Endolimax nana is a species of amoeba that is commonly found in the intestines of humans. It was originally considered non-pathogenic, but some studies suggest it can cause diarrhea. E. nana trophozoites range in size from 5 to 12 micrometers and have a single nucleus. Cysts are spherical to ellipsoid shaped and range from 4 to 12 micrometers, usually containing 1 to 4 nuclei. The life cycle involves ingestion of cysts which excyst in the small intestine, the trophozoites multiply and produce more cysts which are passed in feces. Infections are usually asymptomatic, and diagnosis is by stool examination. Treatment is generally not needed as E.

1. Endolimax
nana
Prepared by: Veronica
Baje

2. Endolimax
nana
• Endolimax is a genus of amoebozoa that
are found in the intestines of various
animals, including the species E. nana
found in humans. Originally thought to be
non-pathogenic, studies suggest it can
cause intermittent or chronic diarrhea.
Additionally, it is very significant in
medicine because it can provide false
positives for other tests, notably the
similar species Entamoeba histolytica, the
pathogen responsible for amoebic
dysentery, and because its presence
indicates the host has consumed fecal
material.

3. Trophozoites
• Vary in size from 5 to 12μm.
• The average trophozoite size range is 7 to 10μm.
• Sluggish, nonprogressive motility, which is
accomplished by blunt, hyaline pseudopods.
• Single nucleus may or may not be visible in
unstained preparations.
• Karyosome is large and irregularly shaped.
• Blotlike appearance.

4. Cysts
• Spherical, ovoid, or ellipsoid cysts
• Measures 7 to 10μm in size.
• Some cysts may measure a mere 4μm, whereas
others may be as large as 12μm.
• There may be one to four nuclei in an E. nana
cyst, the most commonly seen form is the
mature cyst that contains 4 nuclei.

6. Life Cycle
• Cysts are typically found in formed stool,
whereas trophozoites are typically found
in diarrheal stool. Intestinal colonization
with nonpathogenic amebae occurs after
ingestion of mature cysts in fecally
contaminated food, water, or fomites.
• Excystation occurs in the small intestine
• and trophozoites are released, which
migrate to the large intestine. The
trophozoites multiply by binary fission
and produce cysts, and both stages are
passed in the feces

7. Clinical
Symptoms
• E. nana infections are usually asymptomatic.

8. Laboratroy
Diagnosis
• The laboratory diagnostic
technique of choice for identifying
E. nana trophozoites and cysts is
stool examination.

9. Treatment • E. nana is considered a nonpathogen.
Treatment is generally not indicated.