Amoeba (in general) Flashcards
what Sub/Phylum is characterized by the presence of hyaline foot-like extrusions from the cytoplasm?
Phylum Amoebazoa
or Subphylum Sarcodina
All amoeba inhabits the large intestine except what?
Entamoeba gingivalis
E. gingivalis inhabits the mouth/oral cavity
what do you call the hyaline foot-like extrusions of the cytoplasm?
pseudopodia
it is a cortical zone of undifferentiated cytoplasm and a locomotory structure
Protozoans may reproduce asexually through ____, and sexually
binary fission
A nucleus of a protozoan may have what in its structure?
- karyosome
- varying peripheral chromatin
All Entamoeba are lumen-dwelling except?
Entamoeba gingivalis
All Entamoeba are non-pathogenic or commensals except what?
Entamoeba histolytica
Cyst is the infective stage of Entamoeba except for?
Entamoeba gingivalis
2 regions of cytoplasm of protozoans
- Ectoplasm
- Endoplasm
region of cytoplasm for metabolism and nutrition
Endoplasm
Endo = loob
region of cytoplasm that is characterized as hyaline structure for protection
Ectoplasm
from here stems the pseudopodia
4 stages in the life cycle of protozoans
- Trophozoite
- Precyst
- Cyst
- Metacystic stage
most observed are trophz and cysts stage
this is the motile or vegetative state of protozoans
Trophozoite
trophozoites are seen in what type of stool sample?
fresh watery, loose, or mucus-filled stool sx
basta remember na basa & fresh, higher chances of trophz
stains used to visualize trophozoite and its nucleus
buffered Methylene Blue (either Nair’s or Quensel’s)
what do u call the characteristic of trophozoites that make them easy to break?
labile hehe
what do you call the nonmotile stage of protozoans?
Cyst
Infective stage of protozoans is called
Cyst
- Immature cyst: pre-cyst
- Mature cyst: metacyst
In what type of stool will you observe cysts?
Formed stool sx
as stool is formed, less trophozoites
What are the possible stains that can be used for protozoan cysts?
Lugol’s Iodine or D’Antoni’s Iodine
Iodine cannot be used sa trophz bcoz it is toxic
cysts have a structure called chromatid bodies and these serve as their what?
nutrient source or energy source kung san k masaya
MOT of Entamoeba histolytica
ingestion of infective cyst
Habitat of Entamoeba histolytica
Large Intestine
Entamoeba histolytica is known as the only true ____
pathogen
or pathogenic amoeba
Infective stage of Entamoeba histolytica
mature cyst
metacyst
Virulent stage of Entamoeba histolytica
Trophozoite
how many nucleus does the infective stage of Entamoeba histolytica have?
4
karyosome location of Entamoeba histolytica
central
both troph and cyst gitna
cysts have centrally-located karyosomes but usually eccentric
Peripheral Chromatin of Entamoeba histolytica
Fine, evenly distributed
Entamoeba histolytica cytoplasm appearance
- clean-looking cytoplasm (troph)
- thin wall, hyaline appearance (glassy), highly refractile
Chromatoidal bar shape of Entamoeba histolytica cyst
Cigar-shaped or sausage-shaped
The trophozoite of Entamoeba histolytica may contain ingested what? And it’s exhibiting a property called?
Ingested RBCs; hematophagia
trophz w/ ingested RBCs are termed hematophagous
motility of Entamoeba histolytica troph
Unidirectional, progressive
Virulence factors of Entamoeba histolytica
- Lectin
- Amoebapores
- Cysteine Proteinases
Virulence factor of Entamoeba histolytica responsible for attachment
Lectin, GalNac Lectin, or Gal Lectin
Virulence factor of Entamoeba histolytica responsible for holes on lining of large intestine
Amoebapores
Virulence factor of Entamoeba histolytica for tissue disruption and spread of infection
allows parasite to penetrate mucosa and adhere to underlying layer
Cysteine Proteinases
How do we diagnose Entamoeba histolytica?
- DFS
- Conc techniques
- Culture media
- Stains
- Serology (antibody detection)
Concentration techniques applicable to Entamoeba histolytica
- FECT/FEACT
- MIF
Stains used for Entamoeba histolytica
- Iron Hematoxylin
- Trichome stain (more used nowadays)
Serological tests done to Entamoeba histolytica
- ELISA - histolytica vs other kamukha
- IHAT
- IFAT
- ELISA = Enzyme-linked Immunosorbent assay
- IHA/IHAT = Indirect Hemmagglutination
- IFAT = Indirect Fluorescent Antibody Test
Treatment for Entamoeba histolytica
- Metronidazole - for symptomatic
- Diloxanide furoate - asymptomatic
Where does the excystation of Entamoeba histolytica occur?
excystation = “exit” cyst stage to become troph
small intestine
no excystation occurs in an acidic envi; requires neutral pH or slightly alkaline envi
After excystation into four trophozoites, where will the Entamoeba histolytica trophz multiply? what do u call that process of reproduction?
