ameba Flashcards
unicellular organisms
Protozoans
Under protozoa:
Phylum Sarcomastigophora
Under Phylum Sarcomastigophora
- Sarcodina
- Mastigophora
- Ciliophora
- Apicomplexa
Now classified under fungi
Phylum Microsporidia
possess polar tube
Phlum Microsporidia
Spore forming microorganisms
Phylum Microsporidia
types of worms
- Phylum Aschelminthes
- Phylum Platyhelminthes
Types of Phylum Platyhelminthes
- Trematoda
- Cestoda
Types of reproduction of protozoans
- asexually
- asexually and sexually
Type of asexual reproduction of protozoans
- Binary Fission
- sporogony
Type of sexual reproduction of protozoans
- gametogony
Do not have cell walls
Protozoans
stucture inside the nucleus of protozoans
nucleolus or karyosome or endosome
The nucleus contain the ________
DNA
The karyosome contains the ________
RNA
2 regions of the cytoplasm
- endoplasm
- ectoplasm
Inner region of the cytoplasm that is for metabolic processes
Endoplasm (sol region)
Outer region of cystoplasm, important for protection, more clear (hyaline)
Ectoplasm (gel)
Protozoans that possess a pseudopod
Sarcodina (ameba)
Locomotor structure of ameba
pseudopodia
“false feet”
Inhabit the colon except for E. gingivalis
ameba
where can you find the E. gingivalis?
Mouth, oral cavity
Possess peripheral chromatin
Entamoeba
The nucleus of ameobas are ________
Vesicular
amebas are commensals except?
E. histolytica
Stages of development of amebas
- trophozoite
- cyst
vegetative stage of protozoans
trophozoite
feeding stage of protozoans
trophozoite
stage of protozoans that can be found in watery/Diarrheic stools
trophozoite
resisitant stage of protozoans
cyts
the infective stage of most protozoans
cyst
where kind of stool you can find the cyst stage of protozoans
Formed/watery stool
Mode of transmission of E. histolytica
Ingestion of Infective cyst
Is quadrinucleated
Infective cyst of E. histolytica
Habitat of E. histolytica
Large Intestine
FInal host of E. histolytica
Human
stages of infection of E. histolytica
- Ingestion of cyst
- Excystation in the smal intestine
- Metacyst
- Amoebulae/Metacystic Tropozoite
- Trophozoite in colon
- Encystation
- Precyst
- Cyst
- Cyst and/or Trophozoites present in stool
Once the ph of the small intestine becomes alkaline the cyst becomes the _________
Metacyst
Reproduction of Metacystic Trophozoite will become
Trophozoite
Can go to other internal organs
E. Histolytica
What other internal organs E. histolytica can go to?
Liver (most common), brain, lungs
Max nuclei of E. histolytica
4
The location of the karyosome of E. histolytica
centrally located
Structure of cyst that is fine and smooth in appearance, surounding the nucleus
Peripheral chromatin
cigar/sausage like, contain crystalline RNA, energy source
Chromidial body
Structures of E. histolytica cyst
- nucleus
- karyosome
- Peripheral chromatin
- Chromidial body
- glycogen vacuoles
movement of trophozoite of E. histolytica
- progressive
- unidirectional
Appearance of Pseudopodia of E. histolytica
Finger-like
Appearance of cytoplasm of E. histolytica
clean looking
presence of ingested red blood cell
trophozoite of E. histolytica
Appearance of rbc in unstained E. histolytica
greenish
In Disease Manifestations of E. histolytica, Majority of cases (90% of cases) are ______________
Asymptomatic Carrier State
In Disease Manifestations of E. histolytica, 10% of cases are ______________
Intestinal Disease
In Disease Manifestations of E. histolytica, <1% are ___________
Extraintestinal Disease
incubation period of Intestinal disease from E. hystolitica
1-4 weeks
Signs and symptoms of E. histolytica
- diarrhea
- dysentery (bloody diarrhea)
- abdominal pain
- flatulence
- weight loss
- chronic fatigue
- foul smelling stools
E. histolytica release ____________ to lyse mucosal lining
Enzymes
E. histolytica can cause the formation of __________
FLASK SHAPED ULCERS
Severe form of Diarrhea
Fulminating colitis
Clinical forms of Intestinal Amebiasis
● Dysentery
● Fulminating Colitis
● Amebic Appendicitis
● Ameboma; granuloma
may be mistaken for cancer (carcinoma)
Ameboma (granuloma)
Seen in chronic cases of amebiasis
Ameboma (granuloma)
Ectopic form of amebiasis
Extra-intestinal Disease
Extra-intestinal Disease due to E. histolytica can lead to ______________
Amebic liver abscess
