Amoeba Flashcards
(155 cards)
1
Q
What are protozoa?
A
Unicellular organisms and independent. The lowest form of animal life. Pathogenic and non-pathogenic.
2
Q
What does the word ‘amoeba’ derive from?
A
The Greek word ‘amoibe’, which means change.
3
Q
What are the two forms of amoeba based on environmental factors?
A
Cysts and trophozoites.
4
Q
What type of locomotion organelle do amoebas possess?
A
Pseudopods.
5
Q
Which classifications according to habitat are there for amoebae?
A
- Intestinal amoebae
- Free-living amoebae
6
Q
What is the function of the nucleus in protozoa?
A
Contains chromosomes essential for life, reproduction, and genetic transmission.
7
Q
What is a karyosome?
A
An aggregate mass inside the nucleus.
8
Q
What are the two types of nuclei found in protozoa?
A
- Vesicular nucleus
- Compact nucleus
9
Q
What does the cytoplasm in protozoa contain?
A
Organelles.
10
Q
What are the two proportions of cytoplasm?
A
- Endoplasm
- Ectoplasm
11
Q
What is found in the endoplasm?
A
Mitochondria, Golgi, ER, microsomes, stored food.
12
Q
What is the function of ectoplasm?
A
Aids in locomotion, food acquisition, respiration, excretion, and protection.
13
Q
What are pseudopodia?
A
Temporary, finger-like projections in amoebas for movement and food acquisition.
14
Q
What type of locomotion organelle is found in zoomastigiphora?
A
Flagella.
15
Q
What is the axoneme?
A
The internal portion attached to the kinetoplast in flagella.
16
Q
What are cilia?
A
Numerous short projections in ciliophora, arising from basal granules in the ectoplasm covering the parasite’s body.
17
Q
What is the feeding stage of amoebas called?
A
Trophozoite
Trophozoite is the active, vegetative stage where amoebas feed and grow.
18
Q
What type of reproduction occurs in the trophozoite stage?
A
Asexual
Trophozoites reproduce asexually, allowing for rapid population increase.
19
Q
What structure do trophozoites use for movement?
A
Pseudopods
Pseudopods are temporary projections that help amoebas move and capture food.
20
Q
What is the characteristic of the cyst stage of amoebas?
A
Non-feeding stage
Cysts are dormant and do not feed, preparing the organism for survival in harsh conditions.
21
Q
What type of reproduction occurs in the cyst stage?
A
Sexual
Cysts can undergo sexual reproduction, leading to genetic variation.
22
Q
What is the purpose of the thick cell wall in cysts?
A
Protective function
The thick cell wall protects the cyst from environmental stresses and allows for dormancy.
23
Q
What process transforms trophozoites into cysts?
A
Encystation
Encystation allows amoebas to survive unfavorable conditions by forming cysts.
24
Q
Name one trigger for encystation.
A
Food scarcity
Other triggers include accumulation of metabolic waste, significant pH changes, and loss of water.
25
What is protective encystation?
No morphological changes, primarily for survival
## Footnote
Example: B. coli undergoes protective encystation to withstand adverse conditions.
26
What is reproductive encystation?
Nucleus multiplies within the cyst
## Footnote
This leads to multiple daughter organisms upon excystation, as seen in E. histolytica.
27
What process describes the transition from cysts back to trophozoites?
Excystation
## Footnote
Excystation is crucial for the reactivation of the amoeba in a suitable environment.
28
Name a trigger for excystation.
Osmotic changes in the environment
## Footnote
Other triggers include enzymatic action on the inner cyst wall and favorable pH.
29
What are standard procedures for detecting amoebas?
Direct saline wet preparations, direct iodine wet preparations, permanent slides
## Footnote
These methods help visualize motile trophozoites and enhance protozoan cysts.
30
What is the invasive stage of amoebas?
Trophozoite
## Footnote
Trophozoites can invade host tissues and cause infections.
31
Fill in the blank: Cysts are in a _______ stage.
Dormant
## Footnote
Dormancy allows cysts to survive until conditions are favorable for excystation.
32
True or False: Trophozoites have a thick cell wall.
False
## Footnote
Trophozoites are delicate and do not have a thick protective cell wall like cysts.
33
What is the subphylum of Entamoeba histolytica?
Sarcodina
34
What are the diseases and conditions associated with Entamoeba histolytica?
