Flagellates I
Genito-urinary & Intestinal
flagellates
Dr. Anuluck Junkum
PARA 317221
Objective
 Can describe the morphology, life cycle,
pathology, diagnosis and prevention
of pathogenic flagellate
Classification of Protozoa
Based on locomotive organs :
 Amoeba :
 Ciliate :
Pseudopodia
Cilia
 Sporozoa :
Body flexion or Gliding
 Flagellate :
Flagella
flagella
Flagellates
*
Medical important flagellates
1. In GI tract :
Non-pathogen
Giardia lamblia
Dientamoeba fragilis
Trichomonas hominis
Trichomonas tenax
Chilomastix mesnili
2. In GU tract :
Trichomonas vaginalis
3. In blood & tissue :
Leishmania spp. &
Trypanosoma spp.
Giardia lamblia
Name : Giardia lamblia, Giardia intestinalis
Disease:
Giardiasis
Distribution:
- Cosmopolitan (most commonly in warm climate)
- most common flagellate of human digestive tract
Morphology
Trophozoite
Sucking disc
nucleus
median bodies
axoneme
flagellum
Size : 5-15 x 9-21 um
• Pear-shaped (tear drop)
• dorsal surface : convex
• ventral surface : concave
• 2 ventral sucking disc
• 2 nucleic central karyosome
• In middle :
axoneme & median bodies
• 4 pairs of flagella
Giardia lamblia (Trophozoite)
Sucking disc
Microvilli
Cross section of small intestine
Morphology
Mature cyst
• oval shape with 4 nuclei
• no flagella and sucking disc
4 nuclei
• presence : median bodies,
axoneme
median bodies
axoneme
Size : 8-14 x 7-10 um
• smooth, colorless cyst wall
• after excystation:
transforms into 2
binucleated trophozoites
Axoneme
Giardia lamblia (cyst)
Fragments of
sucking disc
Axoneme
Nucleus
Cyst wall
• 2-15% infection rates in various parts of the world
• Group infection (children > adult)
• Fecal-oral transmission (with mature cyst)
- contaminated food & water
Hiker’s diarrhea or Picnicker’s disease
- direct contaction
- sexual transmission (also Homosexual)
• RH : cats and dogs
- Most cases : asymptomatic
- Symptomatic cases
* hypercellularity of the lamina propria (mucosa)
irritation of epithelial cell
increase mucus production
* malabsorbtion, steatorrhea without blood
* typical symptoms:
- steatorrhea without blood
- abdominal cramp, diarrhea,
- dehydration, weight loss
* obstruction of gall bladder
jaundice
• Stool examinations
- “falling leaf” motility of trophozoites
(difficult to see in mucus stool)
- non-motile cyst
• Duodenal drainage or in combination with
EnteroTest® capsule
• Immunodiagnosis: ELISA, IFA
EnteroTest® capsule
•
Metronidazole
(200-400 mg., 3 times a day)
•
Ornidazole
( 2 g. single dose)
• Education of :
- personal hygiene
- improved sanitary : water treatment (boil or filtrate)
• control of insects
• properly treatment of
symptomatic and asymptomatic patients
Dientamoeba fragilis
Dientamoeba fragilis
• Habitat :
large intestine (cecum)
• Distribution :
cosmopolitan
• Locomotive organ : pseudopodia
• grouped to Flagellate : based on ultrastructure
immunological & genetic
evidence
Morphology
Size 5-12 um
- Trophozoite stage only
- amoeba-like
- Nucleus :
• no peripheral chromatin
• 2 nucleus, big karyosome
- food vacuole in cytoplasm
Life cycle
o Transmission between human : unclear
o not invade tissue
o Irritate intestinal mucosa
- increase mucus & intestinal movement
- abdominal pain, diarrhea (mucous)
- nausea, vomiting, low fever
- anal pruritus
• Stool examination
- fresh smear (mucus area)
may be confused with E. histolytica
- permanent smear
• iodoquinol
650mg., 3 times a day, 20 D.
• tetracycline
500mg., 4 times a day, 10 D.
• paramomycin
500mg., 3 times a day, 7 D.
Trichomonad
Trichomonad
undulating
membrane
nucleus
flagellum
karyosome
axostyle
• pyriform shape
• longitudinal binary fission
T. tenax
(mouth)
T. hominis
(large intestine)
T. vaginalis
(urogenetal tract)
Morphology
T. tenax
T. vaginalis T. hominis
Length (µm)
5-12
7-23
No. ant. Flag.
4
4
Undulating mem. 3/4 of body 1/2 of body
Post. free flag.
-
5-14
5
posterior
1
Trichomonas tenax
Size : 5x12 µm
• non-pathogenic flagellate
• habitat : mouth
(tartar from teeth)
• Transmission : unclear
may be cough, sneeze,
kissing, co-use utensil
• undulating membrane :
3/4
of body length
• feed on bacteria, epithelial cell
Trichomonas hominis
Size : 5-15x7-10 µm
• non-pathogenic flagellate
• habitat :
large intestine
• most common found next to
G. lamblia & D. fragilis
•
Transmission
: unclear
• undulating membrane :
cover entire body &
projects like a free flagellum
• movement : jerky,
non-direction
Trichomonas vaginalis***
• Disease:
• Habitat :
Trichomoniasis
Female: vagina, urethra
Male: urethra, prostate gland
• Distribution :
•Transmission:
cosmopolitan
sexual transmission
Morphology
- Only trophozoite stage*
- tear drop-shaped
- 4 anterior flagella
- 1 nucleus at anterior part
- undulating membrane = ½ of body length
- jerky movement
size 7-15x4-7 um
Epidemiology
• high prevalence : 16-35 years old (Female)
• feed on : bacteria & wbc (phagocytosis)
Symptoms
• Asymptomatic:
• Symptomatic
Female
20-50% (male usually asymptomatic)
*:
- vaginal discharge (foul smell, creamy)
- leukorrhea, dysuria
- vaginitis, cystitis, vaginal & vulva pruritis
Male
- mild symptom
- itching, cystitis, prostatitis
T. vaginalis parasite adhering to vaginal epithelial cells
Vaginitis due to T. vaginalis
foamy vaginal discharge
Strawberry cervix of trichomoniasis
Diagnosis
 Microscopic examination
*
- wet preparation & vaginal swab
(vaginal, urethral discharge, prostatic secretion)
-jerky movement, tear drop-shaped trophozoite
 Culture in culture medium
 Immunodiagnosis :
(Diamond’s medium)
ELISA, IFA
Treatment & prevention
• Metronidazole : 250 mg, 10 days
• treat both male & female (couple)
• hygiene education
- use of condom
- public toilet
- co-use utensil e.g. towel
Lab talk
Giardia lamblia
Trophozoite
Cyst
Dientamoeba fragilis
Trichomonad
T. hominis
T. tenax
T. vaginalis