Cardinal Signs of Amebic liver abscess:
○ Fever
○ Right Upper Quadrant
If you palpate it and it hurts it is ______
tender
Other signs of Amebic liver abscess include
Tender liver and hepatomegaly
enlargement of the liver
hepatomegaly
Extra-intestinal Disease that causes complication of dysentery
Cutaneous Amebiasis (Amebiasis cutis)
Extra-intestinal Disease that causes ulceration in the perianal area
Cutaneous Amebiasis (Amebiasis cutis)
Extra-intestinal Disease that causes rare manifestation of Entamoeba histolytica
Cutaneous Amebiasis (Amebiasis cutis)
Appearance of the liver aspirate:
Anchovy sauce
like
What can you find in the Liver aspirate from a patient with Amebic Liver Abscess (ALA)
Trophozoites
factors you have to
consider why it’s pathogenic
Virulence Factors
Pathology of E. histolytica
Ability to lyse tissue
Used by E. histolytica for attachment to the host cells
Lectin (Gal/GalNAc Lectin)
Lytic enzymes produced by the
parasite E. hystolytica that would lead to tissue destruction. Factor for the spread of the parasite
Cysteine Proteinases
Used by E. histolytica for formation of holes
Amebapores
bacterial dysentery
Shigella dysenteriae
More mucus and blood in stool
Bacillary Dysentery or Amebic Dysentery
Amebiasis
No granulocytosis (no high levels of WBC)
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
No high fever
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Seldom epidemic
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Gradual onset
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
No prodromal features
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
No vomiting
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Patient usually ambulant
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Bloody diarrhea
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Fishy odor stool
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
May be epidemic
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Acute onset
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Prodromal fever and
malaise common
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Vomiting common
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Patient prostrate
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Watery, bloody diarrhea
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Odorless stool
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Stool microscopy:
numerous bacilli, pus
cells,
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Stool microscopy:
numerous bacilli, pus
cells, macrophages, red cells,
no Charcot-Leyden
crystals
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Abdominal cramps
common and severe
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Tenesmus common
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Natural history:
spontaneous recovery
in a few days, weeks or
more; no relapse
Bacillary Dysentery or Amebic Dysentery
Bacillary Dysentery
Stool microscopy: few
bacilli, red cells,
trophozoites with
ingested red blood
cells, Charcot-Leyden
crystals
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Mild abdominal cramps
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Tenesmus uncommon
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Natural history: lasts for
weeks; dysentery
returns after remission;
infection persists for
years
Bacillary Dysentery or Amebic Dysentery
Amebic Dysentery
Ova and Parasite Examination:
Laboratory diagnosis
- Direct Fecal Smear (DFS)
- Concentration Techniques
- Permanent Stained Smear
Mababa detection pag DFS
Laboratory diagnosis
Direct Fecal Smear (DFS)
Demonstration of the trophozoite
Laboratory diagnosis
Direct Fecal Smear (DFS)
FECT — primarily for the recovery
of the cyst stages
Laboratory diagnosis
Concentration Techniques
Not yet conclusive
Laboratory diagnosis
Concentration Techniques
Confirmation of intestinal protozoans
Laboratory diagnosis
Permanent Stained Smear
Stains used for permanent stain smear
Laboratory diagnosis
Iron Hematoxylin
or Trichrome stain
Boeck’s, Rice Egg Saline, Diamond, Balamuth’s Egg Yolk Infusion, Robinson’s and Inoki
Laboratory diagnosis
Culture
Detection of antibodies
Laboratory diagnosis
Serology
specimen should be freshly passed stool
Laboratory diagnosis
Immunoassay
