Cryptosporidiosis Flashcards
Cryptosporidium is classified in the phylum ….
Apicomplexa (apical rings,
micronemes and subpellicular microtubules)
all parasites in the apicomplexa group are reffered as …
conccicia
The species of coccidia develop where q
in the gastrointestinal tract of
vertebrates include Eimeria, Isospora, Cyclospora, and Cryptosporidium.
apicomplexa species that develop extra intestinal include what ….
Neospora, Sarcocystis, and Toxoplasma.
true or false: most Cryptosporidium Species infect what
humans
c parvis oocyst shed by
cattle
c parvis is infective to
Cattle
Cat
Goat
Sheep
Rat
Human
Dog
Pig
Rabbit
Mice
what does Cryptosporidiosis
cause
diarrheal outbreaks
who are most at ristk for Cryptosporidiosis
kids and immunosupressed
Cryptosporidium parvum:
A threat to….
the quality of surface water and the environment
Cryptosporidium: Excystation requires reducing conditions,
pancreatic enzymes, bile salts—-Release of…..
4 sporozoites
Differentiation into spherical trophozoites — develop into….
Type 1 meronts (schizonts) that
contain 6 -8 merozoites.
Type 1 merozoites invade nearby cells and develop into…..
Type 2 meronts or into
trophozoites to complete the asexual cycle
* Merozoites similar in morphology and function to the sporozoites
Type 2 merozoites differentiate into…
male microgamonts or female macrogamonts.
-Male microgamonts release microgametes that can
fertilize macrogametes inside the female macrogamonts.
Generation of 2 types of oocysts….
-Thin-walled auto-infectious oocysts (20%)
-Thick-walled oocysts (80%) shed in stool
how big are the oocysts
4-6um wide
what are the oocysts made up of
Composed of tough environmentally resistant wall
enclosing 4 sporozoites – resistant to disinfections
true or false crypto is opportunistic and extracellular
false it is intracellular
what does crypto infect
Infects gastrointestinal and respiratory epithelial cells
what is quirky about the oocyst crypto walla
unique suture. atthe end
The suture dissolves during
excystation, opening the wall to…
4 sporozoites
Colonization of the … of the
small intestine by
Cryptosporidium
villi
c.parvum oocysts are viable in
§ Potassium dichromate
§ Chloroform
§ Ether
§ Ammonia
§ Sodium hydroxide
§ Buffered hypochlorite
§ Potassium permanganate
c parvum oocysts are killed bu
§ Freezing
§ Boiling for 30 mins
§ Hydrogen peroxide
§ Ozone (limits: Kitchener-Waterloo outbreak)
§ Oo-cide (Ammonia + sodium hydroxide + biocide)
true. orfalse: Sporozoites and merozoites of c parvum appear similar to those of other coccidias with
the same organelles.
true
what are the organelles of c parvum
the rhoptries, micronemes, electron dense granules,
nucleus and ribosomes.
what does. cparvum does not have
do not have polar rings, mitochondria and micropores.
what are microneme
are rod-like structures. Micronemal proteins are important in host celll ocalization, gliding motility and ligand-receptor attachment to host cells. Several classes of
proteins are associated with micronemes: GP900, TRAP-C1, CpSCRP and ABD reactive protein
microneme might secrete their protein through ….
the rhoptry duct
what are rhoptroed
-are club-shaped membrane-bound organelles.
-C. parvum have single rhoptry. -Rhoptryproteins are involved in transforming the hostcell membrane into a parasitophorous vacuoles
(PV) membrane
what are dense granules involved in
in host cell modification following the invasion. DG proteins are released from the parasite surface into the
PV
transmission of c parvum
The infection is transmitted by the fecal-oral route via the oocyst stage.
true or false: c parvum lacks host specificity
true
groups. at risk for c parvum
-workers like vets and farmers
-immunodeficient peeps
Analysis of Water Samples for the Presence of Oocysts
- At least 50 litres of water must be
filtered (1µ porosity) - Wash the filter with water
- Centrifugation
- Staining
- Microscope
what is the efficacy to analysis. ofwater samples for the presence. of oocysts
6.3%
true or false: we still get outbreaks. of Cryptosporidium
yeah
-most recent in sweden
what was the cause of the 1988 crypto outbreak
a pool
what happened in 1993
-crypto outbreak
-wisconsin
-403 000 people aka 25% of peeps
-cause by waterworks
-100-fold increase of C. parvum oocysts found in the water treatment plant
what were the main symptoms of the 1993 milwaukee crypto outbreak
Diarrhea, fever, abdominal cramps and
vomiting were the main symptoms
how many people died in the 1993 crypto outbreak
54
How do Cryptosporidium species interact with the host?