Large Intestines; binary fission
Entamoeba histolytica trophozoites will invade the mucosal crypts of the intestinal lumen where they feed on RBCs and form ulcers. Ulceration of the intestinal wall may give rise to?
Amoebic dysentery
characterized by mucus and blood in stool
If Entamoeba histolytica trophozoites invade the Colon, what are the diseases that may manifest?
- Colitis (inflammation)
- Amoebic Appendicitis
- Ameboma
- Colitis may lead to perforation and secondary bacterial peritonitis
- Amoebic dysentery too
what do you call the most common extraintestinal form of amoebiasis and is characterized by anchovy sauce liver aspirate where u can find trophz?
Amoebic Liver Abscess
ALA gg kapag asa liver na
ALA may rupture into the pericardium then pleura then intraperitoneal rupture
If lumala pa, Entamoeba histolytica may travel into the brain and cause what disease?
Secondary Amoebic Meningoencephalitis
why 2ndary? primary kasi is Naegleria fowleri
True or False
no treatment is necessary for commensal amoeba
True
they do not cause disease
Which amoebae are morphologically the same with Entamoeba histolytica except for size?
E. dispar, E. moshkovskii, & E. hartmanni
Considered as smaller version of Entamoeba histolytica
Entamoeba hartmanni
MOT of Entamoeba coli
Ingestion of infective cyst from contaminated water/fud
Entamoeba coli troph number of nucleus?
one
Entamoeba coli cyst nucleus number?
8
octonucleated
karyosome of Entamoeba coli
Eccentric & Large
Peripheral chromatin of Entamoeba coli
Coarse, rough, unevenly distributed
Cytoplasm of Entamoeba coli trophozoite
dirty-looking; granular
marumi kasi may debris, bacteria, even yeast. ingests everything lmao
In terms of size, which is bigger, Entamoeba coli or Entamoeba histolytica?
Entamoeba coli
is the cystic wall of Entamoeba coli thick or thin?
thick
the pseudopodia of Entamoeba coli troph appears what?
blunt, wider
the chromatoidal bar of Entamoeba coli appears as what?
Broom stick/Witch broom/Splinter-shaped
motility of Entamoeba coli trophozoite
Sluggish, non-directional, non-progressive
motility of Entamoeba hartmanni
Sluggish, non-progressive
Amoeba of pigs and monkeys; also the most common parasite in Papua New Guinea
Entamoeba polecki
Entamoeba polecki’s infection is classified as what type?
can be passed from animals to humans*
Zoonotic
Entamoeba polecki trophozoite number of nucleus
1
Entamoeba polecki cyst nucleus number?
1
Entamoeba polecki karyosome location?
Centrally located (both tropz & cyst)
Entamoeba polecki chromatoidal bar appearance
Angular/pointed appearance
motility of Entamoeba polecki troph?
Unidirectional, progressive, sluggish
what organism is morphologically identical to Entamoeba polecki?
Entamoeba chattoni
the smallest intestinal amoebae that is as small as a RBC is called?
RBC = 6-8um
Endolimax nana
Endolimax nana trophozoite number of nucleus?
1
Endolimax nana cyst number of nucleus
4
karyosome of Endolimax nana trophozoite
Large, Irregular
karyosome of Endolimax nana cyst
Large, prominent, blot-like
Appearance of Endolimax nana cyst
Oval, cross-eyed
motility of Endolimax nana trophz
Unidirectional, non-progressive, sluggish
Cysts of Entamoeba are usually ____ than those of Endolimax or Iodamoeba
larger or smaller
larger
amoeba that is also known as the amoeba of swine (pigs)?
pigs onli no monkeys
Iodamoeba butschlii
nucleus number of trophz and cyst of Iodamoeba butschlii
one
True or False
Peripheral chromatin is only present in Entamoeba
True
Nucleus appearance of Iodamoeba butschlii trophz & cysts
“Basket of flowers” appearance
this is due to achromatic granules
Iodamoeba butschlii has a ____ vacuole sa cytoplasm
glycogen
- cyst = one glycogen vacuole
- trophz = plenty of vacuoles
motility of Iodamoeba butschlii troph
sluggish, nonprogressive
what do u call the amoeba of the oral cavity?
