Week 2: Intestinal Protozoa Flashcards
Amoeba
-Motile via pseudopod
-Troph: motile, reproducing, feeding, live in lower GI tract
-cyst: infective stage, nonmotile, non-feeding stage
stool consistency vs protozoan forms
Liquid stool = higher trophozoites
formed stool = higher cysts
ID the following
Id the following parasite
Troph size >12um
Cyst size >10um
Entamoeba histolytica/dispar
Symptoms: diarrhea, flatulence, cramping
Transmission: cyst/troph passed in feces -> mature cysts ingested
size: 10-20um
Nuclear app: small central karysome w/ even chromatin
cysts: 1,2, or 4 nuclei w/ cigar shaped - rounded chromatid bars
Trophs: 1 nuclei w/ cytoplasm “ground glass” & may have RBCs
-Amebic colitis or invasive interstitial amebiasis (mucosa is invaded)
-extraintestinal amebiasis
-if RBC is present = NOT dispar
-Dispar = non-pathogenic (NOT cause harm)
-morphologically identical to E. histolytica
In lab report as = “entamoeba histolytica/ dispar”
Lab diagnosis
-Microscope O&P exam
-immunodiagnosis: Ab/Ag detection
-molecular
How to improve detections with microscopy?
3 stool samples over 10 days
-measure size & observe internal characteristics
what are the non-pathogenic amoeba
-entamoeba Hartmanii
-entamoeba coli
-endolimax nana
-lodamoeba buetshlii
Id the following
Troph size <12 um
Cyst size <10um
Entamoeba hartmanii
symptoms: **
Transmission: cyst/troph passed in feces -> mature cysts ingested
size: 5-10um
Nuclear App: small central karysome w/ even chromatin
Cyst: 1,2 or 4 nuclei w/ cigar shaped body + round edges
Troph: 1
Id the following
Entamoeba coli
symptoms: ***
Transmission: cyst/troph passed in feces -> mature cysts ingested
size: 10-35um (~15-25)
Nuclear app: eccentric karysome w/ irregular chromatin
cyst: 1-8 nuclei, w/ spliter shaped, pointed, rough edged
trophs: 1 nuclei, w/ food vacuoles & ingested bacteria
Id the following
Endolimax nana
size: 5-10um (~6-8)
Nuclear app: large irregular clumped karysome w/no peripheral chromatin
cysts: 1-4 nuclei
troph: 1 nuclei
Id the following
lodamoeba buetshlii
size: 5-20 (~10-12)
Nuclear appearance: large irregular karyosome w/no peripheral chromatin
cysts: 1 large glycogen vacuole (inclusion)
trophs: No cytoplasmic inclusions
Id the following
Blastocytis hominis
size: 5-30 (~8-10)
Nuclear app: 1 nuclei but 2-4 may be present at the rim of cytoplasm
-cell contains large central body/ vacuole w/ thin band/ rim of cytoplasm
-unicellular parasite of UNCLEAR pathogenic potential that colonizes the intestines of humans and a wide range of non-human animals.
ID the following examples
Artifacts
-Epithelial and white blood cells are often seen in trichrome-stained stool smears and may be mistaken for amebae.
-yeast, pollen spores, plant material, fungi, Miscellaneous
what are the intestinal flagellates & ciliates
Flagellates
-Giardia duodenalis (lamblia/intestinales)
-Chilomastix mesnilli
-Dientamoeba fragilis
Ciliate
-Balantidium coli
Id the following
Giardia duodenalis cyst form
size: 8-19 (~10-14)
Nuclear app: mature nuclei have 4, immature have 2
-Cytoplasm contains central axonemes
-Flagella may be seen
-live in duodenum & jejunum
Lab diagnosis
-ID cyst/trophs in O&P exam
-Multiple exams & may need to exam duodenum contents
-direct immunofluorescence DFA
-enzyme immunoassay
-rapid immunochromatographic cartridges
Id the following
Giardia duodenalis troph form
size: 10-12 x 12-15
Nuclear app: 2 nuclei
-cytoplasm w/ central axonemes
-8 flagella
-median parabasal bodies
-live in duodenum & jejunum
-attach to mucosa w/ suctorial discs
Lab diagnosis
-ID cyst/trophs in O&P exam
-Multiple exams & may need to exam duodenum contents
-direct immunofluorescence DFA
-enzyme immunoassay
-rapid immunochromatographic cartridges
Id the following
Dientamoeba fragilis - troph form only. No cyst stage
size: 9-12um
Nuclear app: 60-70% have 2 nuclei
-No flagella seen
-kayrosome usually in clusters of 4 or 8
-no peripheral chromatin
ID the following
Chilomastix mesnili - cyst form
-non-pathogenic
size: 6-10um, lemon shaped
Nuclear app: 1 nuclei
-round body w/ one knob
-diagnostic curved cytostomal fibril
ID the following
Chilomastix mesnili - troph form
-can be confused with giardia due to flagella
size: 10-15 x 3-10 um
Nuclear app: 1 eccentric nucleus @ the “top”
-Pear shaped pyriform
-4 flagella
Id the following
Balantidium coli - cyst form
size: 50-70um
Nuclear app: 1 large kidney shaped nucleus & 1 micronucleus
-may see cili under cell wall
-cyst seen less frequently
Id the following
Balantidium coli - troph form
size: 50-100 x 40-70
Nuclear app: 1 large kindey shaped nucleus & 1 micronucleus
-ciliated
-cytoplasm w/ vacuoles
Practice
:)
what are the intestinal coccidia
- cystoisospora/ isospora belli
- cryptosporidium
- cyclospora
-may need special stain to visualize
-has sexual phase, asexual phase & may have 2 different hosts
Difference between sporozoites & oocytes in parasitology
Sporozoites are formed within oocysts. Parasite produces spore-like cells called sporozoites that are able to enter different tissues. These cells develop inside parasite-made structures called oocysts
Id the following
Cryptosporidium
size: 4.2-5.2um
-stool concentrated in mucus flecks
-autoinfective due to Asexual reproduction
-resistant to chlorine & ozone
Lab diagnosis
-Need modified acid-fast stain for positive ID/ definite diagnosis (trichrome stain = inadequate)
-immunoassays: DFA (fluo-stain), enzyme immunoassay
-molecular
Id the following
Cyclospora cayetanenesis
size: 7.5-10um
-mostly found in summer of tropical/subtropical areas of the U.S.
-Humans only major host
- need 1-2wks outside body to mature/ be infective
Lab diagnosis
-Need modified acid-fast stain for positive ID
-will autofluoresce under UV microscrope
-Molecular
ID the following
Cystoisospora belli (Isospora belli)
SIZE: 25-30um
-found worldwide tropical/subtropical areas & least common to infect humans
-immunocrompromised Pts may have profuse nonbloody diarrhea, weakness, anorexia & weight loss
Lab diagnosis
-ID oocytes in stool
-ID by wet mount/ acid-fast
-Autofluoresce under UV light
Practice
:)
