1Originally described as an ameba
-no cystic stage
-related to the trichomonads (flagellate).
-Resembles Trichomonas
DIENTAMOEBA FRAGILIS
2DIENTAMOEBA FRAGILIS
-Co-infection with
Enterobius vermicularis
3DIENTAMOEBA FRAGILIS
-MORPHOLOGY
Rosette shaped nuclei (1 to 2)
-karyosome consists of four to six discrete granules.
4It was first discovered in 1681 by Antoine van Leeuwenhoek
in his own stools
GIARDIA LAMBLIA
5First described in 1859 by French scientist Dr. F. Lambl and
Czechoslovakian scientist Dr. Giard:
Cercomonas intestinalis
6In 1915 Stiles coined
Giardia lamblia
7 Giardia lamblia
-MORPHOLOGY
Trophozoite
✓ Pear/tear drop shaped, pyriform
✓ Bilaterally symmetrical
✓ “Old-man with eyeglasses”
✓ 4 pairs of flagella
✓ 2 nuclei with distinct karyosome (symmetrically bilateral)
✓ “Falling leaf motility” - movement
8✓ Ovoidal in shape
✓ Thick shell (double wall)
✓ Nuclei: 2 (young), 4 (mature)
✓ Presence of axonemes
CYSTS
9Cysts looks like
Coffee bean
10Causative agent of Giardiasis
(malabsorption syndrome) or
Lambliasis
11Giardiasis a.k.a.
“Traveler’s diarrhea”
12Giardiasis
-infections
Acute infections: “rotten eggs” odor = due to hydrogen sulfide
➢ Chronic infections:
✓ Steatorrhea → passage of greasy, frothy stools that may
float on toilet water
✓ Malabsorption of electrolyte, glucose, fluid
✓ Gay Bowel Syndrome
13Stool examination
➢ Direct fecal smear: cysts (1 hr-semiform) and trophozoites (30
min-watery) can be seen
14-may demonstrate Giardia trophozoites.
-The patient swallows a gelatin capsule attached to a
nylon string, with one end of the string attached to
the patient’s cheek.
Enterotest
15-If the parasite is not found in the feces,
this aspiration may be done
Duodenal aspirate
16Look at the intestinal villi if it is normal or
experiencing hypertrophy
Biopsy
17 it has the highest combination of
sensitivity and specificity.
Direct Fluorescent Antibody –gold standard
18Immunologic and Molecular Test
➢ EIA and ELISA
➢ Western Blot
➢ PCR
19Treatment for intestinal villi
Metronidazole,Nitazoxanide, Tinidazole (approved)
20The only pathogenic Trichomonas
➢ No cyst stage
➢ First observed by Donne in 1836 in purulent secretions of
male and female urogenital tracts.
TRICHOMONAS VAGINALIS
21TRICHOMONAS VAGINALIS Habitat
Urogenital tract
➢ Female: vulva (vagina)
➢ Male: prostate gland
22sexually transmitted disease called
trichomoniasis
23TRICHOMONAS VAGINALIS Morphology
“Rapid jerky tumbling”- movement
➢ Pyriform shape
➢ 4 anterior flagella
➢ Prominent axostyle
➢ Presence of undulating membrane
➢ Single nucleus
24Trichomoniasis Male symptoms
➢ Asymptomatic (less persistent, self-limiting)
25Trichomoniasis Female symptoms
➢ Greenish-yellow discharge
➢ Edema, itching, burning sensation
➢ vaginal pruritus
➢ “Strawberry cervix"
26Largest flagellate in man
CHILOMASTIX MESNILI
27CHILOMASTIX MESNILI Habitat:
Cecal region of the large intestine
28CHILOMASTIX MESNILI Morphology
✓ Asymmetrical
✓ Pear-shaped
✓ Spiral groove on midportion
✓ 3 anterior flagella
✓ 1 flagellum within the cytostome → Cystostomal fibril
(shepherds crook)
✓ “Boring/spiral movement or Cork-screw movement”
29Usually found in the intestines
➢ Commensal
➢ Relatively smaller than T. vaginalis
➢ Specimen: Stool (only this)
➢ occurs only as a trophozoite
➢ noninvasive
TRICHOMONAS HOMINIS
30TRICHOMONAS HOMINIS
-Mode of Transmission
fecal contamination of food and drinks
31Also known as Trichomonas buccalis
➢ Usually found in the mouth
➢ No cyst stage, only trophozoites
TRICHOMONAS TENAX
32Specimen for TRICHOMONAS TENAX
Mouth Scrapings
33 Mouth Scrapings
-Mode of transmission
contaminated dishes and utensils, kissing
➢ Trophozoites appear to durable: surviving several hours in
drinking water