Entamoeba gingivalis
True or False
Entamoeba gingivalis has no cyst stage
true
MOT of Entamoeba gingivalis
kissing, sharing of personal items
Entamoeba gingivalis is non-pathogenic but can be seen in patients with ____ (gum infections)
pyorrhea alveolaris
nucleus number of Entamoeba gingivalis troph
1
remember na rin na fine & evenly distributed peripheral chromatin (tinatamad na q)
what parasite is referred to as the “brain-eating amoeba”?
Naegleria fowleri
Naegleria fowleri belongs to the family Vahlkampfiidae in which members are characterized as what?
able to temporarily assume a flagellate form while being completely devoid of flagella in the ameboid stage
ameboflagellates
has an amoeba and flagellate form
True or False
Naegleria fowleri thrives best in cold weather
False
Naegleria fowleri is thermophilic
meaning, it thrives best in warm aquatic environments
what form or life stage of Naegleria fowleri is only found in the environment?
cyst
Free-living amoeba are what type of parasites?
Facultative
with a free-living and parasitic phase
the infective stage of Naegleria fowleri is what?
trophozoite
Naegleria fowleri may enter the body through?
olfactory epith or skin or nose
but usually nose. then penetration of the nasal mucosa tapos lalapit sa olfactory nerves tapos cribriform plate tapos olfactory bulb tapos arachnoid space tapos brain GG
Naegleria fowleri trophozoites replicate by?
promitosis
Promitosis is a primitive intranuclear mitosis that can be seen in protistans. It is characterized by the absence of asters, poorly defined chromosomes, a large, constricting and dividing nucleoli and the presence of a karyosome
motility of Naegleria fowleri troph?
sluggish, directional
by blunt and broad pseudopodia
however, eong flagellated form wld have a spinning or jerking motility
Naegleria fowleri causes what type of disease in the brain?
characterized by inflammation of meninges in the brain
Primary Amoebic Meningoencephalitis
PAM
Incubation period of PAM
2-3 days or 1-2 weeks
px usually dead after 1 week
Naegleria fowleri trophozoite can be distinguished from other cells by their ____ shape and progressive mvmnt
limax
Latin, sluglike
Lab Diagnosis for Naegleria fowleri
- Wet Mount Examination of CSF
- Smears stained with Wright’s or Giemsa
- Biopsy
- CSF Analysis (neutrophilic dominance, high prot, low gluc)
- Culture
- Molecular methods
Treatment drug for Naegleria fowleri
Amphotericin B with Clotrimazole
New agents: Azithromycin, Voriconazole
Acanthamoeba spp. and Balamuthia mandrillaris have two life cycle stages. what are they?
Trophozoite and Cyst
Acanthamoeba spp. and Balamuthia mandrillaris are causative agents of what disease in the brain?
usually associated with immunocompromised hosts
Granulomatous Amoebic Encephalitis
GAE
True or False
GAE is also associated with swimming like Naegleria fowleri infection and invasion of the CNS is secondary to infection anywhere else in the body
False
GAE is not associated w/ swimming
When Acanthamoeba enters the eye, what may occur?
severe keratitis
or Acanthamoeba keratitis
what disease is associated with the use of improperly disinfected soft contact lenses?
Acanthamoeba keratitis
nucleus number of Acanthamoeba trophozoite & cyst
one
Karyosome of Acanthamoeba spp troph
Centrally-located, densely-staining
Karyosome of Acanthamoeba cyst
Large, Central
what do you call the thorn-like appendages of Acanthamoeba trophozoite which is used for locomotion and in evident on phase-contrast microscope?
Acanthapodia
these are spring projections of the pseudopod
An Acanthamoeba cyst has two walls. An outer wall and an inner wall. what are the characteristics of each wall?
- Outer: wrinkled
- Inner: polygonal
If Acanthamoeba enters through skin, what disease manifest?
cutaneous lesions
- these are presense of hard erythematous nodules
- common in AIDS patients
Acanthamoeba diagnosis
- usually after death
- biopsy
- corneal scrapings
- culture
- molecular methods
culture used for detection of Acanthamoeba?
Cubertson’s medium
Cubertson’s is a non-nutrient medium with Gram-negative bacteria (usually Escherichia coli) kasi nga Acanthamoeba eats gram-negative bacteria
Treatment for Acanthamoeba
- Fluorocystine
- Ketoconazole
- Amphotericin B
True or False
Balamuthia mandrillaris has the same appearance with Acanthamoeba
True