* Intestinal amebiasis
* Amoebic colitis
* Amebic dysentery
* Extra-intestinal amebiasis
* Amebic liver abscess (ALA - Most common disease)
35
How is Entamoeba histolytica transmitted?
Ingestion of mature infective cyst
36
What is the habitat of Entamoeba histolytica?
Large intestine
37
What is unique about Entamoeba histolytica among amoebas?
The only pathogenic amoeba
38
What is the structure of the trophozoite of Entamoeba histolytica?
Finger-like appearance
39
How many nuclei can be found in the trophozoite of Entamoeba histolytica?
1
40
Describe the karyosome of the trophozoite of Entamoeba histolytica.
Small and central
41
What cystoplasmic inclusions are found in the trophozoite of Entamoeba histolytica?
Ingested red blood cells
42
How many nuclei can be found in the cyst of Entamoeba histolytica?
1-4
43
Describe the structure of the cyst of Entamoeba histolytica.
Chromatoidal body; Cigar shaped
44
What cystoplasmic inclusions are found in the cyst of Entamoeba histolytica?
Chromatoid bars
45
What are the two types of endocytosis exhibited by Entamoeba histolytica?
* Phagocytosis - solid
* Pinocytosis - dissolved material
46
What is the main difference in the life cycle of Entamoeba histolytica?
Each cyst produces 4 daughter organisms called “metacystic trophozoites”
47
What are the prevention and control measures for Entamoeba histolytica?
* Provision of adequate, clean, and safe drinking water
* Proper disposal of human wastes with the use of sanitary toilets
* Control of insects such as flies and cockroaches
* Prevent and educate farmers on the use of human excreta as “night soils”
* Regular screening of food-handlers
* Prompt treatment of infected individuals and public education
48
What is the scientific name of the organism discussed?
Entamoeba hartmanni
49
To which subphylum does Entamoeba hartmanni belong?
Sarcodina
50
What class is Entamoeba hartmanni categorized under?
Lobosea
51
Name one disease caused by Entamoeba hartmanni.
Intestinal amebiasis
## Footnote
Other diseases include amoebic colitis, amebic dysentery, and extra-intestinal amebiasis.
52
What is the mode of transmission for Entamoeba hartmanni?
Ingestion of mature infective cyst
53
In which habitat can Entamoeba hartmanni typically be found?
Large intestine
54
Is Entamoeba hartmanni a commensal or pathogenic organism?
Commensal amoeba
55
How many nuclei does the trophozoite of Entamoeba hartmanni have?
1
56
Describe the karyosome of the trophozoite in Entamoeba hartmanni.
Small and central
57
What may be present as cystoplasmic inclusions in the trophozoite of Entamoeba hartmanni?
Ingested bacteria may be present
58
How many nuclei can be found in the cyst of Entamoeba hartmanni?
1-4
59
What is the karyosome like in the cyst of Entamoeba hartmanni?
Small and central
60
List one type of cystoplasmic inclusion found in the cyst of Entamoeba hartmanni.
Chromatoid bars
## Footnote
Diffuse glycogen mass is present in young cysts.
61
What is the subphylum classification of Entamoeba coli?
Sarcodina
62
What class does Entamoeba coli belong to?
Lobosea
63
Name a disease caused by Entamoeba coli.
Intestinal amebiasis
## Footnote
Other diseases include amoebic colitis, amebic dysentery, and extra-intestinal amebiasis.
64
What is the mode of transmission for Entamoeba coli?
Ingestion of mature infective cyst
65
Where does Entamoeba coli primarily inhabit?
Large intestine
66
What type of amoeba is Entamoeba coli?
Commensal amoeba
67
How many nuclei does a trophozoite of Entamoeba coli have?
1
68
Describe the karyosome of Entamoeba coli's trophozoite.
Large, irregular shape, eccentric
69
What can often be seen in the cystoplasmic inclusions of a trophozoite?
Vacuoles containing bacteria
70
How many nuclei can be found in the cyst of Entamoeba coli?
1-4
71
What is the karyosome shape in the cyst of Entamoeba coli?
Large, irregular shape, eccentric
72
What are the cystoplasmic inclusions found in the cyst of Entamoeba coli?
Chromatoid bars; Diffuse glycogen mass present in young cysts
73
What is the scientific name of the organism discussed?
Entamoeba polecki
## Footnote
This organism is classified under the subphylum Sarcodina.
74
To which class does Entamoeba polecki belong?
Lobosea
## Footnote
This classification is based on its morphological characteristics.
