amebiasis is caused by what

Question 1

amebiasis is caused by what

Answer 1

entamoeba hystolicica

Question 2

Brumpt 1949, proposed to establish a new species of ….. to designate the
amoebae that are not pathogenic

Answer 2

Entamoeba

Question 3

In 1993, it was decided that the invasive form will be called …..

Answer 3

E. histolytica.

Question 4

The non-invasive form of entamoeba will be called

Answer 4

E dispar

Question 5

true or false, we can distinguish both entamoeba under the microscopy

Answer 5

false

Question 6

what are the non pathogenic entamoeba

Answer 6

Entamoeba hartmani
Entamoeba dispar
Entamoeba coli

Question 7

what is the three most common parasitic cause of death

Answer 7

entamoaba hystolitica
-70-100 000 per year

Question 8

how many people are infected with entamoeba hysto

Answer 8

500 million

Question 9

true or false: entamoeba hysto is waterborne

Answer 9

true
§ Water, food
§ Flies can act as passive vectors
§ Can be sexually transmitted
§ Person-to-person contacts

Question 10

where is entamoeba found

Answer 10

Mexico, Central & South America, Africa, South Asia

Question 11

true or false: humans are the only source for entamoeba

Answer 11

true

Question 12

what is the transmission for entamoeba

Answer 12

fecal and oral

Question 13

what are the 4 things about amebiasis

Answer 13

1) asymptomatic carrier state
2) acute amoebic dysentery
3) amoebic liver abscess
4) amoeboma

Question 14

presence in the world E. histolytica/dispar

Answer 14

developing countries is ~10% E. histolytica;
developed countries is ~1% E. histolytica

Question 15

the infective dose of entamoeba can be as little as

Answer 15

1 cyst

Question 16

what is the incubation period entamoe

Answer 16

few days to few weeks depending on dpse

Question 17

true or false: entamoeba cysts can survive for weeks at appropriate temperatire and humudity

Answer 17

true

Question 18

cytoplasmic structures entamoeba

Answer 18

-nucleus: the inner surface membrane is line with periferal chronation, you get like 1-4 lil rings
-endosome: located in the center of the nucleus and they contain dna
-vacuoles: They occupy a great proportion of the
cytoplasm. They vary between 5 to 9µ
in size.

Question 19

what are vacuoles important for in entamoeba

Answer 19

They may contain cellular debris, red blood
cells, bacteria - feeding

Question 20

Amoeba cells can live and multiply indefinitely within the
crypts of the mucosa of the…..

Answer 20

large intestine

Question 21

true or false: entamoeba are able to invade the mucus later

Answer 21

true
it constitutes a major non specific defense mechanism

Question 22

what do entamoeba feed on

Answer 22

They feed on starches and mucous secretions and interacting metabolically
with enteric bacteria.

Question 23

entamoeba initiate tissue invasion when they……

Answer 23

-they hydrolyse mucosal cells and absorb the
pre-digested products.
-At this stage they no longer need to feed on bacteria.

Question 24

Tiny cytoplasmic extensions from the surface of trophozoites called …

Answer 24

filopodia

Question 25

Tiny cytoplasmic extensions from the surface of trophozoites called filopodia may have the following functions related to
pathogenesis:

Answer 25

• Endocytosis
• Attachment to substrate
• Penetration of tissue
• Release of cytotoxic materials
• Cytolysis of cells

Question 26

presentation of entamoeba

Answer 26

• Diarrhea to dysentery with bloody and mucous
• Fever
• Abdominal pain

Question 27

diagnosis entamoeba

Answer 27

• Amoebic (hematophagous trophozoites and cysts) in stool
• Patchy inflammation seen on colonoscopy
• Serology – antibodies in serum
• Stool PCR - detection of parasite DNA in stool
• Antigen capture – detection of parasite protein in stool

Question 28

pathology entamoeba: intestine

Answer 28

-Remarkable and unique ability to hydrolyze host tissues with their active proteases present on the surface membrane of the trophozoite.
-Lesions are found in the caecum, appendix, or colon. They may heal.
-If perforation of the colon occurs, there is peritonitis that can lead to death.

Question 29

Amoeboma - Granuloma obstructing the …

Answer 29

bowel

Question 30

Hepatic amebiasis occurs
when trophozoites enter t…

Answer 30

mesenteric veinule and travel
to the liver through the
hepatic portal system.

Question 31

Only about 5-10% of
infections will affect …. for entamoeba

Answer 31

the liver.

Question 32

treatment entamoeba:

Answer 32

Metronidazole or tinidazole, followed by iodoquinol or paromomycin

Question 33

mechanism of cytotoxicity entamoeba

Answer 33

1. Direct contacts with the host tissues
2. Release of soluble toxic metabolites
3. High enzymatic activities of the amoebas
4. Interfering with the immune response of the host.

Question 34

entamoeba: Direct contacts with the host tissues.

Answer 34

adherence to the host cell by the release of adhesin
molecules.

Question 35

entamoeba: Release of soluble toxic metabolites.

Answer 35

amoebapore are capable of forming a hole in a target cell.

Question 36

The immune system can kill the amoebic cell: how

Answer 36

-macrophages
-cytotoxic cd8t cells
-antibodies don’t do much

Question 37

Macrophages activated by cytokines can kill Entamoeba trophozoites. The killing mechanism is contact-dependent and is mediated by both…..

Answer 37

oxygen and oxygen independant mechanisms

Question 38

True or false: Antibody-dependent cell-mediated-cytotoxicity is not an active mechanism to kill entamoeba.

Answer 38

true

Question 39

Lysis of amoebas has not been observed with either immune serum alone or with complement. Therefore, …

Answer 39

Th2 type of immune response is not playing a major role against amoebiasis

Question 40

amebiasis of the skin

Answer 40

• This infection arises by direct spread of a primary abscess.
• This patient was erroneously
  operated for a perforated duodenal
  ulcer and no anti-amoebic drugs were
  given.