- Initial interaction via
receptors
– CSL ( C parvum sporozoites
ligand)
– CP47 - Attach by anterior
pole
– Invagination
– Microfilamentdependent - Causes damage to apical surface of cell
crypto in birds infects what
respiratory tract
crypto infects what in fish and reptiles
intestinal tract
crypto infects what in immuno competent
intestinal tract
crypto infects what in immunocompromised peeps
Pancreas, liver, respiratory tract, gall and urinary bladders
crypto: Inhibition of glucose-stimulation affecting,,,
Na absorbtion
crypto: Increase production of mucosal prostaglandin which can inhibit…
NaCl absorption leading to secretory diarrhea.
leukocytes can produce high levels of… in crypto
prostaglandins
crypto: Alterations in intestinal permeability due to the
-immune response to the parasite
-i.e.: Increased secretions of
cytokines like IFN-g and transforming growth factor (TGF)
what plays an important role in crypto pathogenesis
In patients having large volume of diarrhea (70 bowels movement per day) secretory processes of the parasites or
immune cells
what causes diarrhea
- Absorption is impaired
– Electroneutral (NaCl)
– Electrogenic (co-transport) - Secretion is enhanced
– Active Cl- or HCO3 - (bicarbonate)
- Causes:
– Toxins
– Pathogen adherence/invasion
– Stimulate immune response
How do Cryptosporidium cause diarrhea?
-inflammation
Increase in intracellular permeability
Inflammation in sub-mucosal layer
-Profuse watery diarrhea
Diarrhea is osmotic
Damage to epithelial cells:
villus blunting and atrophy
Hyperplasia
Crypto resides at….
-the apical surface of intestinal epithelial cells and does
not invade deeper layers of the human gastrointestinal mucosa
moderate to severe infections of crypto stimulate
both innate and acquired immunity
true or false: in crypto,
mucosal inflammation with the presence of macrophages and neutrophils at the site of infection
true
what are the key players for immune response to crypto
Key players: Epithelial cells, IFN-g, Phagocytes
Players with less-defined roles: Complement, DCs
in crypto: cells express the pro inflammatory … which is also a neutrophil attractant
il-8
in crypto infection: prostaglin is produced by what
produced by epithelial cells may serve to influence their
biological function
in crypto. nictric oxyde is produced by what
produced from arginine by the enzyme nitric oxide synthase (NOS).
in crypto: In the mouse model, B-cell-deficient neonatal mice can…..
clear the infection, indicating that the role of antibodies plays a minor role in the control of the infection.
true or false in crypto: Patients develop both serum and secretory antibodies, but
these specific antibodies are not successful in eliminating
the infection
true
true or false: in crypto humoral immunity is required for clearing the infection
false, it is not an absolute requirement
-it plays secondary role in combination with host factors
in crypto: The clearance of the infection in humans correlates with….
the CD4 T-cell population, not the CD8 T-cell.
The relationship existing between the CD4 T-cell population and Crypto explains why…
AIDS patients are seriously affected by Cryptosporidium infection.
in crypto, strong early response and late th2 might what
help clearing
diagnostic tools crypto
- Microscopy
– Acid fast stain
– Fluorescent - Endoscopic biopsy
- Immunodiagnosis
– Immunofluorescence assay *
– Enzyme linked immunoabsorbant assay (ELISA) * - PCR-bassed assays
– RT-PCR quantify oocysts in stool
– PCR – standard and multiplex
– Loop-mediated isothermal DNA amplification (colorimetric)
– Oligometric gold nanoparticle networks
crypto: which diagnostic tools are not confirmative of active lesions
– Immunofluorescence assay *
– Enzyme linked immunoabsorbant assay (ELISA) *
treatment crypto
- Self-limiting infection
- Unless immunosuppressed
– Treatments are most important
– Chronic diarrhea can lead to malabsorption of
antiretroviral drugs in HIV patients
-anti-mobility agents: imodium
-rehydratation therapy: glutamine based better than glucose
-drygs
drug of choice for crypto for immunocompetent peeps
-Nitazoxanide (immunocompetent
people > 1year)
-–inhibits pyruvate:
ferredoxin/flavodoxin
oxidoreductases (PFOR) requiredfor anaerobic respiration
-important for parasites without mitochondria
Treatment of HIV-infected patients
- Outcome is inversely related to CD4+ T-cell count
- Paromomycin
-rifamycin
what is paromymicin
– aminoglycoside (inhibits protein synthesis)
– Partial efficacy in AIDs patients
* may relieve some diarrhea
* allows absorption of anti-retrovial drugswhat is
what is rifamycin
Blocks DNA-dependent RNA synthesis
– Least active
– Can be used for:
* prophylaxis
* In combination with other antiparasitic drugs
novel therapy for c parvum
PROTEASE INHIBITOR K11777
-Enzymes catalyzes the hydrolysis of peptide bonds
-[ Proteases has been shown to be a critical importance in development
and host cell invasion for other apicomplexan parasites
-momar worked on it
