Amoeba

Question 1

List of Amoeba

Answer 1

Entamoeba histolytica, Entamoeba hartmannii, Entamoeba coli, Endolimax nana, and Iodamoeba butschlii

Question 2

List of Amoeboflagellates

Answer 2

Acanthamoeba and Naegleria fowleri

Question 3

List of Flagellates

Answer 3

Giardia spp., Dientamoeba fragillis, Chilomastrix mesnili, and Trichomonas spp.

Question 4

List of Hemoflagellates

Answer 4

Leishmania spp. and Trypanosoma spp.

Question 5

What is the pathogenic ciliate?

Answer 5

The only ciliate that is pathogenic to humans is Balantidium coli

Question 6

List of Coccidia

Answer 6

Cryptosporidium parvum, Cyclospora cayetanesis, Cystioisospora belli, Blastocystic hominis, and Microsporidia spp.

Question 7

Which stain should be used for Trophozoites?

Answer 7

It can be unstained with saline or formalin or stained with neutral red or a permanent stain

Question 8

Which stain should be used for cysts?

Answer 8

It can be unstained with saline or formalin or stained with iodine or a permanent stain

Question 9

Entamoeba histolytica trophozoites characteristics

Answer 9

10-60 um, 1 nucleus (not visible in unstained preps), usually a small centrally located karyosome

Question 10

Entamoeba hartmanni trophozoites characteristics

Answer 10

5-12 um, 1 nucleus (no visible in unstained preps), usually has a small eccentric karyosome

Question 11

Entamoeba coli trophozoites characteristics

Answer 11

15-50 um, 1 nucleus (often visible without a stain), large eccentric karyosome

Question 12

Endolimax nana trophozoites characteristics

Answer 12

6-12 um, 1 nucleus that is visible sometimes unstained, no peripheral chromatin and a large irregularly shaped karyosome

Question 13

Iodamoeba buetschlii trophozoites characteristics

Answer 13

8-20 um, 1 nucleus not visible unstained, no peripheral chromatin, and a large centrally located karyosome that is surrounded by refractile granules

Question 14

Dientamoeba fragilis trophozoite characteristics

Answer 14

5-15 um, 2 nuclei (sometimes only 1) cannot be seen unstained, no peripheral chromatin, and a large cluster of 4-8 granules for the karyosome

Question 15

Entamoeba histolytica cyst characteristics

Answer 15

10-20 um, 4 nuclei in mature cysts

Question 16

Entamoeba hartmanni cyst characteristics

Answer 16

5-10 um, 4 nuclei in mature cysts

Question 17

Entamoeba coli cyst characteristics

Answer 17

10-35 um, 8 nuclei in mature cysts (there are sometimes super-nucleated cysts with 16+ nuclei)

Question 18

Endolimax nana cyst characteristics

Answer 18

5-10 um, 4 nuclei in mature cysts

Question 19

Iodamoeba buetschlii cyst characteristics

Answer 19

5-20 um, 1 nucleus

Question 20

Pentatrichomonas hominis trophozoite characteristics

Answer 20

6-20 um, pear shaped with 1 nucleus, 3-5 anterior flagella and 1 posterior

Question 21

Chilomastix mesnili trophozoite characteristics

Answer 21

6-24 um, pear shaped with 1 nucleus, 3 anterior flagella and 1 in the cytosome

Question 22

Giardia duodenalis trophozoite characteristics

Answer 22

10-20 um, pear shaped with 2 nuclei, and 4 lateral, 2 ventral, and 2 caudal flagella

Question 23

Enteromonas hominis trophozoite characteristics

Answer 23

4-10 um, oval shaped with 1 nucleus, and 3 anterior and 1 posterior flagella

Question 24

Retortamonas intestinalis trophozoite characteristics

Answer 24

4-9 um, pear shaped with 1 nucleus, and 1 anterior and 1 posterior flagella

Question 25

Pentratrichomonas hominis cyst characteristics

Answer 25

This organism does not have a cyst form

Question 26

Chilomastix mesnili cyst characteristics

Answer 26

6-10 um, lemon shaped with anterior hyaline knob, 1 nucleus

Question 27

Giardia duodenalis cyst characteristics

Answer 27

8-19 um, oval shaped with 5 nuclei

Question 28

Enteromonas hominis cyst characteristics

Answer 28

4-10 um, with 1-4 nuclei but usually 2 lying at opposite ends

Question 29

Retortamonas intestinalis cyst characteristics

Answer 29

4-9 um, pear shaped with 1 nucleus

Question 30

Balantidium coli characteristics

Answer 30

Trophozoite: 50-70 um, 1 large kidney shaped macronucleus and 1 small micronucleus adjacent to it Cyst: 45-65 um, 1 large macronucleus

