non pathogenic intestinal amoeba

1. Non-pathogenicIntestinal
Amoebae
Ekta Gupta

2. Introduction
 Amoeba is a single- celled protozoa that
constantly changes its shape.
 The word “amoeba” is derived from the greek
word “amoibe” meaning “change”. They
constantly change their shape due to presence of
an organ of locomotion called as “
pseudopodium”.

3. Amoebae can be classified in two
ways-
 Based on habitat: amoebae are classified as:
1. Intestinal amoebae (reside in large intestinal): they
comprise of both pathogenic (e.g. E. histolytica) and
nonpathogenic amoebae.
2. Free living amoebae: they are widely distributed in
soli and water.
 Taxonomical classification: amoebae are classified
taxonomically based on molecular structure(ribosomal
RNA)

4. Non-pathogenic amoebae
1. E. coli
2. E. hartmanni
3. E. gingivalis
4. E. polecki
5. Endolimax nana
6. Iodamaeba butschlii

6. 1. Entamoeba coli
 E. coli is a non-pathogenic amoeba
the colonizes the large intestine.
 The life cycle is similar to E.
histolytica
 It also has three forms-
(1) Trophozoite
(2) Precyst
(3) Cyst
 It is frequently found in the stool
samples of healthy individuals and
should be differentiated from that of
E. histolytica.

7. Differences between Entamoeba histolytica and E. coli
E. histolytica E. coli
Trophozoite
Size 15-20 μm 20-25
Motility Very active sluggish
Cytoplasm RBC, WBC, tissue
debris, bacteria
Except RBC
Nucleus Small Large
Precyst
10-20 μm 20 μm
Cyst
Size 12-15 μm 15-25 μm
Nucleus small large
Nuclei 1-4 in number 1-8
Chromatoid body Thick with rounded ends Filamentous and thread
like ends

8. 2. Entamoeba hartmanni
 It is also known as small race variant of histolytica, i.e.
morphologically it is similar to E. histolytica but of
smaller size;
 Trophozoite: 8- 10 um
 Cyst is 6-8 um
 Nonpathogenic
 Colonizes the large Intestine

9. 3. Entamoeba gingivalis
 It is the 1st parasitic amoeba of humans to be
described; recovered from the soft tarter between the
teeth.
 Only Trophozoite stage exists
 It is recovered from vaginal secretions of women who
use intrauterine devices

10. 4. Entamoeba polecki
 It is a non-pathogenic amoeba usually found in the
intestine of pigs and monkeys.
 However, human infection is rare
 The trophozoites measure 10–12 μm size
 motility nonprogressive and sluggish (like E. coli)
 Cyst is of 5–11 μm size

11. 5. Endolimax nana
 It is a small (nana means small) non-pathogenic
amoeba.
 It is worldwide in distribution, frequently resides in the
large intestine of humans and other animals.
 Trophozoite measures 8–10 μm in size
 Sluggish type of motility
 Cyst is 6–8 μm in size
 Nucleus (both trophozoite and cyst)

12. 6. Iodamoeba butschlii
 It is also worldwide in distribution though less
common than E. coli and E. nana
 Trophozoite is 12–15 μm in size
 Cyst measures 10-12 μm

14.  https://www.youtube.com/watch?v=aNpgTIjwJ
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 https://www.youtube.com/watch?v=lYs6kfHcU
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 https://www.youtube.com/watch?v=uFlsKZM2
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15. Thank you