Protozoa- Exam IV Flashcards
(161 cards)
1
Q
Protozoa have typically been classified as:
A
parasites
2
Q
What’s a parasite?
A
an organism that lives on or within another organism (the host) and benefits from the associated while harming its host
3
Q
Where does a parasite typically obtain its nutrients from?
A
host
4
Q
Types of parasites include:
A
protozoa & helminths
5
Q
Describe protozoa:
A
Diverse group of eukaryotic microbes
6
Q
How are protozoa related?
A
related only by their simple organization
7
Q
The simple organization relating protozoa includes:
A
unicellular or multicellular without specialized tissues
8
Q
Most protozoa are ___ in ___ environments or on ___ .
A
free-living in aquatic environments; decaying organic matter
9
Q
Some protozoa are considered ___.
A
parasitic
10
Q
Many protozoa are capable of:
A
encystation
11
Q
Formation of a cyst:
A
encystation
12
Q
Formation of a cyst by protozoa involves a ___ state with:
A
resting state; a wall and low metabolic activity
13
Q
Describe the metabolic activity of protozoa during encystation:
A
low metabolic activity
14
Q
List the functions of cysts (3):
A
- protection from changes in environment
- sites for nuclear reorganization and cellular division
- transfer from one host to another
15
Q
Escape from vegetative form from cyst:
A
excystation
16
Q
Encystation is usually triggered by: (2)
A
- return to favorable environment
- entry into new host
17
Q
What is the vegetative form released by parasitic species?
A
trophozoite
18
Q
Discuss the locomotion of protozoa:
A
some are non-motile and some are motile
19
Q
The motile species of protozoa use one of the following:
A
- cilia
- flagella
- pseudopodia
20
Q
Pseudopodia are:
A
cytoplasmic extensions
21
Q
Reproduction of protozoa may be:
A
asexual or sexual
22
Q
Asexual reproduction of protozoa usually occurs through:
A
binary fission
23
Q
describe binary fission:
A
mitosis followed by cytokinesis
24
Q
Sexual reproduction of protozoa typically occurs through:
A
conjugation
25
Describe conjugation:
exchange of gametic nuclei between paired protozoa of opposite mating types
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Zooflagellates are motile due to:
one or more flagella
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Species of protozoa that causes giardiasis:
giardia lamblia
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Giardiasis is a:
gastro-intestinal disorder
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Species of protozoa that causes trichomoniasis:
trichomonas vaginalis
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Trichomoniasis is a:
STD
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Hemoflagellates that are important blood pathogens:
trypanosomes
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Trypanosomes are:
hemoflagellates
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Hemoflagellates AKA:
blood parasite
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Give an example of a trypanosome:
African sleeping sickness
35
Most common cause of epidemic water-borne diarrheal disease:
giardiasis
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Giardiasis is a ___ disorder
GI
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Giardia lamblia forms ___ & ____
cysts and trophozoites
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Giardia lamblia form cysts and trophozoites. The trophozoites attach to ___ and interfere with ___.
intestinal epithelium; nutrient absorption
39
Discuss the transmission of Giardia lamblia:
cyst-contaminated water
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Discuss the reservoirs of Giardia lamblia:
numerous animal reservoirs & asymptomatic carriers
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The clinical manifestations of ____ include severe diarrhea, epigastric pain, cramps, voluminous flatulence, and anorexia
acute giardiasis
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The clinical manifestations of ___ include intermittent diarrhea with periodic appearance and remission of symptoms
chronic gastritis
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What anti-protozoal agents are used for treatment of giardiasis?
metronidazole
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How might one prevent contracts of giardiasis?
avoiding contaminated water or purify it by boiling or filtering (cysts are resistant to chlorine treatment)
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The cysts formed in Giardia lamblia are resistant to:
chlorine treatment
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One of the most common sexually transmitted diseases:
trichomonas vaginalis
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Trichomonas vaginalis is found in:
15% of all women
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Trichomonas vaginalis lacks a ___ stage but does produce ___.
cyst stage; trophozoites
49
Discuss the clinical manifestations of trichomoniasis:
1. accumulation of leukocytes at site of infection
2. in females, results in yellow purulent vaginal discharge and itching
3. in males, usually asymptomatic or burning urination
50
Discuss how we diagnose trichomoniasis?
observation of parasite in vaginal discharge, semen, or urine
51
What is the treatment for trichomoniasis?
anti-parasite therapy of metrodiazole
52
Resides in the mouth and is usually associated with poor oral hygiene:
trichomonas tenax
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Trichomonas tenar aspiration is associated with:
pneumonia
54
Hemoflagellate diseases are caused by:
flagellated protozoa
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Two major groups of flagellate protozoa include:
leishmanias & trypanosomes
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Hemoflagellate diseases are transmitted by:
bites of infected arthropods
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Hemoflagellate diseases infect:
blood and tissues of humans
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Also called African sleeping sickness:
african trypanosomiasis
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african trypanosomiasis is transmitted by:
tsetse flies
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The reservoirs of african trypanosomiasis include:
domestic cattle and wild animals
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african trypanosomiasis symptoms are characterized by:
chronic bloodstream infection with bouts of parasitemia
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What happens after months to years with african trypanosomiasis infection?