(ELISA), IHA
Laboratory diagnosis
Serology
Flask shaped ulcer may be seen
Laboratory diagnosis
Rectal Biopsy
Types of Laboratory diagnosis
● Ova and Parasite Examination
● Culture
● Serology
● Molecular Methods
● Rectal Biopsy
● Examination of Liver Aspirates
High Risk Groups of E. histolytica
○ Men who have sex with men (MSM)
○ Food handlers
○ Poor access to clean water
E. histolytica is More Prevalent in ______________
- Tropics
- Poor developing countries
“E. histolytica look-alikes”
- E. dispar
- E. moshkovskii (Laredo strain)
- E. bangladeshi
Entamoeba that Prefers lower temperature
(25-30 C)
E. moshkovskii (Laredo strain)
used to differentiate the lookalikes
- Molecular techniques
- Isoenzyme analysis
Manner of reporting of E. histolytica when found under the microscope:
Entamoeba histolytica/dispar
Treatment for E. histolytica
- Metronidazole
- Diloxanide Furoate
- Iodoquinol
Treatment for E. histolytica for Asymptomatic carriers
Diloxanide Furoate
Prevention E. histolytica
○ Proper Disposal of Waste
○ Proper Sanitation
○ Access to safe water and food
○ Development of an effective vaccine
Cause of non-pathogenic ameoba
fecally contaminated water
max nuclei of E. coli cyst
OTHER COMMENSAL AMEBAE
8
location of karyosome E.coli cyst
OTHER COMMENSAL AMEBAE
Eccentric
Prominent & larger karyosome
OTHER COMMENSAL AMEBAE
Entamoeba
coli cyst
The Peripheral chromatin of E. coli cyst is _____
OTHER COMMENSAL AMEBAE
course/rough
Chromatoidal bars
of E. coli cyst are
OTHER COMMENSAL AMEBAE
Needle-like; splintered; broomstick;
witchbroom
What has larger trophozoite? E. coli or E. histolytica
OTHER COMMENSAL AMEBAE
E. coli
Movement of E.coli trophozoite
OTHER COMMENSAL AMEBAE
sluggish;
non-progressive
Pseudopodia of E. coli
OTHER COMMENSAL AMEBAE
Blunt
Cytoplasm of E. coli is :
OTHER COMMENSAL AMEBAE
- Dirty looking
- Has ingested bacteria; yeast
Small race of E. histolytica
OTHER COMMENSAL AMEBAE
Entamoeba
hartmanni
Movement of Entamoeba hartmanni Trophozoite
OTHER COMMENSAL AMEBAE
Sluggish and non-progresive
Ameba of pigs and monkeys
OTHER COMMENSAL AMEBAE
Entamoeba
polecki
Most common parasite in Papua
New Guinea
OTHER COMMENSAL AMEBAE
Entamoeba
polecki
Chromotoidal bar of Entamoeba polecki
OTHER COMMENSAL AMEBAE
angular/pointed
location of karyosome in Entamoeba polecki
OTHER COMMENSAL AMEBAE
center
Max nucleus of Entamoeba polecki (troph & cyst)
OTHER COMMENSAL AMEBAE
1
Movement of Entamoeba polecki
OTHER COMMENSAL AMEBAE
progressive
Peripheral chromatin is evenly distributed
OTHER COMMENSAL AMEBAE
Entamoeba
polecki
Morphologically similar to E. polecki
OTHER COMMENSAL AMEBAE
Entamoeba
chattoni
Seen in apes and monkeys
OTHER COMMENSAL AMEBAE
Entamoeba
chattoni
Smallest intestinal amoebae (as
small as RBC)
OTHER COMMENSAL AMEBAE
Endolimax
nana
Shape of Endolimax nana cyst
OTHER COMMENSAL AMEBAE
Oval
Max nuclei of Endolimax
nana cyst
OTHER COMMENSAL AMEBAE
4
No peripheral chromatin
OTHER COMMENSAL AMEBAE
Endolimax nana
Location of Endolimax nana karyosome
OTHER COMMENSAL AMEBAE
Eccentric
due to the location of the karyosome of Endolimax nana cyst
OTHER COMMENSAL AMEBAE
Cross eyed cyst
max nucleus of Endolimax nana Trophozoite
OTHER COMMENSAL AMEBAE
1
Endolimax nana Trophozoite movement
OTHER COMMENSAL AMEBAE
non progressive manner
Ameba of swine (pigs)
OTHER COMMENSAL AMEBAE
Iodamoeba
butschlii
Uninucleated with a large eccentric karyosome; with achromatic
granules
OTHER COMMENSAL AMEBAE
Iodamoeba
butschlii
karyosome of Iodamoeba
butschlii appearance
OTHER COMMENSAL AMEBAE
“Basket of flowers”
Large glycogen vacuole
OTHER COMMENSAL AMEBAE
Iodamoeba
butschlii
Iodamoeba butschlii Trophozoite movement
OTHER COMMENSAL AMEBAE
Sluggish movement
Ameba of oral cavity (gum line)
OTHER COMMENSAL AMEBAE
Entamoeba
gingivalis
No cyst stage
OTHER COMMENSAL AMEBAE
Entamoeba
gingivalis
This is the first amebae described in humans
OTHER COMMENSAL AMEBAE
Entamoeba gingivalis
MOT of Entamoeba
gingivalis
OTHER COMMENSAL AMEBAE
person to person
Max nucleus of Entamoeba
gingivalis trophozoite
OTHER COMMENSAL AMEBAE
1
location of karyosome in Entamoeba gingivalis
OTHER COMMENSAL AMEBAE
-Centrally located karyosome
Fine peripheral chromatin
OTHER COMMENSAL AMEBAE
Entamoeba
gingivalis
Entamoeba
gingivalis is capable of ingesting what?
