Chilomastix mesnili

[Chilomastix mesnili]

Causal Agents

Chilomastix mesnili, a nonpathogenic flagellate.

Life Cycle

The cyst stage is resistant to environmental pressures and is responsible for transmission of Chilomastix. Both cysts and trophozoites can be found in the feces (diagnostic stages) The Number 1 . Infection occurs by the ingestion of cysts in contaminated water, food, or by the fecal-oral route (hands or fomites) The Number 2 . In the large (and possibly small) intestine, excystation releases trophozoites. Chilomastix resides in the cecum and/or colon; it is generally considered a commensal whose contribution to pathogenesis is uncertain. Animals may serve as a reservoir for Chilomastix.

Geographic Distribution

Worldwide.

Clinical Presentation

Chilomastix mesnili is considered nonpathogenic. The presence of cysts and/or trophozoites in stool specimens can however be an indicator of fecal contamination of a food or water source, and thus does not rule-out other parasitic infections.

Chilomastix mesnili trophozoites, trichrome stain.

Chilomastix mesnili is a flagellated protozoan generally regarded as nonpathogenic in the human host. Trophozoites are pear-shaped and usually measure 6-24 µm in length. The anterior end is rounded and contains a single nucleus with an eccentric karyosome. The posterior end tapers off to a point.

Figure A: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure B: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure C: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure D: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure E: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure F: Trophozoite of C. mesnili from a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Chilomastix mesnili cysts, trichrome stain.

Figure A: Cyst of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure B: Cyst of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure C: Cyst of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure D: Cyst of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure E: Cyst of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Figure F: Cyst (lower) and trophozoite (upper) of C. mesnili in a stool specimen, stained with trichrome. Image taken at 1000x magnification.

Chilomastix mesnili cysts in wet mounts.

Figure A: Cyst of /em>C. mesnili in a concentrated wet mount of stool, stained with iodine. Image taken at 1000x magnification.

Figure B: Cyst of C. mesnili in a concentrated wet mount of stool, stained with iodine. Image taken at 1000x magnification.

DPDx is an education resource designed for health professionals and laboratory scientists. For an overview including prevention and control visit www.cdc.gov/parasites/.

Page last reviewed: May 3, 2016
Page last updated: May 3, 2016
Content source:
- Global Health – Division of Parasitic Diseases and Malaria
- Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.
Maintained By:
- Global Health

DPDx - Laboratory Identification of Parasitic Diseases of Public Health Concern

Chilomastix mesnili

Causal Agents

Life Cycle

Geographic Distribution

Clinical Presentation

Chilomastix mesnili trophozoites, trichrome stain.

Laboratory Diagnosis

Morphology

Treatment Information

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Chilomastix mesnili

Causal Agents

Life Cycle

Geographic Distribution

Clinical Presentation

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