Parasitic Protozoans Lab

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Parasitic ProtozoansLab 14Fall 2009

• Introductory Survey

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Giardia What is giardiasis?

• Giardiasis (GEE-are-DYE-uh-sis) is a diarrheal
  illness caused by a one-celled, microscopic
  parasite, Giardia intestinalis (also known as
  Giardia lamblia).
• Once an animal or person has been infected with
  Giardia intestinalis, the parasite lives in the
  intestine and is passed in the stool.
• The parasite is protected by an outer shell, it
  can survive outside the body and in the
  environment for long periods of time.
• Diagnosis is confirmed by fecal smear
• http//www.cdc.gov/Ncidod/dpd/parasites/giardiasis
  /factsht_giardia.htmwhat

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Entamoeba histolyticaAmoebic dysentery

• Amoebiasis
• Demonstration of cysts or trophozoites of E.
  histolytica in stool or
• single celled parasitic animal, i.e., a protozoa,
  that infects predominantly humans and other
  primates
• The active (trophozoite) stage exists only in the
  host and in fresh feces cysts survive outside
  the host in water and soils and on foods,
  especially under moist conditions on the latter.
  When swallowed they cause infections by excysting
  (to the trophozoite stage) in the digestive
  tract.
• Diagnosis of cysts or trophozoites in fecal smear

• VIDEO

• http//www.cdc.gov/epo/dphsi/casedef/amebiasis_cur
  rent.htm

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Balantidium coliBalantidiasis

• species of ciliate protozoan, and is the only one
  that is pathogenic in humans
• intestinal protozoan parasite
• Cysts are the parasite stage responsible for
  transmission of balantidiasis.
• excystation occurs in the small intestine, and
  the trophozoites colonize the large intestine.
• Sausage shaped macronucleus
• Diagnosis made by fecal smear
• VIDEO

LM
cyst
trophozoite
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TrichomonasTrichimoniasis

• anaerobic, parasitic flagellated protozoan
• Five flagella arise near the cytosome
• Does not have a cyst form
• organisms can survive for up to 24 hours in
  urine, semen, or even water samples
• one of the most common sexually transmitted
  disease. In North America, it is estimated that
  more than 8 million new cases are reported
  yearly.
• Diagnosis is confirmed by vaginal smear VIDEO

http//www.cdc.gov/STD/Trichomonas/STDFact-Trichom
oniasis.htmWhatIs
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TrypanosomaSleeping Sickness

• Parasitic protozoan of the phylum Euglenozoa
• African sleeping sickness
• transmitted by biting insects such as the tsetse
  fly
• Complex life cycle
• parasites enter the human host through mucus
  membranes in the nose, eye, or mouth upon release
  from the insect vectors.
• Left untreated, Chagas' disease, (T. cruzi,)
  may cause dementia, megacolon, and megaesophagus,
  and damage to the heart muscle, and may result in
  death.
• Diagnosis is parasite present in blood among
  RBCs.

www.cdc.gov
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PlasmodiumMalaria

• Plasmodium life cycle which is split between a
  vertebrate host and an insect vector (Anopheles
  mosquito)
• Morphology -Malarial parasite trophozoites are
  can be ring shaped, 1-2 microns in size, although
  other forms (ameboid and band) may also exist.
• The sexual forms of the parasite (gametocytes)
  are much larger and 7-14 microns in size.
• P. falciparum is the largest and deadliest and
  banana shaped.
• Diagnosis is confirmed by blood smear.

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Naeglaria fowleri

• Primary amebic meningoencephalitis (PAM) is
  invariably an acute, often fulminant infection
• a small, free-living ameba that occasionally
  infects humans and other mammals.
• rare (200 cases have been reported worldwide to
  date), PAM is frequently difficult to diagnose,
  and does not have effective therapeutic options
• Found in warm bodies of fresh water, such as
  lakes, rivers, and hot springs warm water
  discharge from industrial plants,
  Under-chlorinated swimming pools
• 100 fatality