Classification of flagellates and giardia lamblia

Microbiology

1. CLASSIFICATION OF
FLAGELLATES
and
GIARDIA LAMBLIA

2. FLAGELLATES
Parasitic protozoa with whip like flagella
Phylum-Sarcomastigophora
Subphylum-Mastigophora
Class-zoomastigophora

3. Classification
(Depending on habitat)
Hemoflagellates-in blood and tissues
-Posess kinetoplast ,1flagellum.
Lumen –dwelling flagellates:in alimentary tract and and
urogenital tract
-No kinetoplast
-multiple flagella

4. Most lumen dwelling flagellates are non
pathogenic commensals except:
-Giardia lamblia
-Trichomonas vaginalis

5. GROUP PARASITES HABITAT
Lumen –dwelling
flagellates
Giardia Lamblia
Trichomonas vaginalis
Trichomonas tenax
Trichomonas hominis
Chilomastix mesnili
Enteromonas hominis
Retortamonas
intestinalis
Dientamoeba fragilis
Duodenum and jejunum
Vagina and urethra
Mouth
Large intestine(caecum)
Large intestine(caecum)
Large intestine(colon)
Large intestine(colon)
Large intestine(caecum
and colon)
Hemoflagellates Leishmania supp.
Trypanosoma brucei
Trypanosomacruzi
Reticuloendothelialcell
Connective tissue and
blood
Reticuloendothelial cell
and blood.
FLAGELLATES

6. GIARDIA LAMBLIA

7. History
•First observed by Dutch scientist Antonie
von Leeuwenhoek in his own stool
•.
•Naming-
Giardia-Professor Giard
Lamblia-Professor Lamble

8. Distribution
Most common-worldwide in distribution.
Endemicity very high in areas with low
sanitation mainly tropics.
Visitors to such places develop the disease-
travellersdiarrhea.

9. Habitat
Lives in duodenum and upper
jejunum(within crypts)

10. Morphology
Exists in 2 forms:
•Trophozoite [vegetative form]
•Cyst [cystic form]

11. Trophozoite

12. •Shape of tennis racket (heart/pyriform shape)
•Measures 15x4x3xµm
•Dorsally convex
•Ventrally concave with a sucking disc.
•Bilaterally symmetrical and has:
1 pair of nuclei
4 pairs of flagella(motile)
Blepharoplast
1 pair of axostyle
2 sausage shaped parabasal/median body.

14. CYST

15. Cyst
-Small and oval ,12µm x10µm
-Surrounded by hyaline cyst wall.
-2 pairs of nuclei (young 1)
-axostyle is diagonal.
-Remnants of flagella and sucking disc may be seen

16. Axostyle

17. Modes of transmission
•Cyst is the infective form.
•Contaminated food and water.
•Person to person transmission-
In children
Homosexuals and
Mentally ill persons
.

18. Predisposing factors
•Achlorhydria
•Use of cannabis
•Blood group A
•Chronic pancreatitis
•Malnutrition
•Immune defects-19A deficiency,
hypogammaglobulinemia

19. Life Cycle
1 host
Infective form-Mature cyst
Cyst ingested by man
2Trophozoites
colony
(Binary fission)
(Excystation)

20. Excystation occurs
in stomach
Trophozoites remain
within crypts in
duodenum,jejunum
Cyst formation takes
place as trophozoites
move down to colon
Trophozoites,cysts in
feces;cysts survive
long
Ingestion of cysts in
contaminated food
and water.

21. Cysts remain viable for several weeks.
•There may be 200,000 cysts passed per gram of
feces.
•Infective dose-10-100 cysts.
•Incubation period -2 weeks

23. Pathogenicity
-Tightly adheres to intestinal epithelium.
oCauses abnormalities of villous architecture by:
-apoptosis
-increased lymphatic infiltration of lamina propria
-suction force
oVariant specific surface proteins(VSSP)
-Virulence and infectivity.
-Protection from proteases in intestine.

24. Giardia about to settle on
intestinal wall.

25. Giardia adhered to intestinal wall

26. Giardia lamblia clinging to the
wall of duodenal villus.

27. Clinical features
-
Fat
malabsorption.
Diarrhoea
Epigastric pain
Flatulence

28. Laboratory Diagnosis
Stool examination:
-Macroscopic examination
-Microscopic examination
Enterotest (string test)
Serological test:
-Antigen detection: ELISA,IIF
-Antibody detection: ELISA,IIF
Molecular diagnosis:DNA probe,PCR

29. Stool Examination
Macroscopic examination:
-Offensive odour,pale coloured ,fatty &
floats

30. Microscopic examination:
Cysts under microscope:

31. Trophozoites under microscope:

32. Enterotest
Method to obtain duodenal specimen
A coiled thread inside a gelatin capsule swallowed
by patient.
After 2 hours it is withdrawn,placed in saline and is
mechanically shaken.
The centrifuged deposit of the saline is examined.
Enterotest
Capsule

33. Capsule withdrawn
and mechanically
shaken

34. Serodiagnosis
Antigen detection:
-ELISA,IIF and Immunochromatographic Tests.
-Presence of antigen indicate active infection
-Giardia specific antigen 65(GAS 65)
-Sensitivity -95%
-Specificity 100%

35. ELISA
Giardia strip test

36. Antibody Detection
-IIF and ELISA used
.
-Lack sensitivity and specificity.

37. Molecular Method
•DNA probes
•PCR

38. Treatment
•Metronidazole
•Tinidazole
•Furuzolidone
•Nitazoxamide
•Parmomycin-pregnancy
-Children

39. Prophylaxis
Giardiasis can be prevented by:
Proper disposal of waste water and feces.
Practice of personal hygiene
Handwashing before eating and proper disposal
of diapers.
Prevention of food and water contamination
-Boiling and filtration

40. Prophylaxis

41. THANK
YOU!