(P) Lab 1: Parasitic Amoeba Flashcards
PPT ni sir Rupert-based
Organisms
- Entamoeba histolytica
- Endolimax nana
- Entamoeba coli
- Iodamoeba butchslii
+ E. hartmanni
unicellular organisms and the lowest form of animal life
protozoa
Two morphologic form of ameba life cycle:
Cyst & Trophozoite
the form that feeds, multiplies and posses pseudopods
tropho
non feeding stage
cyst
the morphologic conversion from the CYST form into the TROPHOZOITES form
Excystation
conversion of TROPHOZOITES to CYST.
encystation
Laboratory Diagnosis
- Saline wet prep
- Iodine wet prep
- permanent stains
exhibits rapid, unidirectional, progressive movement with the help of finger-like hyaline pseudopods.
Entamoeba histolytica: Cyst
Classification of the Amoebas
- Intestinal
- Extraintestinal
Variants of karyosome include eccentric or fragmented
karyosomal material
E. histolytica (tropho)
Nucleus contains a small central mass of chromatin known as a karyosome (also known as karyosomal chromatin)
Entamoeba histolytica: Trophozoites
histolytica
surround the karyosome of the trophozoite
Peripheral Chromatin
Contains a fine granular cytoplasm, often referred to as ground glass in appearance
E. histolytica Tropho
E. histolytica trophozoite
E. histolytica trophozoite
no. of nuclei
1
E. histolytica
Non-motile
Cyst
E. histolytica
1-4 nuclei
Cyst
E. histolytica
Small and central karyosome
Both
E. histolytica
Fine and evenly distributed peripheral chromatin
Both
E. histolytica
Chromatoid bars, Rounded ends in young cysts, Diffuse glycogen mass in young cysts
Cyst
E. histolytica
Diagnosis
Coproculture: Direct fecal smear
Concentration methods: Formalin Ether Concentration test, Merthiolate Iodine Formalin Concentration
Culture: Robinson’s and Inoki medium
Serology: IHAT, CIE, AGD, IFAT, ELISA
Microscopic Diagnosis
using this visualization of trophozoite motility will
be seen
DFS, with NSS,
Microscopic Diagnosis
Concentration methods (2)
Formalin Ether Concentration TEST
Merthiolate Iodine Formalin Concentration Test
Diagnosis
Culture
Stool’s culture using Locke’s egg serum
Diagnosis using serology tests, except:
1. Indirect hemagglutination (IHAT)
2. Counter Immunoelectrophoresis (CIE)
3. Agar gel diffusion (AGD)
4. Immunoenzyme test (IT)
5. Enzyme-linked immunosorbent assay (ELISA)
4 (dapat Indirect fluorescent antibody test (IFAT))
- Which of the following structures is (are) typical in trophozoites of
E. histolytica?
A. Single nucleus with a small karyosome
B. Unevenly distributed peripheral chromatin
C. Chromatoid bars
D. Glycogen mass
A
E. histolytica infection is traditionally diagnosed by finding which of
the following?
A. Adult and egg forms of the parasite in a suspected stool sample
B. Trophozoites and/or cysts in a suspected stool sample
C. Larvae in a suspected CSF sample
D. Adult form of the parasite in suspected tissue sample
B
The infective stage of E. histolytica is which of the following?
A. Trophozoite
B. Cyst
B
the only species pathogenic to man while others are non-pathogenic or commensals
E. histolytica
1.
inhabits the oral cavity, indicating poor oral hygiene
Entamoeba gingivalis
E. histolytica
The ingested cyst passes through the stomach and then, into the?
the small intestine
has a cosmopolitan distribution, and the prevalence is higher among countries with tropical and/or subtropical climate than temperate regions
E. histolytica
parasite is a lumen - dweller that mainly inhabits the cecum
E. histolytica
E. histolytica
The parasite becomes very active, breaks out of the cyst, and multiplies through
binary fission
has a very acidic medium but becomes neutral or alkaline at the later part, which is where excystation occurs
Small intestine
E. histo
Each mature cyst produces 4 daughter organisms called?
metacystic trophozoites
which in turn multiply continuously through binary fission resulting into a colony.
E. histo
As the content of the colon moves towards the rectum, water is absorbed thus making the feces more solid. The parasite, at this point, undergoes?
encystation as the feces transits the large intestine
excreted with the feces is the infective stage to other persons for as long as it remains viable
cyst
E. histolytica
incubation period
1-4 months
E. histolytica
biologic incubation period
2-5 days or longer
E. histolytica
Some infected individuals, called carriers, may remain asymptomatic for several years and since their stool contains infective cyst, they are also referred as?
cyst passers
E. histolytica
most common habitation site of E. histolytica; slower or more turbulent flow of contents than the other parts, thus favoring colonization
cecum
E. histolytica
Trophozoites move actively from one place to another by means of a?
