Other Human Amoebae

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Other Human Amoebae

• Entamoeba dispar/E. hartmanni Non pathogenic
  anatomically indistinguishable from E.
  histolytica.

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Entamoeba coli
Trophozoite Cyst
Nucleus
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Entamoeba coli

• Life cycle and location identical to E.
  histolytica.

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Entamoeba coli

• Life cycle and location identical to E.
  histolytica.
• Most common endocommensal in people has a
  worldwide distribution and 10-50 of the
  population can be infected in different parts of
  the world.

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Entamoeba coli

• Life cycle and location identical to E.
  histolytica.
• Most common endocommensal in people has a
  worldwide distribution and 10-50 of the
  population can be infected in different parts of
  the world.
• Not pathogenic.

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Entamoeba coli

• Life cycle and location identical to E.
  histolytica.
• Most common endocommensal in people has a
  worldwide distribution and 10-50 of the
  population can be infected in different parts of
  the world.
• Not pathogenic.
• Feeds on bacteria and any other cells available
  to it does not invade
  tissue.

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Other Hosts
Monkeys
Apes
Pigs
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10 mm
Trophozoites 20-30 µm in diameter (15-50 µm)
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A
B
D
C
10 mm
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E. coli E. histolytica
A
B
D
C
10 mm
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C
Cysts 10-30 µm
10 mm
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Entamoeba gingivalis
  Habitat Mouth Hosts Humans, other primates,
dogs and cats.
Prevalence is from 50 to 95.   Stage
Trophozoite, no cyst.  
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Entamoeba gingivalis
  Trophozoite lives on the surface of teeth and
gums. Feed on epithelial cells of the mouth,
bacteria, food debris, and other cells available
to them.  
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Entamoeba gingivalis
  Trophozoite lives on the surface of teeth and
gums. Feed on epithelial cells of the mouth,
bacteria, food debris, and other cells available
to them. Organisms are more common in persons
with pyorrhea (gum disease) but they are not the
cause of the condition.
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Entamoeba gingivalis
  Trophozoite lives on the surface of teeth and
gums. Feed on epithelial cells of the mouth,
bacteria, food debris, and other cells available
to them. Organisms are more common in persons
with pyorrhea (gum disease) but they are not the
cause of the condition. Transmission
mouth to mouth, droplet spray, or sharing eating
utensils.  
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Endolimax nana The dwarf internal slug
Trophozoite Cyst
Nucleus
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Endolimax nana

• Second most common endocommensal of humans,
  worldwide distribution 30.

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Endolimax nana

• Second most common endocommensal of humans,
  worldwide distribution 30.
• Lives in the large intestine mainly near the
  cecum and feed on bacteria non pathogenic.

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Endolimax nana

• Second most common endocommensal of humans,
  worldwide distribution 30.
• Lives in the large intestine mainly near the
  cecum and feed on bacteria non pathogenic.
• Also occurs in monkeys.

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Trophozoites are tiny 6-15 µm in diameter. Large
glycogen vacuoles are often present.
10 mm
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Mature cyst is 5 14 µm in diameter contains 4
nuclei shape is round to elliptical
10 mm
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Iodamoeba buetschlii
Trophozoite Cyst
Nucleus
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Iodamoeba buetschlii

• Not very common endocommensal in people.

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Iodamoeba buetschlii

• Not very common endocommensal in people.
• Lives in the large intestine, predominantly in
  the cecal areas.

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Iodamoeba buetschlii

• Not very common endocommensal in people.
• Lives in the large intestine, predominantly in
  the cecal areas.
• Has a very high prevalence in pigs 50 of pigs
  are infected with this ameba in France and Egypt
  pigs are probably its normal host.

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Trophozoites are 9-14 µm long but may be as large
as 20µm
10 mm
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10 mm
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E. nana
10 mm
I. buetschlii
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Cysts are 6-15 µm long and have a large glycogen
vacuole.
10 mm
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Dientamoeba fragilis
Trophozoite No Cyst
Nucleus
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Dientamoeba fragilis

• LIFE CYCLE - it does not form cysts and
  trophozoites cannot survive passage through the
  small intestine.

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Dientamoeba fragilis

• LIFE CYCLE - it does not form cysts and
  trophozoites cannot survive passage through the
  small intestine.
• Humans probably get infected by this
  endocommensal when they ingest pinworm eggs!

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Trophozoites small 6-12 µm long binucleated.
10 mm
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Histomonas meleagridis

• Cosmopolitan parasite of Birds in the order
  Galiformes.
• Causes a severe and often fatal disease called
  histomoniasis, blackhead in turkeys.
• Only a trophozoite stage present no cyst
• trophozoite is irregular in shape
• may appear as an amoeboid form with pseudopodia
  or a flagellated form with a single flagellum
•  

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Histomonas meleagridis Life Cycle
Transmission is within the egg of the cecal
nematode of chickens and turkeys (Heterakis
gallinarum)
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Histomonas meleagridis Life Cycle
Transmission is within the egg of the cecal
nematode of chickens and turkeys (Heterakis
gallinarum) - trophozoites from the cecum of an
infected bird are ingested by the nematode and
invade the eggs
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Histomonas meleagridis Life Cycle

• Transmission is within the egg of the cecal
  nematode of chickens and turkeys (Heterakis
  gallinarum)
• trophozoites from the cecum of an infected bird
  are ingested by the nematode and invade the eggs
• - infected eggs of the nematode are released onto
  the soil where they are eaten by young birds
  during pecking activities

