evident
• median bodies

47. • pear shape
• 12-15 x 5-10 x 2-4 m
• 2 nuclei
• large karyosome, no peripheral
chromatin
• fibrils (axonemes) evident
• bilateral symmetry
• pair of median bodies
• adhesive disk (not always evident)
• 4 pair flagella
• motility likened to falling leaf
Key Features of Trophozoites

49. Other Flagellates Found
in Human Feces
• Dientamoeba fragilis
• no flagella (discuss with amebas)
• Pentatrichomonas hominis
• formerly called Trichomonas hominis
• Chilomastix mesnili
• Enteromonas hominis
• Retortamonas intestinalis

50. Non-Pathogenic Intestinal
Flagellates
• 7-15 mm trophozoite
• no cyst
• single nucleus
• axostyle
• 4 free flagella + undulating
membrane
• costa
Trichomonas hominis

51. Non-Pathogenic
Intestinal Flagellates
Chilomastix mesnili
• 10-20 mm trophozoite
• 6-20 mm cyst
• single nucleus
• 4 flagella
• cytostome

52. Chilomastix mesnili
T. hominis

53. THANK YOU