amoeba lec Flashcards
- subphylum and class of amoeba
- classification of amoebas
subphylum: sarcodina
class: lobosea
extraintestinal spp:
Entamoeba histolytica
Entamoeba hartmanni
Entamoeba coli
Entamoeba polecki
Endolimax nana
lodamoeba bütschlii
intestinal spp:
Entamoeba gingivalis
Naegleria fowleri
Acanthamoeba species
they are considered the simplest form of animal life and are very sensitive to changes in their environment
protozoa
- single celled microorganism
- some r pathogenic while others r not
why is an amoeba named after the Greek word
amobile
- Because it constantly changes shape in response to its environment.
[They change shape and form protective structures when conditions like pH and humidity change.]
What are pseudopodia?
“False feet” used by Sarcodina amoebas for movement and capturing food.
what are cilia and flagella used for
cilia:
short, hair like structures used for movements in ciliophora protozoa
flagella:
movement in mastigophora; they are long whip-like structures
what are the 2 types of amoebas based on habitat
intestinal amoeba (lives inside intestines)
free-living amoeba (lives in soil or water).
what are the structures and organelles of protozoa
- nucleus
- karyosomes (nucleolus/ endosome)
- a mass inside the nucleus
- types of nucleus:
vesicular n - Karyosomes are suspended in nucleoplasm. (Examples: Entamoeba histolytica, Entamoeba coli, Endolimax nana)
compact n - Dense chromatin-filled karyosome with little nucleoplasm. (Example: Balantidium coli) - cytoplasm
- interior of the cell containing organelles
- 2 portions
ENDOPLASM:
Dense, granular, contains mitochondria, Golgi apparatus, endoplasmic reticulum (ER), microsomes, and stored food.
ECTOPLASM:
Less granular, involved in locomotion, food acquisition, respiration, excretion, and protection. - locmotion organelles
- pseudopodia
- flagella
- cilia
Contains chromosomes essential for life, reproduction, and genetic transmission.
nucleus
difference between vesicular nucleus and compact nucleus
Vesicular Nucleus
The karyosome (a small mass inside the nucleus) is floating in a fluid-like nucleoplasm.
The nucleus looks less dense and more transparent under a microscope.
Compact Nucleus
The karyosome is tightly packed with chromatin (genetic material), making the nucleus dense and dark-looking.
There is very little space (nucleoplasm) inside.
[Vesicular Nucleus → Has more space inside, looks lighter.
Compact Nucleus → Densely packed, looks darker.]
Temporary, finger-like projections used by amoebas for movement and food acquisition.
pseudopodia
Whip-like projections found in Zoomastigophora, originating from the kinetoplast (parabasal bodies + blepharoplast).
flagella
- the internal portion attached to the kinetoplast is called the axoneme.
[In Zoomastigophora (a group of protozoa), flagella come from a special structure called the kinetoplast. The kinetoplast is made up of:
Parabasal bodies – Help with energy and movement.
Blepharoplast – The part where the flagellum is attached and starts growing.]
Numerous short projections found in Ciliophora, arising from basal granules in the ectoplasm and covering the parasite’s body.
cilia
difference between the stages of development of amoebas
trophozoites:
- feeding stage (parasite aquired nutrient from the source)
- asexual
- vegetative stage (multiplying - occurs by binary fission)
- pseudopods
- invasive stage
- delicate
cyst:
- non feeding stage (not moving much, non motile)
- sexual
-infective stage (MOT is fecal oral route)
- cell wall
- dormant stage
- thick cell wall (protects cysts to continue its life cycle)
- sensitive yung T whereas C is resistant to envi factors. thus, able to last up for many moths/ years
Types of encystation
Protective encystation -no morphological, changes. For survival
Reproductive encystation- nucleus multiplies within the cyst = multiply daughters upon encystation
What disease can u get from E.histolytica
Intestinal amebiasis
Amoebic colitis
Amebic dysentery
Extra-intestinal amebiasis
Amebic liver abscess (ALA -
Most common disease)
Difference between pinocytosis and phagocytosis
Pinocytosis: The cell “drinks” liquids and small dissolved molecules. It forms tiny vesicles to absorb fluids.
Phagocytosis: The cell “eats” large particles like bacteria or food particles. It forms bigger vesicles to engulf solid objects.
What does the cyst of E. Histolytica produce
4 daughter organism called metacystic trophozoites
It has for a number of years been primarily considered a parasite of pigs and monkeys
Entamoeba polecki
- human infections are relatively rare
Has a ground glass cytoplasm
Endolimax nana
This is often found in areas when E. Coli is present
Endolimax nana
Non pathogenic but may be mistaken for pathogenic amoebas in fecal samples
Iodamoeba butschlii
What is the distinguish feature of the Entamoeba gingivalis
Ingested white blood cells
These ar intestinal commensal with a fecal oral transmission route
Endolimax nana
Iodamoeba butschlii
It is found in the oral cavity which spreads through direct contact and does not form cysts
Entamoeba gingivalis
What is the habitat of Naeglaria fowleri and for Acanthamoeba spp.
- Fresh water and moist soil
- Enters through skin, eyes, lungs or genito-urinary tract
What does N. fowelri and Acantamoeba spp cause
- PAM, primary amebic meningoencephalitis
Death occurs within 3-6 days
No effective treatment - Granulomatous amebic meningoencephalitis
A rapid fatal brain infection with symptoms like headache, fever, stiff neck and coma
PAM
- kernig’s sign
A chronic brain infection with headache, seizures, altered mental status and necrosis
Granulomatous amebic memningoencephalitis
- no effective drug for this disease
Eye infection linked to contact Lens use
Acanthamoeba keratitis
What are the 3 forms of naegleria fowleri
Ameboid trophozoites
Flagellate form
Cysts
What is needed for the identification of N. fowelri
Immunoperoxidase
Immunofluorescent staining
- as morphologi identification is difficult
What are the standard procedures detecting amoebas
Direct saline wet prep
- motile amoebic trophozoites
Direct iodine wet prep
- enhance protozoan cysts
Permanent slides
What triggers encystation and excystation
ENCYSTATION
food scarcity
Accumulation of metabolic waste
pH changes
Loss or water
Oxygen imbalance
Overpopulation
EXCYSTATION
osmotic changes in the environment
Enzymatic action on the nervous cyst wall
Favorable pH
Hot tissue enzymes
