Amoeba Flashcards
List of Amoeba
Entamoeba histolytica, Entamoeba hartmannii, Entamoeba coli, Endolimax nana, and Iodamoeba butschlii
List of Amoeboflagellates
Acanthamoeba and Naegleria fowleri
List of Flagellates
Giardia spp., Dientamoeba fragillis, Chilomastrix mesnili, and Trichomonas spp.
List of Hemoflagellates
Leishmania spp. and Trypanosoma spp.
What is the pathogenic ciliate?
The only ciliate that is pathogenic to humans is Balantidium coli
List of Coccidia
Cryptosporidium parvum, Cyclospora cayetanesis, Cystioisospora belli, Blastocystic hominis, and Microsporidia spp.
Which stain should be used for Trophozoites?
It can be unstained with saline or formalin or stained with neutral red or a permanent stain
Which stain should be used for cysts?
It can be unstained with saline or formalin or stained with iodine or a permanent stain
Entamoeba histolytica trophozoites characteristics
10-60 um, 1 nucleus (not visible in unstained preps), usually a small centrally located karyosome
Entamoeba hartmanni trophozoites characteristics
5-12 um, 1 nucleus (no visible in unstained preps), usually has a small eccentric karyosome
Entamoeba coli trophozoites characteristics
15-50 um, 1 nucleus (often visible without a stain), large eccentric karyosome
Endolimax nana trophozoites characteristics
6-12 um, 1 nucleus that is visible sometimes unstained, no peripheral chromatin and a large irregularly shaped karyosome
Iodamoeba buetschlii trophozoites characteristics
8-20 um, 1 nucleus not visible unstained, no peripheral chromatin, and a large centrally located karyosome that is surrounded by refractile granules
Dientamoeba fragilis trophozoite characteristics
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
Entamoeba histolytica cyst characteristics
10-20 um, 4 nuclei in mature cysts
Entamoeba hartmanni cyst characteristics
5-10 um, 4 nuclei in mature cysts
Entamoeba coli cyst characteristics
10-35 um, 8 nuclei in mature cysts (there are sometimes super-nucleated cysts with 16+ nuclei)
Endolimax nana cyst characteristics
5-10 um, 4 nuclei in mature cysts
Iodamoeba buetschlii cyst characteristics
5-20 um, 1 nucleus
Pentatrichomonas hominis trophozoite characteristics
6-20 um, pear shaped with 1 nucleus, 3-5 anterior flagella and 1 posterior
Chilomastix mesnili trophozoite characteristics
6-24 um, pear shaped with 1 nucleus, 3 anterior flagella and 1 in the cytosome
Giardia duodenalis trophozoite characteristics
10-20 um, pear shaped with 2 nuclei, and 4 lateral, 2 ventral, and 2 caudal flagella
Enteromonas hominis trophozoite characteristics
4-10 um, oval shaped with 1 nucleus, and 3 anterior and 1 posterior flagella
Retortamonas intestinalis trophozoite characteristics
4-9 um, pear shaped with 1 nucleus, and 1 anterior and 1 posterior flagella
Pentratrichomonas hominis cyst characteristics
This organism does not have a cyst form
Chilomastix mesnili cyst characteristics
6-10 um, lemon shaped with anterior hyaline knob, 1 nucleus
Giardia duodenalis cyst characteristics
8-19 um, oval shaped with 5 nuclei
Enteromonas hominis cyst characteristics
4-10 um, with 1-4 nuclei but usually 2 lying at opposite ends
Retortamonas intestinalis cyst characteristics
4-9 um, pear shaped with 1 nucleus
Balantidium coli characteristics
Trophozoite: 50-70 um, 1 large kidney shaped macronucleus and 1 small micronucleus adjacent to it
Cyst: 45-65 um, 1 large macronucleus
Cystoisospora belli characteristics
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
Sarcocystis hominis
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
Sarcocystic suhominis characteristics
sporocyst: 1-15 um, non motile, same as other species
Cryptosporidium characteristics
Oocyst: 3-6 um, non motile, mature oocyst contains 4 naked sporozoites and there are no sporocysts seen
Blastocystic hominis
Vacuolated form: 5-30 um, non motile, usually 1 nucleus but can have 2-4, cells contain a large vacuole
Naegleria fowler clinical disease
Causes severe CNS dysfunction with rapid degeneration caused by hemorrhagic-necrotizing meningoencephalitis (causes amebic meningoencephalitis)
Naegleria folwer characteristics
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
Acathamoeba spp. clinical disease
Causes granulamatous amebic encephalitis; contact lens use is the most important risk factor for the developed world
Acanthamoeba spp. characteristics
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
Balamuthia mandrillaris characteristics
Cannot be distinguished from Acanthamoeba without molecular testing
Trichomonas vaginalis characteristics
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
Toxoplasma gondii characteristics
Trophozoites: 4-8 um, with a tapered anterior end and blunt posterior end
Oocysts are the infective stage
Leishmania spp. clinical disease
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)
Leishmania spp. characteristics
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
Trypanosoma brucei clinical disease
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
Trypanosoma brucei characteristics
The infective form passed from the tsetse fly to humans is the metacyclic trypomastigotes. 14-33 um
Trypanosoma cruzi clinical disease
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
Trypanosoma cruzi characteristics
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
