protozoans Flashcards
What organisms are transmitted via contaminated food or water via an arthropod vector?
protozoans
malaria- arthropod vector
Infect the intestinal area or blood.
What are the four groups of parasites?
- Amoebas
- Flagellates
- Ciliates
- Coccidia (Malaria)
How can you identify the first three parasites?
Look for cyst form or troph form.
What is usually the infective form of parasites?
CYST form
TROPH form is usually not the infective form.
What is the general characteristic of cyst and troph forms?
Cyst form is non motile; Troph form is motile and feeding form.
What is the shape of cysts and trophs?
Cysts are normally round; Trophs may take on a variety of different shapes.
How many nuclei does a troph typically have?
Normally a troph will only have 1 nucleus.
What are the symptoms of amoebas?
Diarrhea and stomach pain.
What is Entamoeba Histolytica associated with?
Amoebic dysentery, which means blood in stool.
Where is Entamoeba Histolytica commonly found?
In tropic and subtropic regions.
What is the pathogenicity of Entamoeba Histolytica?
Depends on host and number of organisms seen.
What is a unique feature of Entamoeba Histolytica?
It is the only amoeba that ingests red blood cells.
What are the characteristics of the cyst form of Entamoeba Histolytica?
Regular even chromatin, centrally placed karyosomes, blunt shaped chromatin bar, and up to 4 nuclei.
What are the characteristics of the troph form of Entamoeba Histolytica?
Feeding form, irregular shape, 1 nucleus, and chromatin evenly placed.
What is Entamoeba dispar?
A non-pathogenic look-alike to E. histolytica.
DNA probes prove this
What distinguishes Entamoeba Hartmanni from Entamoeba Histolytica?
Differentiated through size; cyst < 10 um = Hartmanni.
hartmanni is a mini me of histolytica
What are the characteristics of the cyst form of Entamoeba Hartmanni?
Regular even chromatin, centrally placed karyosomes, blunt shaped chromatin bar, up to 4 nuclei, and smaller than E. histolytica!!!
What are the characteristics of the troph form of Entamoeba Hartmanni?
No ingested RBCs, 1 nucleus, and chromatin evenly placed with karyosome central
What is unique about Entamoeba coli?
It is larger than E. histolytica and pathogenicity depends on the number of organisms found.
What are the characteristics of the cyst form of Entamoeba coli?
Up to 8 nuclei, blunt and uneven chromatin, and eccentric karyosomes.
What are the characteristics of the troph form of Entamoeba coli?
Larger than E. histolytica, 1 nuclei
What is Endolimax nana?
Pathogenicity depends on how heavy the infection.
What are the characteristics of the cyst form of Endolimax nana?
Egg or oval shaped, up to 4 nuclei, and blotchy karyosomes, no peripheral chromatin
What are the characteristics of the troph form of Endolimax nana?
1 nucleus and blotchy karyosomes.
What are the characteristics of the cyst form of Iodamoeba butschlii?
Hallowed out glycogen vacuole and 1 nucleus.
What are the characteristics of the troph form of Iodamoeba butschlii?
1 nucleus and looks similar to E. nana (need cyst form to tell difference)
What is Blastocystis Hominis?
A debated pathogenicity organism, between fungus and parasite; granules along the side.
What is Nagleri Fowleri?
A brain amoeba causing primary amoebic meningoencephalitis.
ONLY troph stage seen but has both
How does Nagleri Fowleri infect humans?
Swims up the nose and enters the brain.
What is Acanthamoeba?
Causes chronic granulomatous encephalitis and is associated with homemade contact lenses.
What are the characteristics of the troph form of Acanthamoeba?
Cyst and troph forms; identification done by ophthalmologist by scraping corneal ulcer and placed on agar-agar with aliquot of heat killed/live e.coli
What are the general characteristics of flagellates?
They move by flagella; cyst is the infective form and diagnostic.
What is Giardia duodenalis?
The most common intestinal flagellate seen in the US.
CAUSES purple burps- lots of gas
seen in summer months
What are the characteristics of the cyst stage of Giardia duodenalis?
Bigger than yeast,
- football shape
-dividing structure called axoneme
-parabasal bodies
- 4 nuclei but typ, 2
What are the characteristics of the troph form of Giardia duodenalis?
Feeding form
-elongated shape
-2 nuclei with axoneme
-falling leaf motility
-common to see
-taper at end
-see flagella
What is Dientamoeba fragilis?
A flagellate with only troph stage; co-infects with pinworm
-hard to identify because degrades quickly once passed through stool
-symmetry of nuclei
What is Chilomastix mesnilii?
A small parasite with a pear or lemon-shaped cyst.
-usually not pathogenic
What are the characteristics of the cyst form of Chilomastix mesnilii?
Lemon shaped, 1 nucleus, and shepherd’s crook- cytostome
What is Trichomonas Vaginalis?
A sexually transmitted parasite that affects humans only.
ONLY troph stage
What are the symptoms of Trichomonas Vaginalis in women?
Itching, frothy discharge, and strawberry patch appearance in vaginal wall
What are the characteristics of the troph stage of Trichomonas Vaginalis?
Infective and diagnostic phase; motile with an undulating membrane.
motile helps with diagnose but if sits still will stop moving and look like WBC
What is Balantidium coli?
The only pathogenic ciliate to humans and the largest protozoan to infect man.
what does asymptomatic entamoeba histolytica look like?
shedding organism in the stool which they can pass on and affect others
what can severe infections of entamoeba histolytica look like
shed pieces of intestinal mucosa and get tumor like lesions with multiple diarrheic episodes per day
how can giardia be diagnosed
immunoassay. ELISA, multiple methods
What are the characteristics of the troph form of Chilomastix mesnilii?
oblong shape
nucleus moved to front or anterior
men symptoms of trichomonas vaginalis
urethritis and discharge; typ. asymptomatic
what may cause false + with leukocyte esterase test
trichomonas vaginalis
what is reservoir of balantidium coli
not sure, but thinking infected swine
balantidium coli cyst and troph form
macro and micro nucleus
balantidium coli only troph form
cilia only present in this stage- moving stage
