1. Intestinal Flagellates
(Gardia intestinalis)
Prepared by:
NOE P. MENDEZ
CENTRAL MINDANAO UNIVERSITY (CMU)
npolomendez@gmail.com

2. INTESTINAL FLAGELLATES
Chilomastix mesnili (non-pathogenic)
Enteromonas hominis (non-pathogenic)
Retortamonas intestinalis (non-pathogenic)
Trichomonas hominis (non-pathogenic)
Dientamoeba fragilis (non-pathogenic)
Giardia intestinalis (pathogenic)

3. Stages of
Intestinal
Flagellates

4. Giardia intestinalis
 Also known as G. duodenalis.
 Diseases: Giardiasis, lambliasis, flagellate diarrhea.
 Geographic distribution: world wide, more prevalence in warm
climates.
 Consist of 2 stages: 1)trophozoite 2)cyst
 Trophozoite: 9-20µm in length, 5-15µm in width, oval to pear
shaped, 2 nucleus,
 Cyst: 8-18µm in length, 7-10µm in width, oval, more eccentric
karyosome, 4 median bodies (mature cyst), 4 nucleus (mature
cyst).

5. G. intestinalis (trophozoite)
 K= karyosome
 Nu=nucleus
 MB=median body
 Fg=flagella
 Ax=axoneme
 AD=adhesive disk

6. Gardia intestinalis under
EM
Trophozoite Stage

7. G. Lamblia (cyst)
Nu=nuclues
K=karyosome
Ax=axoneme
MB=median
body
CW=cyst wall

8. Gardia intestinalis
under EM
Cysts Stage

9. Life Cycle

10. Infective stage: cyst
Acquired by ingestion passage through stomach
small intestine  duodenum  large intestine 
pass in stool  environment.
Duodenum= excystation occurs  trophozoite
multiply itself by longitudinal binary fission
(approximately 8 hours intervals).
Large intestine= encystation occurs.
Both trophozoite and cyst can be found in the feces.

11. Transmission & Pathogenesis
 The most pathogenic intestinal flagellate.
 Distribution: world wide
 Found in the gastrointestinal tracts of a variety of
mammals, including man.
 Habitat: ponds, lakes, stream.
 Resistant to chlorine.
 Filtration is necessary to eliminate contamination.

12. Transmitted via: water, foods (fruits and raw
vegetables), person to person contact (oral-anal
sexual practices).
Incubation period bout 2-3 weeks  get
symptoms: watery foul-smelling diarrhea,
abdominal cramps, flatulence, anorexia, and
nausea.
Also have fat-soluble deficiencies, folic acid
deficiencies, hypoproteinemia with
hypogammaglobulinemia and structural changes in
intestinal villi.

13. Severe cases: get malabsorption syndrome
and steatorrhea, and weight loss.
Patient r often, however asymptomatic.
How d parasite attaches to the intestinal
mucosa? By the sucking disc/adhesive disc
located on the ventral side of the cell.

14. Treatment
Metronidazole
Quinacrine
Tinidazole
Furazolidone
Paromomycin

15. Prevention
 By avoidance of contaminated water.
 Filtration (this parasite resistant to chemicals such as chlorine).
 Protecting water supplies from reservoir hosts such as beavers, muskrats
and voles.
 Exercising good personal hygiene.
 Safe sexual practices.

16. Thank you 