Intestinal Parasite I (PART 2) Flashcards
Enteric amoeba that lyses tissue
Entamoeba histolytica
Entamoeba histolytica:
- diseases
- Amoebic dysentery
- Amoebic colitis
- Amoebic abscesses
Entamoeba histolytica:
- Geographic distribution
world wide but higher incidence of infection in developing countries
Entamoeba histolytica:
- who are the hosts
humans are the only hosts
Entamoeba histolytica:
- infectious form
cyst
Entamoeba histolytica:
- how are cysts transmitted
fecal-oral rout
Entamoeba histolytica:
- test of choice for diagnosis
EIA - high sensitivity and specificity
Entamoeba histolytica:
- must be distinguished from ______ _______ and other protozoa and also must be distinguished from ________ ______!!!
- nonpathogenic amoebae
- polymorphonuclear neutrophils
Entamoeba histolytica:
- is morphologically indistinguishable from what two organisms
Entamoeba dispar
Entamoeba moshkovskii
How do you differentiate Entamoeba histolytica from Entamoeba hartmanni?
Exactly the same just much smaller
How do you differentiate Entamoeba histolytica trophs from Entamoeba coli trophs?
E. histolytica: Karyosome central and compact, perifpheral chromatin smoothly and evenly arranged “clean” cytoplasm
E. coli: Karyosome: off-center (messy looking), spread out, peripheral chromatin clumpy and unevenly arranged “dirty” cytoplasm
How do you differentiate Entamoeba histolytica cysts from Entamoeba coli cysts?
E. histolytica: Nuclei usually paired on each side in 2 different focal planes, chromatic bodies with rounded ends
E. coli: Nuclei scattered randomly throughout cyst in many different focal planes, chromatoid bodies with splintered ends
Only known pathogenic ciliate of humans
Balantidium coli
Balantidium coli:
- primary reservoirs
PIGS, rodents, and primates (infections are more common in areas where pigs are raised)
Balantidium coli:
- infectious form
cyst
Balantidium coli:
- What do we detect in the stool?
trophs seen, cysts not usually seen
Balantidium coli:
- appearance of trophs
CILIATED Big (40-200micrometers) cell with bean-shaped macronucleus, cytosome at narrower end
Balantidium coli:
- appearance of cyst
CILIATED, very large and round large kidney bean shaped macronucleus
What is one of the most common intestinal parasites in the world?
Giardia intestinalis
Giardia intestinalis:
- other names
G. lamblia
G. duodenalis
Giardia intestinalis:
- Geographic distribution
worldwide; more prevalent in warm climates and in children (daycare)
Giardia intestinalis:
- How is it transmitted?
fecal-oral rout, food, person to person
- FOMITES: inanimate objects
- WATERBORNE: most big outbreaks
Giardia intestinalis:
- common settings to see this kind of outbreak
- children in daycares
- campers and backpackers (drinking contaminated water)
Giardia intestinalis:
- infectious form
- what form comes out?
In: cyst
Out: cyst and troph
Giardia intestinalis:
- symptoms
diarrhea, bloating, nausea, malaise, foul-smelling feces and flatulence (purple burps)
Giardia intestinalis:
- Test of choice
EIA - high sensitivity and specificity
Giardia intestinalis:
- how often are the parasites in the feces?
varies from day to day (get 3 samples over period of 10 days)
Giardia intestinalis:
- what motility should you look for in a fresh specimen?
“falling leaf” motility
Giardia intestinalis:
- troph appearance
Troph: external flagella, pear shape; two nuclei (look like eyes) sucking disc, median bodies,
Giardia intestinalis:
- troops appearance
cyst: small oval cyst, two to 4 nuclei at one end, median bodies across middle, fibrils down center
