PROTOZOANS - FLAGELLATES

Mastigophora

Subphylum of Flagellates

Cyst and Trophozoite stage

Life cycle of flagellates

Flagella

This is a whip-like organelle that is made up of flagellin.

False.

Some flagellates do not have cyst form, but all have trophozoite form.

True or False.

All flagellates have trophozoite and cyst form.

• Trichomonas spp.

• Dientamoeba fragilis

All flagellates have a cyst form except?

• Nuclear structure

• Undulating membrane

• Axostyle

• Number of flagella

Laboratory diagnosis of flagellates

Cercomonas intestinalis

The old name for Giardia lamblia

Old man’s eyeglasses

G. lamblia is morphologically known as?

Sucking disk (attachment)

G. lamblia virulence factor

The duodenum

G. lamblia is mainly confined in?

Malabsorption syndrome

What disease does G. lamblia cause?

G. lamblia

The only bilaterally symmetrical protozoan.

G. lamblia

This parasite is pear/ teardrop-shaped, has two nuclei, large karyosome, parabasal bodies, and axostyle.

8 flagella or 4 pairs

How many flagella does G. lamblia has?

Falling leaf

The motility of G. lamblia

G. lamblia cyst

This parasite has 2-4 nuclei, no peripheral chromatin, and cytoplasmic inclusions such as 2-4 parabasal bodies.

3 months

G. lamblia cyst can last up to how long in water?

• Stool

• Duodenal aspirates

• Upper small intestine biopsies

Specimen for G. lamblia

DS: Trophozoites and Cyst

IS: Cyst

Diagnostic and Infective stage of G. lamblia

Giardiasis

This disease is caused by G. lamblia, characterized by traveler’s diarrhea and steatorrhea

Metronidazole

Treatment for G. lamblia

Chilomastic mesnili trophozoite

This parasite is pear-shaped, has one large nucleus, shepherd’s crook appearance, and a characteristic spiral groove.

4 flagella (3 anterior, 1 within cytostme)

How many flagella does C. mesnili has?

Stiff-rotary (clockwise)

The motility of C. mesnili

• Chilomastic mesnili

• Mansonella Streptocerca

• Marburg virus

3 Shepherd’s crook appearance in Microbiology

C. mesnili cyst

This parasite has a lemon/ nipple shape appearance caused by a hyaline knob protrusion at one end.

Dientamoeba fragilis

This parasite is non-pathogenic and usually resides mainly in the mucosal crypts of large intestine.

Hitch Hiking (coinfection) Theory

An unproven theory that suggests that D. fragilis is transmitted via the eggs of helminth parasites such as Enterobius vermicularis and Ascaris lumbricoides.

Hakansson’s Phenomenon

It is when D. fragilis is mounted in water preparations, it swells and returns into its normal size unlike amebic trophozoite that swells and ruptures.

Iodoquinol or Tetracycline

Treatment for Dientamoeba fragilis

Dientamoeba fragilis trophozoite

This parasite is irregularly round, with 2 nuclei, containing 4-8 clumps of chromatin that are arranged symmetrically. It has fragmented nuclei, bacteria and vacuoles in the cytoplasm, and has progressive hyaline pseudopodia.

Enteromonas hominis

This parasite is oval, with 4 flagella (3 anterior, 1 within cytosome) and a jerky motility.

Enteromonas hominis

This parasite is elongated, with nuclei located on opposite ends, characterized by crossed eye cysts.

Intestine

Enteromonas hominis is usually found where?

Retortamonas intestinalis trophozoite

This parasite has 2 flagella that is U-shaped in the anterior with jerky motility.

Retortamonas intestinalis cyst

This parasite is lemon/ pear shaped with two fused fibrils anterior to the nuclear region, characterized by bird’s beak appearance.

Trichomonas vaginalis

The only pathogenic Trichomonas spp. because it is the most common cause of non-viral STI and usually seen in urine.

Trichomonas vaginalis

This parasite is pear-shaped, with undulating membrane of half its body length, 3-5 anterior flagella, and 1 posterior flagellum. It has a rapid, jerky motility.

Ping Pong disease

The disease cause T. vaginalis

Greenish yellow

In the disease caused by T. vaginalis, what is the color of the vaginal discharge?

Strawberry cervix

This is seen in T. vaginalis infection wherein there are red-punctate lesions upon examining vaginal mucosa.

Cervical carcinoma

T. vaginalis infection is connected to what type of cancer?

Vaginal discharge

Specimen of choice for T. vaginalis

• Sexual intercourse

• Vertical transmission

• Contaminated toilet seat

MOT of T. vaginalis

Metronidazole

Treatment for T. vaginalis

Trichomonas hominis

This parasite is seen in the intestine, the specimen is stool, and contaminated milk is the source of infection.

Trichomonas hominis

This parasite is pear-shaped with undulating membrane of full body length and nervous and jerky motility.

Trichomonas tenax

The smallest trichomonas spp.

Mouth esp. tartar between teeth or gingival margin of gums

Trichomonas tenax is seen where?

• Kissing

• Common use of contaminated dishes

MOT of Trichomonas tenax

Oral scrapings

Specimen of choice of Trichomonas tenax

Trichomonas tenax

This parasite is pear shaped, with undulating membrane of 2/3 of the body length, 4 anterior and 1 posterior flagella, thick axostyle beyond bod length, and small cytostome.