CNS invasion
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The clinical manifestations of african trypanosomiasis include:
Interstitial inflammation and necrosis within lymph nodes and small blood vessels of brain and heart, leading to lethargy and death within one to three years
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Disease characterized by interstitial inflammation and necrosis within lymph nodes and small blood vessels of brain and heart leading to lethargy and death within about 1-3 years:
african trypanosomiasis
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The causative agent of african trypanosomiasis is:
trypanosoma brucei
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How is african trypanosomiasis diagnosed?
observation of motile parasites in the blood
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treatment of african trypanosomiasis includes:
drug therapy during systemic stage, but not as effective when CNS is involved
68
Describe vaccination for african trypanosomiasis:
Vaccine not useful due to antigenic variation
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Why is a vaccine not useful for african trypanosomiasis?
Due to antigenic variation due to genetic rearrangements (multiple silent copies and one expression locus)
70
What is the intermediate host between animal reservoir and humans for african trypanosomiasis?
tsetse fly
71
What determines the disease range of african trypanosomiasis?
tsetse fly
72
American trypanosomiasis (Latin America; sporadic in southern USA):
Chagas Disease
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Chugs disease is transmitted by:
Kissing bug (Reduviid bug)
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Reservoirs of Chagas disease include:
domestic cattle and other animals
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In endemic regions, who is typically infected with chagas disease?
most people in population infected in childhood
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Describe the progression of chagas disease:
early disease = mild; small % develop complications 10-20 years later
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When would people develop complications from chagas disease?
10-20 years later
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chagas disease can result in heart disease and other disorders due to destruction of parasitized cells in the:
liver, spleen, lymph nodes, and CNS
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Chana's Disease can result in heart disease and other disorders due to ____ in the liver, spleen, lymph nodes and CNS
destruction of parasitized cells
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___ & ___ may occur in chagas disease due to damage to nerves in the GI tract:
megaesophagus & megacolon
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___ may occur in chagas disease due to damage to heart muscle
cardiomyopathy
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cardiomyopathy may occur in chagas disease due to damage of heart muscle which can ultimately result in:
sudden death from arrhythmia
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What is the treatment for chagas disease?
No treatment available for late complications, vaccines not useful due to antigenic variation
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Why are vaccines not useful against chagas disease?
antigenic variation due to genetic switching
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What is the causative agent of chagas disease?
Trypanosoma cruzi
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Describe how the parasite is discharged in chagas disease:
discharged in feces
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How does the vector enter the human body in chagas disease?
enters the human body through bite wound
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disease caused by leishmania species (several, with different tissue tropisms)
leshmaniasis
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Leishmaniasis is transmitted by:
sand flies when they a blood meal (usually tropical)
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What reservoirs for leishmania species?
canines and rodents
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Leishmania survives and differentiates in:
macrophages (superoxide dismutase)
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The three forms of leishmaniasis infection include:
1. mucocutaneous
2. cutaneous
3. visceral
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Form of leishmaniasis that involves lesions of the mouth, nose, throat, and skin, that cause extensive scarring and disfigurement:
mucocutaneous leishmaniasis
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Form of leishmaniasis that involves papules that develop into crustated ulcers:
cutaneous leishmaniasis
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cutaneous leishmaniasis healing occurs with ___ & ___
scarring and permanent immunity
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Form of leishmaniasis that involves tissue macrophage disfunction with clinical manifestations of intermittent fever and enlargement of spleen and liver:
visceral leishmaniasis
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Visceral leishmaniasis ____ disfunction
tissue macrophage
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Recovery from visceral leishmaniasis provides:
permanent immunity
99
Treatment of leishmaniasis includes:
several types of drugs available including amphotericin B, the polyene anti-fungal agent
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What are ways to control contraction of leishmaniasis?
vector and reservoir control, along with epidemiological surveillance
101
Amoebiasis (Amoeboid protozoa) causes:
amoebic dysentery
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The causative agent of amoebiasis:
entamoeba histolytica
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transmission of amoebiasis occurs through:
ingestion of cysts
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The clinical manifestations of amoebiasis includes:
asymptomatic to fulminating dysentery, exhaustive diarrhea, and abscesses of the liver, lungs, and brain
105
How is amoebiasis diagnosed?
observation of trophozoites in fresh warm stools or cysts in ordinary stools, and serological tests
106
What treatment may be used for amoebiasis?
metronidazole therapy
107
Why is metronidazole therapy effective against amoebiasis?
amoebas carry out anaerobic metabolism and the drug penetrates tissue well to destroy invasive pathogens
108
What is one way to control the contraction of amoebiasis?