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Histomonas meleagridis Life Cycle
Transmission is within the egg of the cecal
nematode of chickens and turkeys (Heterakis
gallinarum) - trophozoites from the cecum of an
infected bird are ingested by the nematode and
invade the eggs - infected eggs of the nematode
are released onto the soil where they are eaten
by young birds during pecking activities - as
nematode eggs hatch in the small intestine,
Histomonas trophozoites are released to invade
the cecum.
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this parasite
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Pinpoint ulcers
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Histomonas meleagridis pathology
Habitat of trophozoites Cecum Pathology
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Histomonas meleagridis pathology
Habitat of trophozoites Cecum Pathology Young
turkeys are more susceptible to the infection
than are chickens. Mortality can reach 100 in
young turkeys - millions of dollars worth of
turkeys are lost to this parasite.
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Symptoms

• Infected birds develop ruffled feathers, dark
  skin pigmentation, and hanging wings and tail

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Look at Mr. Pro Diver!!!
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Hello, The VISIBVILITY IS GREAT!!!!
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Steering Wheel
Matts hose and his bubbles
This is Matt!! Holding a steering wheel of a
sunken boat!! Melissa took the picture from too
far away. Sorry Matt
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Amoebic Meningitis
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Naegleria fowleri

• Free-living in freshwater and soil including
  thermal pools are bacteriophagous.
• They have even been isolated from bottled mineral
  water in Mexico.

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Naegleria fowleri Life Cycle
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Naegleria fowleri Pathology

• After entering the nose and nasal cavities, the
  trophozoites migrate along the olfactory nerves,
  through the cribriform plate, and into the
  cranium.

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Naegleria fowleri Pathology

• After entering the nose and nasal cavities, the
  trophozoites migrate along the olfactory nerves,
  through the cribriform plate, and into the
  cranium.
• Ameboid trophozoites multiply rapidly by binary
  fission in the brain and cause rapid brain tissue
  destruction.

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Naegleria fowleri Pathology

• After entering the nose and nasal cavities, the
  trophozoites migrate along the olfactory nerves,
  through the cribriform plate, and into the
  cranium.
• Ameboid trophozoites multiply rapidly by binary
  fission in the brain and cause rapid brain tissue
  destruction.
• Symptoms include a headache, fever, neck
  rigidity, and mental confusion followed by coma
  and death.

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Naegleria fowleri Pathology

• After entering the nose and nasal cavities, the
  trophozoites migrate along the olfactory nerves,
  through the cribriform plate, and into the
  cranium.
• Ameboid trophozoites multiply rapidly by binary
  fission in the brain and cause rapid brain tissue
  destruction.
• Symptoms include a headache, fever, neck
  rigidity, and mental confusion followed by coma
  and death.
• Death usually occurs from brain destruction.

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Trophozoites are clustered around small vessels
near the brain surface
Primary Amebic Meningoencephalits (PAM)
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Figure 1. A) Computed tomographic scan note the
right fronto-basal collection (arrow) with a
midline shift right to left. B) Brain histology
three large clusters of amebic vegetative forms
are seen (H-E stain, x 250). Inset Positive
indirect immunofluorescent analysis on tissue
section with anti Naegleria fowleri serum.
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Naegleria in Oklahoma

• Two boys, ages 7 and 9, in Tulsa, Oklahoma, died
  from rare parasite Saturday August 5, 2005 from
  infection with Naegleria fowleri.

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Naegleria in Oklahoma

• Two boys, ages 7 and 9, in Tulsa, Oklahoma, die
  from rare parasite Saturday August 5, 2005 from
  infection with Naegleria fowleri.
• The two boys were not related, but both came to
  their doctors with symptoms of fever,
  hallucinations, and headaches, and despite
  medical care neither was able to survive the
  deadly infection.

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Naegleria in Oklahoma

• Two boys, ages 7 and 9, in Tulsa, Oklahoma, die
  from rare parasite Saturday August 5, 2005 from
  infection with Naegleria fowleri.
• The two boys were not related, but both came to
  their doctors with symptoms of fever,
  hallucinations, and headaches, and despite
  medical care neither was able to survive the
  deadly infection.
• Of the 200 known cases of Naegleria infection in
  the past 40 years, only two people have survived.
  Only 24 infections were documented in the U.S.
  between 1989 and 2000.

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Acanthamoeba spp.
At least 5 species of Acanthamoeba have been
identified in human tissues, this is one of the
most common amebas in soil and freshwater. Tropho
zoites occur only as amoeboid forms
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Life Cycle Stages
Free-living trophozoites and cysts occur in both
the soil and freshwater.
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Acanthamoeba spp.
These species cause 2 pathological effects
1) Over 100 cases of granulomatous amebic
meningoencephalitis caused by Acanthamoeba have
been documented.
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2) Incriminated in a number of cases of
inflammation and opacity of the cornea.
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Most of these ocular infections were in contact
lens wearers who used home-made saline.
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Symptoms

• Foreign body sensation, severe ocular pain,
  photophobia and blurred vision.
• Often pain is more severe than signs in early
  course of the disease.

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Pathology

• Usually unilateral diffuse punctate
  epitheliopathy, dendritic epithelial lesion which
  may gradually progress to stromal infection
  associated with ring infiltrate formation.

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Pathology

• Usually unilateral diffuse punctate
  epitheliopathy, dendritic epithelial lesion which
  may gradually progress to stromal infection
  associated with ring infiltrate formation.
• Enlarged corneal nerve (keratoneuritis) is
  pathognomonic of the infection.

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Pathology

• Usually unilateral diffuse punctate
  epitheliopathy, dendritic epithelial lesion which
  may gradually progress to stromal infection
  associated with ring infiltrate formation.
• Enlarged corneal nerve (keratoneuritis) is
  pathognomonic of the infection.
• Scleritis may be found in advanced cases.

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Acanthamoeba spp.

• Management
• Early diagnosis a prognostic factor of a
  successful outcome.
• Topical anti-amoeba agents.
• Penetrating keratoplasty in a severe progressive
  keratitis.