OTHER COMMENSAL AMEBAE
WBC
Entamoeba gingivalis is seen in patients with __________
OTHER COMMENSAL AMEBAE
pyorrhea alveolaris
Scavengers and eat debris; can ingest WBCs, debris, RBC (rare)
OTHER COMMENSAL AMEBAE
Entamoeba
gingivalis
Found inhabiting the gum line of
teeth, tartar and gingival pockets of teeth of unhealthy mouths and even healthy mouths; may also be seen in genital tract
OTHER COMMENSAL AMEBAE
Entamoeba
gingivalis
Appropriate specimen for Entamoeba gingivalis
OTHER COMMENSAL AMEBAE
mouth scrapings
Found inhabiting lakes, pools, tap water, air conditioning units and heating units (facultative
parasites)
FREE LIVING PATHOGENIC AMEBAE
FREE LIVING PATHOGENIC AMEBAE:
○ Acanthamoeba
○ Balamuthia
○ Naegleria
Most pathogenic FREE LIVING PATHOGENIC AMEBAE
Naegleria
Parasitic stage of FREE LIVING PATHOGENIC AMEBAE location
Central Nervous System
Naegleria fowleri Belongs to Family _________
Vahlkampfiidae
Free Living Amoeboflagellate
Naegleria fowleri
Trophozoite stage of this parasite has ameba and flagellate form
Amoeboflagellate
The cyst of Naegleria fowleri can only be found in the ________
environment
able to resist high temperatures
thermophilic
thermophilic parasites
Naegleria fowleri cysts
stage of Naegleria fowleri that can be recovered on humans
Trophozoite
Feeding form, “Limax” form of Naegleria fowleri
Ameboid (ameba)
Swimming form of Naegleria fowleri
Ameboflagellate (flagellate)
Naegleria fowleri Entry into the body
Olfactory Epithelium, respiratory tract, Skin and Sinuses
When the Naegleria fowleri reach the CNS it can cause the disease called _____________
Primary Amebic Meningoencephalitis
(PAM)
Diagnostic stage of Naegleria fowleri
Trophozoite
Matter of reproduction of Naegleria fowleri
Promitosis
stage of Naegleria fowleri with presence of two anterior flagella
Flagellated stage
Max nucleus of Naegleria fowleri trophozoite
1
No peripheral chromatin
Naegleria fowleri trophozoite
In Primary Amebic Meningoencephalitis
(PAM), Once the symptoms
appears, the patient
would die after ______
7 days
Signs and symptoms of Primary Amebic Meningoencephalitis
(PAM)
○ Headache
○ Fever
○ Rhinitis
○ Lethargy
○ Olfactory problems
○ Mental confusion and
coma
Rish factors of Primary Amebic Meningoencephalitis
(PAM)
Swimming in
contaminated pools lakes and rivers
Incubation period of Rish factors of Primary Amebic Meningoencephalitis
2-3 days or as long as
1-2 weeks
Pathogenic
Determinant of Primary Amebic Meningoencephalitis
(PAM)
- PRESENCE OF Amebostomes
- Cytopathic Effect on Host Tissues
food cups, used to attach
to the surface of the cell
Amebostomes
Amebostomes release what?