75
What is the primary mode of transmission for Entamoeba polecki?
Ingestion of mature infective cyst
## Footnote
This mode of transmission is significant for understanding infection routes.
76
What type of habitat does Entamoeba polecki primarily occupy?
Large intestine
## Footnote
This habitat is crucial for its life cycle and development.
77
Is Entamoeba polecki considered a pathogen in humans?
Nonpathogen
## Footnote
Infections in humans are relatively rare.
78
What is the life cycle of Entamoeba polecki similar to?
Entamoeba histolytica
## Footnote
Understanding this similarity can help in studying both organisms.
79
What is the treatment for Entamoeba polecki infections?
Combination of metronidazole (Flagyl) and diloxanide furoate (furamide)
## Footnote
This treatment approach is effective for managing infections.
80
How many nuclei does the trophozoite of Entamoeba polecki have?
1
## Footnote
This characteristic is important for microscopic identification.
81
What is the karyosome of the trophozoite described as?
Small and central
## Footnote
This feature aids in the identification of the organism.
82
What type of inclusions are found in the trophozoite of Entamoeba polecki?
Ingested bacteria; Other food particles
## Footnote
These inclusions can indicate the feeding habits of the organism.
83
How many nuclei does the cyst of Entamoeba polecki have?
1
## Footnote
This characteristic is consistent with the trophozoite stage.
84
What is the karyosome of the cyst described as?
Small and central
## Footnote
This similarity to the trophozoite's karyosome is notable.
85
What cystoplasmic inclusions are present in the cyst of Entamoeba polecki?
Chromatoid bars; Diffuse glycogen mass present in young cysts
## Footnote
These inclusions can help differentiate between stages of the organism.
86
What is the habitat of Endolimax nana?
Cecum of humans
## Footnote
Endolimax nana primarily resides in the cecum, which is part of the large intestine.
87
How is Endolimax nana transmitted?
Fecal-oral (contaminated food/water)
## Footnote
Transmission occurs when food or water contaminated with feces is ingested.
88
What is the size range of the trophozoite form of Endolimax nana?
6-15 micrometers
## Footnote
The trophozoite is the active, motile form of the organism.
89
Describe the nucleus of the trophozoite of Endolimax nana.
Uninucleated with an irregular karyosome
## Footnote
The nucleus is single and has an irregularly shaped central body.
90
What type of motility is observed in the trophozoite of Endolimax nana?
“Slug-like” motility
## Footnote
This refers to the slow, gliding movement characteristic of this organism.
91
What is the size range of the cyst form of Endolimax nana?
5-10 micrometers
## Footnote
Cysts are the dormant, resistant form of the organism.
92
How many nuclei can be found in the cyst of Endolimax nana?
1-4 nuclei
## Footnote
Cysts can contain multiple nuclei, which can be used to identify the organism.
93
What unique shape is associated with the nucleus of the cyst of Endolimax nana?
“Cross-eye” or “punched out” nucleus
## Footnote
This distinctive appearance aids in microscopic identification.
94
What type of chromatoidal bodies do cysts of Endolimax nana have?
Comma-shaped chromatoidal bodies
## Footnote
These bodies are indicative of the cyst's structure.
95
What is the appearance of the cytoplasm in the cyst of Endolimax nana?
“Ground-glass” cytoplasm
## Footnote
This term describes the translucent and granular appearance of the cyst's cytoplasm.
96
What is the clinical importance of Endolimax nana?
Non-pathogenic
## Footnote
Endolimax nana does not cause disease and is often found in healthy individuals.
97
In which areas is Endolimax nana often found?
Areas where E.coli is present
## Footnote
The presence of E.coli is often associated with the same environments where Endolimax nana is found.
98
What is the habitat of Iodamoeba bütschlii?
Cecum of humans, more common in warm climates
## Footnote
Iodamoeba bütschlii is typically found in the cecum, which is part of the large intestine.
99
How is Iodamoeba bütschlii transmitted?
Fecal-oral (contaminated food/water)
## Footnote
Transmission occurs when individuals ingest contaminated food or water.
100
What are the key characteristics of the trophozoite form of Iodamoeba bütschlii?
* 6-15 micrometers
* Single nucleus
* Large karyosome
* Perikaryosomal central chromatin granules
* Pink glycogen mass (1/2 or 1/3 of cell size)
## Footnote
The trophozoite is the active, feeding stage of the organism.
101
What are the key characteristics of the cyst form of Iodamoeba bütschlii?