Question 31

Cystoisospora belli characteristics

Answer 31

Oocyst: 25-30 um, non motile, usually diagnosed when there is an immature oocyst with a single granular mass (zygote) within it. Mature oocyst has 2 sporocysts with 4 sporozoites each

Question 32

Sarcocystis hominis

Answer 32

sporocyst: 13-17 um, non motile, mature oocysts have a thin wall collapsed around 2 sporocysts or free fully mature sporocysts with 4 sporozoites inside are seen in stool

Question 33

Sarcocystic suhominis characteristics

Answer 33

sporocyst: 1-15 um, non motile, same as other species

Question 34

Cryptosporidium characteristics

Answer 34

Oocyst: 3-6 um, non motile, mature oocyst contains 4 naked sporozoites and there are no sporocysts seen

Question 35

Blastocystic hominis

Answer 35

Vacuolated form: 5-30 um, non motile, usually 1 nucleus but can have 2-4, cells contain a large vacuole

Question 36

Naegleria fowler clinical disease

Answer 36

Causes severe CNS dysfunction with rapid degeneration caused by hemorrhagic-necrotizing meningoencephalitis (causes amebic meningoencephalitis)

Question 37

Naegleria folwer characteristics

Answer 37

Trophozoites (infective form): 7-35 um with a large central karyosome Cysts (not found in tissue): 7-15 um with a thick double wall Can have a flagellated stage

Question 38

Acathamoeba spp. clinical disease

Answer 38

Causes granulamatous amebic encephalitis; contact lens use is the most important risk factor for the developed world

Question 39

Acanthamoeba spp. characteristics

Answer 39

Trophozoites (infective form): 1 nucleus and a large central nucleolus and a large vacuole, and 15-45 um Cysts: 8-24 um, rounded with a double wall

Question 40

Balamuthia mandrillaris characteristics

Answer 40

Cannot be distinguished from Acanthamoeba without molecular testing

Question 41

Trichomonas vaginalis characteristics

Answer 41

Trophozoite: 7-30 um, 4 anterior flagella and 1 posterior with a large nucleus. Does not have a cyst form and does not survive well in the environment. Passed as an STD

Question 42

Toxoplasma gondii characteristics

Answer 42

Trophozoites: 4-8 um, with a tapered anterior end and blunt posterior end Oocysts are the infective stage

Question 43

Leishmania spp. clinical disease

Answer 43

causes leishmaniasis: vector-borne disease transmitted by sandflies. There are two main forms of disease - cutaneous (lesions/sores) or visceral (fever, weight loss, swollen glands, and an enlarged spleen and liver)

Question 44

Leishmania spp. characteristics

Answer 44

Amastigotes: 1-5 um with a large nucleus and resides in macrophages of the host throughout the body The infective stage that is transmitted from the sandfly to human is the promastigotes which will become amastigotes

Question 45

Trypanosoma brucei clinical disease

Answer 45

Referred to as African trypanosomes/Sleeping sickness. The first stage of disease is characterized by nonspecific signs like fever and lymphadenopathy. The second stage occurs with the invasion of the CNS leading to neuropsychiatric manifestations like sleep disorders

Question 46

Trypanosoma brucei characteristics

Answer 46

The infective form passed from the tsetse fly to humans is the metacyclic trypomastigotes. 14-33 um

Question 47

Trypanosoma cruzi clinical disease

Answer 47

causes Chagas disease (American trypanosomiasis). There is an acute and chronic phase where the acute phase is generally asymptomatic or nonspecific somatic symptoms. Nodule lesions (chagomas) can develop around the feeding site

Question 48

Trypanosoma cruzi characteristics

Answer 48

The infected triatomine insect releases trypomastigotes in its feces near the bite wound and it enters the skin. They are only found in blood of an infected person, 12-30 um