(L4) AMOEBAS I Flashcards
Kingdom: Subkingdom: Phylum: Superclass: Order: Family: Genus:
Protista Protozoa Sarcodina Rhizopoda Amoebida Endamoebidae Entamoeba, Iodamoeba, Endolimax
Have small karyosomes near or at the center of the nucleus
ENTAMOEBA
Peripheral chromatin granules line the nuclear membrane
ENTAMOEBA
Delicate achromatic threads connect the karyosome to the nuclear membrane
ENTAMOEBA
Have a relatively large karyosome of irregular shape
ENDOLIMAX
Thin layer of peripheral chromatin which is inconspicuous
not clearly seen
ENDOLIMAX
Several achromatic threads connect the karyosome to a delicate nuclear membrane
ENDOLIMAX
Have a relatively large karyosome rich in chromatin (also called an endosome) surrounded by a single layer of periendosomal granules that attach to the karyosome and nuclear membrane by radiating achromatic threads
IODAMOEBA
IODAMEOBA:
Have a relatively large karyosome rich in chromatin (also called an \_\_\_\_\_\_\_) surrounded by a single layer of \_\_\_\_\_\_\_ that attach to the karyosome and nuclear membrane by radiating achromatic threads
endosome, periendosomal granules
is the only pathogenic amoeba
E. histolytica
is the only amoeba found in the oral cavity
E. gingivalis
Non-pathogenic Mouth Amoeba
Entamoeba gingivalis
Pathogenic Intestinal Amoeba
Entamoeba histolytica
→ Contain chromatoidal bars (crystallized ribonuclear proteins)
→ Contain glycogen vacuoles
→ Most have smooth, rounded walls and may have more than 1 nucleus
Amoeba Cyst
crystallized ribonuclear proteins
Chromatoidal bars
→ Contain bacteria, food
particles, and ingested RBCs
→ Show motility
→ Most trophozoites are
irregular in shape and
uninuclear
Amoeba Trophozoite
Entamoeba fall into 3 groups according to the number of nuclei in the mature cyst:
E. polecki - 1 (pigs and monkeys)
E. histolytica - 4
E. coli - 8
Entamoeba that has no encysted form
E. gingivalis
Entamoeba are natural parasites of the alimentary tract of man, monkeys, and many species of vertebrate and invertebrate hosts except
E. moshkovskii
is a free-living amoeba found in polluted water sources
E. moshkovskii
Entamoeba are exclusive lumen dwellers, except
E. histolytica
can survive in extraintestinal environment
E. histolytica
Entamoeba gingivalis is also known as
Atrial Amoeba
The first parasitic amoeba of man to be described
Entamoeba gingivalis
Exhibit progressive directional movement in
freshly made wet mount due to its multiple
pseudopodia
Entamoeba gingivalis
Entamoeba gingivalis:
Motility: Nucleus: Karyosome: Cytoplasm: Inclusions:
Motility: pseudopodia may be long and lobose
or short and blunt
Nucleus: spherical with distinct nuclear membrane lined with closely packed chromatin granules
Karyosome: near the center; small and welldefined with delicate achromatic threads
extending to the nuclear membrane
Cytoplasm: exhibits a definite zone of
demarcation between the clear ectoplasm and the more granular endoplasm
Inclusions: endoplasm contains numerous food vacuoles containing phagocytized and partly digested leukocytes and epithelial cells, and at times, bacteria and (rarely) RBCs
Nuclear fragments of ______ are usually
recognizable in stained specimens which serve to identify Entamoeba gingivalis
leukocytes
E. gingivalis:
Mode of transmission
oral direct contact like kissing, droplet spray, or eating utensils
E. gingivalis:
Habitat
Oral cavity, gingival pockets near the base of the tooth
E. gingivalis:
Prevention
proper care of teeth and gums
Infective stage and Diagnostic stage of E. gingivalis
Trophozoite
Amoeba that can be demonstrated of trophozoites in material or scrapings removed from the gingival margin of the gums, from between the teeth or dentures, or from the soft tartar of the teeth
E. gingivalis
_______ trophozoites may appear larger than E. histolytica or E. dispar
E. coli
E. coli Trophozoites
Motility: Nucleus: Peripheral chromatin: Karyosome: Cytoplasm: Inclusions:
Motility: sluggish, non-directional (due to its
broad, short, blunt, and granular pseudopodia)
Nucleus: spherical with thick nuclear membrane (the nucleus is not easily visualized; unstained preparation has better visibility than stained ones)
Peripheral chromatin: clumped and unevenly arranged on the membrane
Karyosome: large, irregularly shaped, eccentrically located
Cytoplasm: granular with little to no differentiation into ectoplasm and endoplasm; endoplasm is vacuolated
Inclusions: bacteria, yeast, and other debris
E. coli cysts:
Nuclei
Macture cyst:
Immature Cyst:
Macture cyst: 8 nuclei
Immature Cyst: 1-4 nuclei
Diagnostic and Infective stages of Entamoeba coli:
Mature cysts and trophozoites
Diagnostic and Infective stages of Entamoeba coli:
Mature cysts and trophozoites
The excystic form is also known as a
metacyst
E. coli:
The mature trophozoites multiply by binary fission and produce cysts through
encystation
E. coli:
Mode of transmission
ingestion
E. coli
Habitat:
lumen of the large intestine (cecum)
E. coli
Diagnosis
Stool exam:
• Diarrheic/dysenteric/liquid → trophozoite
• Semi-formed → trophozoite and/or cyst
• Formed → cyst
- dwarf intestinal slug
- One of the smaller non-pathogenic amoeba
- Has a worldwide distribution and occurs as commonly as E. coli
→ Shows more nucleic variation than any other amoeba
Endolimax nana
E. nana cyst
Nucleus:
Mature:
Immature:
Mature: 4 nuclei
Immature: 1-2 nuclei
E. nana
Habitat
Lumen of the large intestine (cecum)
E. nana
Diagnosis:
stool exam
Iodamoeba buetschlii are also known as
Iodine Cyst of Wenyon
Has a worldwide distribution, but its acquisition rate is not as high as that of E. coli and E. nana
Iodamoeba buetschlii
Iodamoeba buetschlii:
Mode of transmission
ingestion of food or drink
contaminated with mature cysts
Iodamoeba buetschlii:
Habitat:
lumen of the large intestine (cecum)
Currently, the name ______ is used to designate true pathogens and _________ is used to designate non-pathogens
E. histolytica , E. dispar