* 6-15 micrometers
* Single nucleus
* Large glycogen mass (more than 1/2 or 2/3 of the cell)
* Stains mahogany-brown with Lugol’s iodine
## Footnote
The cyst form is a dormant stage that can survive outside the host.
102
Is Iodamoeba bütschlii pathogenic?
Non-pathogenic but may be mistaken for pathogenic amoebas in fecal samples
## Footnote
While Iodamoeba bütschlii itself does not cause disease, it can be confused with harmful amoebas during diagnostics.
103
What is the habitat of Entamoeba gingivalis?
Oral cavity, including gums, tonsillar crypts, and pyorrhea pockets
## Footnote
Entamoeba gingivalis is specifically associated with areas of the mouth that may be affected by poor hygiene.
104
How is Entamoeba gingivalis transmitted?
Direct contact, such as kissing, shared utensils, or droplet spray
## Footnote
This mode of transmission highlights the communicable nature of the organism.
105
What is the only morphologic structure of Entamoeba gingivalis?
Trophozoite
## Footnote
Trophozoites are the active, feeding stage of the organism.
106
What is the size range of Entamoeba gingivalis trophozoites?
5-15 micrometers
## Footnote
This size range is important for microscopic identification.
107
What is a distinguishing feature of Entamoeba gingivalis?
Ingests leukocytes
## Footnote
This characteristic helps differentiate it from other amoebas.
108
Does Entamoeba gingivalis form cysts?
No
## Footnote
The absence of a cyst form differentiates it from many other protozoan parasites.
109
Is Entamoeba gingivalis pathogenic?
Non-pathogenic
## Footnote
It is associated with poor oral hygiene but does not cause disease.
110
With which organisms is Entamoeba gingivalis often found?
Trichomonas tenax and Candida albicans
## Footnote
These organisms are also associated with oral conditions.
111
What is the transmission route for Endolimax nana and Iodamoeba bütschlii?
Fecal-oral transmission
## Footnote
These organisms are intestinal commensals and differ from Entamoeba gingivalis.
112
What is a common confusion during microscopic examination involving Entamoeba gingivalis?
May be confused with harmful parasites
## Footnote
This confusion highlights the importance of accurate identification in laboratory settings.
113
What is the habitat of Naegleria fowleri?
Fresh-water and moist soil
## Footnote
Naegleria fowleri thrives in warm freshwater environments, such as lakes and hot springs.
114
How is Naegleria fowleri transmitted?
Instillation of trophozoites through the nose
## Footnote
This typically occurs when swimming in contaminated water.
115
What is the size range of the trophozoite form of Naegleria fowleri?
8-22 micrometers
## Footnote
Trophozoites are the active, feeding form of the amoeba.
116
Describe the morphology of Naegleria fowleri trophozoites.
Elongate with a broad anterior and tapered posterior; slug-like motility with blunt pseudopodia
## Footnote
These features aid in movement and feeding.
117
What are the characteristics of Naegleria fowleri cysts?
Round (9-12 micrometers), thick-walled, single nucleus with granular cytoplasm
## Footnote
Cysts are a dormant form that can survive in harsh conditions.
118
What disease does Naegleria fowleri cause?
Primary Amoebic Meningoencephalitis (PAM)
## Footnote
PAM is a rapidly fatal brain infection.
119
What are the symptoms of Primary Amoebic Meningoencephalitis (PAM)?
* Headache
* Fever
* Stiff neck
* Coma (Kernig’s sign)
## Footnote
Symptoms typically appear within days after infection.
120
What is the typical time frame for death after PAM onset?
3-6 days
## Footnote
Rapid intervention is crucial for survival.
121
What is the key to survival in cases of PAM?
Early diagnosis
## Footnote
There is no effective treatment for PAM.
122
What are the three morphologic forms of Naegleria fowleri?
* Amoeboid trophozoites
* Flagellate form
* Cysts
## Footnote
Each form has distinct characteristics and roles in the life cycle.
123
What are some prevention methods for Naegleria fowleri infections?
* Avoid contact with stagnant or thermal waters
* Adequate chlorination of public water supplies
* Salination of public pools up to 0.7%
* Public education on water safety
## Footnote
These measures can significantly reduce the risk of infection.
124
What form of Naegleria fowleri is found in humans?
Ameboid trophozoites
## Footnote
This form is responsible for causing disease in humans.
125
How do trophozoites replicate in the human body?
By binary fission
## Footnote
This asexual reproduction allows rapid population growth.