avoiding contaminated water and food and hyperchlorination/iodination of water supplies to destroy waterborne cysts
109
Phylum apicomplexa lack ____ except for ___ or ___
locomotor organells; male gametes and zygotes
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All Phylum apicomplexa contain:
apical complex
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Arrangement fibrils, tubules, vacuoles, and other organelles at one end of the cell:
apical complex
112
spirally arranged fibers:
conoid
113
Contains materials that are secreted and aid in penetration of host cell:
rhoptry
114
The lifecycle of ___ involves two different hosts (usually mammal and mosquito):
apicomplexan life cycle
115
The apicomplexan life cycle involves both:
sexual and asexual phases
116
The asexual phase of the apicomplexan life cycle involving a rapid series of mitotic events producing infective organisms:
schizogeny
117
What is produced during the sexual phase of the apicomplexan life cycle?
oocyst
118
Describe the oocyst produced during the sexual phase of the apicomplexan life cycle:
thick-walled diploid structure that undergoes meiosis to produce haploid spores
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apicomplexan=
sporozoan
120
Important sporozoan (ampicomplexan) generas include:
1. plasmodium
2. cryptosporidium
3. toxoplasma
121
The sporozoan (ampicomplexan) responsible for malaria:
plasmodium
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The sporozoan (ampicomplexan) responsible for cryptosporidiosis:
cryptosporidium
123
The sporozoan (ampicomplexan) responsible for toxoplasmosis:
toxoplasma
124
Malaria is caused by four species of:
plasmodium
125
What species of plasmodium that causes malaria is most virulent?
plasmodium falciparum
126
What are the four species of plasmodium that cause malaria?
1. P. falciparum
2. P. vivax
3. P. malariae
4. P. ovale
127
Malaria is treated by bite of an infected:
female anopheles mosquito
128
What is the reservoir of malaria?
humans
129
What is the intermediate host of malaria:
humans asexual reproduction
130
What is the definitive host of malaria?
mosquito sexual reproduction
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P. Vivax and P. ovale form ____ which are the ___ forms within liver cells
hypnozoites; dormant forms
132
The hypnozoids formed from P. Vivax and P. ovale within liver cells cause:
recurrent malaria (months to years after initial disease)
133
The clinical manifestations of malaria include:
periodic attacks of chills and fever
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The periodic attacks of chills and fever seen with malaria coincide with:
RBC lysis and merozoite release, which stimulates cytokine production
135
describe the hepatocellular cycle involved in malaria infection:
8-14 days; multiply asexually
136
describe the erythrocyte cycle involved in malaria infection:
2-3 days; multiply asexually
137
In a malaria infection, a small number of merozoites develop into:
gametocytes
138
How is malaria diagnosed?
demonstration of parasites within Wright- or Giemsa-stained red blood cells and serological tests (but these are of little value in acutely ill patient)
139
What is the treatment for malaria?
antimalarial drugs
140
What are the classic antimalarial drugs and how do they function?
chloroquine and other quinine based drugs- these block heme detoxification in plasmodium food vacuole
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In treatment of malaria, ____ resistance is widespread due to the drug being pumped out of the vacuole
chloroquine resistance
142
What is the mechanism of chloroquine resistance in malaria infections?
drug pumped out of vacuole
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For individuals traveling to high endemic malaria areas, what is recommended?
1. chemoprophylaxis
2. netting
3. insect repellants
144
What is characteristic of early stages of malarial infection?
early ring formation
145
Endemic to the USA and transmitted by same exodus tick as borrelia burgdoferri:
babesia
146
Babesia is caused by:
babesia species
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Infections of babesia range from:
subclinical to severe disease
148
Infections of babesia can be described as:
"summer flu"
149
Describe what happens when protozoa infect red blood cells in babesia:
once protozoa infect red blood cells they cause fever upon release
150
Babesia infection is similar to ___ but there is no ___
malaria; intermediate liver stage
151
What is the reservoir for babesia?
White-footed mouse (NOT HUMANS)
152
Diagnosis of babesia is by:
microscopy of Giemsa-stained blood samples & PCR
153
What is the treatment of babesia?
clindamycin + quinine (different from malaria)
154
The causative agent of toxoplasmosis:
toxoplasma gondii
155
Transmission of toxoplasmosis is by:
ingestion of undercooked meat, congenital transfer, blood transfusion, tissue transplant and ingestion of cat feces
156
Toxoplasma gondii invade:
macrophages
157
What is the definitive host of toxoplasma gondii?
Cats
158
What are two common modes of transmission of toxoplasmosis for humans (list the most common one first)?
1. undercooked meat containing tissue cysts
2. humans handling kitty litter or soil
159
The clinical manifestations of toxoplasmosis include:
- usually asymptomatic (in greater than 99% or resembles mono
- can be fatal fatal in immunocompromised hosts (mass lesions in the brain)
- congenital infections
160
Treatment for toxoplasmosis includes:
antiparasite therapy for immunocompromised patients
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Control of toxoplasmosis contraction includes:
- minimizing exposure by avoidance of: raw meat and eggs, washing hands after in soil, and cat handling practices
- women screened for anti toxoplasma antibody at marriage or very early in pregnancy
