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Organism Index (A-Z)

Chilomastix mesnili (Nonpathogen)

Organism:
This organism belongs to the flagellates, is a nonpathogen, and causes no disease.  Both the trophozoite (usual size, 6-24 µm long and 4-8 µm wide) and cyst forms (usual size, 6-10 µm long and 4-6 µm wide) can be found in clinical specimens.

chilo1 chilo2 chilo3 chilo4
Trophozoites
Cyst in iodine
Cyst, permanent stain

Life Cycle:
Intestine, organisms passed in feces

Acquired:
Fecal-oral transmission via cyst form; contaminated food and water

Epidemiology:
Worldwide, primarily human-to-human transmission

Clinical Features:
None.

Clinical Specimen:
Intestinal:  Stool

Laboratory Diagnosis:
Intestinal:  Ova and Parasite examination (concentration, permanent stained smear)

Organism Description:
Trophozoite:  Pear shaped, 1 nucleus and distinct oral groove (cytostome); flagella are rarely seen without special stains.
Cyst:  Pear or lemon shaped, will contain 1 nucleus; the cytostomal fibril is curved and is called the “shepherd’s Crook”.

Laboratory Report:
Chilomastix mesnili (indicate trophozoites and/or cysts)

Treatment:
None

Control:
Improved hygiene, adequate disposal of fecal waste, adequate washing of contaminated fruits and vegetables

Comments:
Small organisms can mimic other small protozoa.