phospholipase
Naegleria fowleri Cytopathic Effect on Host Tissues
● Secretion of lytic enzymes
● Membrane Pore-forming proteins
● Induction of apoptosis
● Direct feeding of the ameba
Diagnosis:
- Wet mount examination of CSF
- Smears stained with Wright’s or Giemsa
- Biopsy
- CSF Analysis
- Culture (Bacteria Seeded Agar
Culture)
- Molecular Methods
Primary Amebic Meningoencephalitis
(PAM)
What can you see in patient’s with Primary Amebic Meningoencephalitis
(PAM) - Wet mount examination of CSF
Decreased CSF glucose, Increased protein; High WBC
Used in Culture (Bacteria Seeded Agar
Culture) for diagnosis of PAM
Modified Nelson’s
Medium
Usually diagnosis of PAM is done ____________
Post mortem
Treatment &
Prevention for PAM
- Amphotericin B With Clotrimazole
- New Agents: Azithromycin;
Voriconazole
Morphologically similar to Naegleria fowleri but biochemically distinct species present in the country
Naegleria
philippinensis
Acanthamoeba spp. Belongs to Family ____________
Acanthamoebiadae
Acanthamoeba spp. types:
- Acanthamoeba castellani
- A. culbertsoni
- A. hutchetti
- A. polyphaga
- A. rhysoides
Free-living Ameba
Acanthamoeba spp.
Characterisitc Feature of Acanthamoeba spp
Presence of Acanthapodia
spine like pseudopodia; spine like appearance
Acanthapodia
Entry point of Acanthamoeba spp
- Nose
- Eyes
- Broken skin
difference of Acanthamoeba spp to Naegleria fowleri
slower progression
Infective stage of Acanthamoeba spp
IS: cyst or trophozoite
Unique characteristic of Acanthamoeba spp cyst
Double wall
Outer wall of Acanthamoeba spp cyst
wrinkled
Inner wall of Acanthamoeba spp cyst
polyhedral
max nucelus of Acanthamoeba spp Trophozoite
1
Acanthamoeba spp Trophozoite have presence of _________
contractile vacuole
Acanthamoeba spp causes?
- Granulomatous Amebic Encephalitis
- Amebic Keratitis
- Cutaneous lesions
Incubation period of Granulomatous Amebic
Encephalitis
10 days
Chronic; slow progression
Granulomatous Amebic
Encephalitis
Patients will experience this after getting GAE
- meningitis
- Encephalitis
- presences of granulomas lesions
Common among debilitated or
immunocompromised patients
Granulomatous Amebic
Encephalitis
Affects the eyes,
ulcerations sa cornea
Amebic Keratitis
Mistaken for herpes keratitis
Amebic Keratitis
Implicated among contact lens
users
Amebic Keratitis
Appropriate specimen for Amebic Keratitis
Corneal Scrapings
Presence of hard erythematous
nodules or skin lesions
Cutaneous lesions
Cutaneous lesions ussualy seen in ___________
AIDS patients
Diagnosis:
● Biopsy
● Corneal Scrapings
● Culture
● Molecular Methods
Amebic Keratitis
Used in culture for Acanthamoeba spp.
○ Culberto’s medium
○ Non nutrient medium
with Gram (-) bacteria
Treatment for Amebic Keratitis
- Fluorocystine
- ketoconazole
- amphotericin B
Very Fatal once cerebral manifestations
appear
Amebic Keratitis
Prevention of Amebic Keratitis
Boil water/prolong
heating of water can
kill the parasite
Acanthamoeba is more
resistant to ______________
chlorine
disinfection
Acathamoeba can be a
possible reservoir for:
- legionella
- myobateria
- Gr(-) bacilli
Balamuthia mandrillaris Family _____________
Leptomyxidae
Balamuthia mandrillaris is recognized as a new species causing ____________
Amebic
meningoencephalitis
Associated with GAE
Balamuthia mandrillaris
Trophozoite of Balamuthia mandrillaris characteristics
branching
Cyst of Balamuthia mandrillaris characteristics
Wavy
Other free living ameba that causes amebic encephalitis:
● Sappinia diploidea
● Hartmannella vermiformis
Considered now as opportunistic
Hartmannella vermiformis