126
What happens to flagellate trophozoites when transferred to water?
They form in vitro but do not divide
## Footnote
They can convert back into ameboid trophozoites to resume reproduction.
127
What is the entry point for Naegleria fowleri to infect humans?
Nasal mucosa
## Footnote
The amoeba migrates to the brain, leading to rapid tissue destruction.
128
What other disease is caused by a different amoeba that can enter through the skin or eyes?
Granulomatous Amoebic Meningoencephalitis (GAE)
## Footnote
GAE is a chronic brain infection caused by Acanthamoeba.
129
What are the symptoms of Granulomatous Amoebic Meningoencephalitis (GAE)?
* Headache
* Seizures
* Altered mental status
* Necrosis
## Footnote
GAE progresses slowly compared to PAM.
130
What eye infection is associated with Acanthamoeba?
Acanthamoeba keratitis
## Footnote
This infection is often linked to contact lens use.
131
What is a prevention measure for Acanthamoeba keratitis?
Proper contact lens hygiene
## Footnote
This includes cleaning and storing lenses correctly.
132
True or False: There is a definitive drug for granulomatous amoebic encephalitis.
False
## Footnote
Treatment options are limited and primarily supportive.
133
What is the size of the trophozoite of Acanthamoeba culbrtsoni?
30 micrometers
## Footnote
Trophozoites are the active, feeding stage of the organism.
134
What distinguishes the nucleus of the trophozoite of Acanthamoeba culbrtsoni?
Prominent; nucleus with a large nucleolus
## Footnote
The nucleolus is a region within the nucleus involved in ribosome production.
135
What is the size of the cyst of Acanthamoeba culbrtsoni?
20+ micrometers
## Footnote
Cysts are the dormant, resistant stage of the organism.
136
Describe the structure of the cyst of Acanthamoeba culbrtsoni.
Double-walled with polyhedral inner endocyst and smooth/slightly wrinkled outer ectocyst
## Footnote
The double-walled structure provides protection against environmental stress.
137
Where is the nucleus located in the cyst of Acanthamoeba culbrtsoni?
Centrally located nucleus with a large karyosome
## Footnote
The karyosome is a mass of chromatin within the nucleus.
138
What is Acanthamoeba polyphaga?
Acanthamoeba polyphaga is a species of free-living amoeba.
139
What is the size of the trophozoite of Acanthamoeba polyphaga?
23 micrometers
140
What type of pseudopodia does the trophozoite of Acanthamoeba polyphaga have?
Broad hyaline lobopodia
141
What is a prominent feature of the trophozoite of Acanthamoeba polyphaga?
Prominent uroid process
142
How many contractile vacuoles does the trophozoite of Acanthamoeba polyphaga possess?
Single contractile vacuole
143
What type of nucleus does the trophozoite of Acanthamoeba polyphaga have?
Vesicular nucleus with centrally located endosome
144
What are the characteristics of the cyst of Acanthamoeba polyphaga?
Double-walled, polyhedral or stellate endocysts, wrinkled ectocyst
145
What is the shape of the trophozoite of Acanthamoeba costelani?
Elongated shape
## Footnote
Trophozoites are the active feeding form of the organism.
146
What is the size of the cyst of Acanthamoeba costelani?
16 micrometers
## Footnote
Cysts are the dormant, resistant form of the organism.
147
What is the shape of the cyst of Acanthamoeba costelani?
Polyhedral
## Footnote
Polyhedral refers to a shape with many faces, typical for cysts.
148
Describe the ectocysts of Acanthamoeba costelani cysts.
Rippled or wrinkled
## Footnote
The ectocyst is the outer layer of the cyst, which provides protection.
149
What is the length range of the trophozoite of Acanthamoeba astronyxis?
25-60 micrometers
150
What are conspicuous features of the trophozoite of Acanthamoeba astronyxis?
Conspicuous food vacuoles and endoplasm containing small-yellowish refractile bodies
151
What is the shape of the cyst of Acanthamoeba astronyxis?
Biconcave cyst
152
What are the characteristics of the ectocyts in Acanthamoeba astronyxis cyst?
Folded ectocyts
153
What type of endocyst does Acanthamoeba astronyxis have?
Stellate endocysts
154
What is the size range of the cyst of Acanthamoeba astronyxis?
14-25 micrometers
155
How many prominent nuclei does the cyst of Acanthamoeba astronyxis have?
Single prominent nucleus