pseudopodium
E. histolytica
secrete lytic enzymes that can lyse tissues (histolytica – meaning lysis of cells
tropho
The lytic enzymes and activity of the pseudopodia cause trophozoites to produce lysis of the intestinal wall
E. histolytica
relatively resistant to such digestion causing the organisms to extend the intestinal ulcers sideward resulting to flask-shaped ulcer, the typical lesion of amoebic ulcer.
muscular layer of the intestine
Trophozoites can, also, cause irritation of the intestinal wall causing increase peristalsis and secretion of significant amount of mucus resulting to mucoid-watery stools
E. histolytica
E. histolytica
an erode blood vessels causing blood to ooze into the feces thus, production of bloody-mucoid diarrhea
Migrating trophozoites
Occasionally, trophozoites in the intestinal tract may stimulate proliferation of fibrous tissue resulting to formation of granuloma referred as?
amoeboma
may be mistaken for a tumor or malignant growth
E. histo
Overtly active trophozoites can pass through the walls of the intestinal tract allowing them to gain access to other organs resulting to?
extra-intestinal amoebiasis
From the cecum, trophozoites can reach distant sites through lymphatics, blood vessels (hematogenous route), via?
direct extension
most common site of extra-intestinal amoebiasis
liver
Lysis of liver cells results to an
abscess
Liver exudate contains
trophozoites, pus cells and digested liver cells
not seen in the exudates since encystation does not take place in the tissues
cyst
Diagnotic feature of the cytoplasm
ingested RBC
A. Centrally located karyosome
B. Bullseye karyosome
C. Both
D. NOTA
C
Diagnostic feature of this
Cigar-shaped or with rounded ends
may be seen in the cytoplasm
E. histolytica (cyst)
- a commensal parasite that inhabits the cecum
- distributed worldwide and more prevalent in warm that cold climates
- Life history is like that of Entamoeba histolytica
- presence in human feces indicates that there has been fecal contamination of the foods and/or drinks thus placing the individual into the risk of acquiring illnesses that are fecal borne in nature
Entamoeba coli
Diagnostic feature
MULTIPLE PROMINENT
NUCLEI
E. coli (cyst)
Describe the chromatoidal body
splintered ends, with jagged-ends, or appear like whiskbroom
E. coli cyst
A. Cytoplasm is dirty-looking due to ingested food particles.
B. Cytoplasm is dirty-looking due to ingested bacteria.
C. Cytoplasm is dirty-looking due to ingested food particles and bacteria.
C
E. coli (cyst)
Describe cytoplasm
dirty-looking
vacuoles that contain ingested food particles as well as bacteria
E. coli tropho
TOF. Laboratory diagnosis for E. coli includes the demonstration of cyst and/or trophozoite in fecal smears WITHOUT stain.
T (w/out stain)
large race (>10um) pertains to?
Entamoeba histolytica,
small race (<10um) pertains to?
Entamoeba hartmanni
widely distributed but more cases are in tropical- and sub- tropical regions of the world
ENTAMOEBA HARTMANNI
TOF. The incidence of infection for E. hartmanni is higher in communities with high incidence of Entamoeba coli infection.
T
Stage of E. hartmanni
Trophozoite
Motility
sluggish and
slightly directional
E. hartmanni
Stage
E. hartmanni cyst
Diagnostic feature
rice grains
E. hartmanni
A. Large eccentric karyosome
B. Vesicular
C. Fine chromatin granules
B
A. food particles and bacteria
B. ingested RBC
C. both
A
A. Bacilliform
B. Cross-eyed apperance
C. Both
C
Endolimax nana cyst
Diagnostic feature
GROUND GLASS APPEARANCE
Parasite
Endolimax nana cyst
A. motility: slug-like
B. organ: long pseudopodia
C. NOTA
A
Endolimax nana
trophozoite
Parasite
Endolimax nana
trophozoite
Size of the glycogen mass
2/3rd or 1/2
Iodamoeba butchslii cyst
Surrounded by chromatin granules called?
perikaryosomal
chromatin granules
Iodamoeba butschlii
trophozoite
a harmless commensal of the human intestine that inhabits the cecum
Iodamoeba butchslii, E. nana, E. coli
parasite
existing in the trophozoite form only
ENTAMOEBA GINGIVALIS
inhabit the oral cavity
ENTAMOEBA GINGIVALIS
E. gingivalis
Morphology is similar with the trophic forms of E. histolytica and E. nana.
TOF
F (histo & coli)
It is primarily recovered from _________ pockets between teeth and gums and in tonsillar crypts
pyorrhea
E. gingivalis
Red blood cells are very rarely seen in its cytoplasm. Most frequently, it ingests fragments of?
leukocytes
TOF. E. gingivalis is known for its great ability to ingest white cells and/or fragments of its nucleus.
T
It is usually found associated with a non-pathogenic flagellate
Trichomonas tenax
inhabits the oral cavity, some oral fusiform bacteria, and oral moniliasis (caused by Candida albicans)
Trichomonas tenax
E. gingivalis is, oftentimes, associated with what infection?
Actinomyces infection