Protozoa (EXAM IV) Flashcards
1
Q
Protozoa have typically been classified as:
A
Parasites
2
Q
What is a parasite?
A
An organism that lives on or within another organism (the host) and benefits from the association while harming the 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
Protozoa can be described as a:
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; aquatic; 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; with a wall & low metabolic activity
13
Q
Describe the metabolic activity of protozoa during encystation:
A
Low metabolic activity
14
Q
List the function of cysts: (3)
A
- Protection from changes in environment
- Sites for nuclear reorganization & cell division
- Transfer from one host to another
15
Q
Escape from vegetative form from cyst:
A
Encystation
16
Q
Encystation is usually triggered by:
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 or protozoa:
A
Some are nonmotile some are motile
19
Q
The motile species of protozoa use one of the following:
A
-Cilia
-Flagella
-Psuedopodia
20
Q
Psuedopodia are:
A
Cytoplasmic extensions
21
Q
Reproduction of protozoa may be:
A
Asexual or sexual
22
Q
Asexual reproduction of protozoa typically occurs through:
A
Binary fission
23
Q
Describe the 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
26
Zooflagellates are motile due to:
One or more flagella
27
Species of protozoa that cause Giardiasis:
Giardia Lamblia
28
Giardiasis is a:
Gastrointestinal disorder
29
Species of protozoa that cause Trichomoniasis:
Trichomonas Vaginalis
30
Trichomoniasis is a:
Sexually transmitted disease
31
Hemoflagellates that are important blood pathogens:
Trypanosomes
32
Trypanosomes are:
Hemoflagellates (AKA blood parasites)
33
Give an example of a Trypanosome:
African sleeping sickness
34
Most common cause of epidemic waterborne diarrheal disease:
Giardiasis
35
Giardiasis is a _____ disorder
Gastrointestinal disorder
36
Giardia lamblia forms ____ & _____
Cysts & trophozoites
37
Giardia lamblia forms cysts & trophozoites. The trophozoites attach to _____ & interfere with ____
intestinal epithelium; nutrient absorption
38
Discuss the transmission of Giardia lamblia:
Cyst-contaminated water
39
Discuss the reservoirs of Giardia lamblia:
numerous animal reservoirs & asymptomatic carriers are common
40
The clinical manifestations of ________ include- severe diarrhea, epigastric pain, cramps, voluminous flatulence & anorexia:
Acute giardiasis
41
The clinical manifestations of _____ include- intermittent diarrhea with periodic appearance and remission of symptoms:
Chronic gastritis
42
What antiprotozoal agents are used for the treatment of giardiasis?
Metronidazole
43
How might one prevent contraction of giardiasis?
Avoiding contaminated water of puriy it by boiling or filtering (cysts are resistant to chlorine treatment)
44
The cysts formed in Giardia lamblia are resist to:
Chlorine treatment
45
One of the most common sexually transmitted diseases:
Trichomonas vaginalis
46
Trichomonas vaginalis is found in ____ % of women
15%
47
Trichomonas vaginalis lacks a ____ stage but does produce ____
Cyst stage; trophozoites
48
Discuss the clinical manifestations of Trichomoniasis:
1. accumulation of leukocytes at site of infection
2. In female, results in yellow purulent vaginal discharge and itching
3. In males usual asymptomatic or burning urination
49
Discuss how we diagnose trichomonas vaginalis:
Observation of parasite in vaginal discharge, semen or urine
50
What is the treatment of trichomonas vaginalis:
Antiparasite therapy of metrodiazole
51
Resides in the mouth; usually associated with poor oral hygiene:
Trichomonas tenax
52
Trichomonas tenar aspiration is associated with:
Pneumonia
53
Hemoflagellate diseases are caused by:
flagellated protozoa
54
Two major groups of flagellated protozoa include:
Leishmanias & trypanosomes
55
Hemoflagellate diseases are transmitted by:
bites of infected arthropods
56
Hemoflagellate disease infect:
Blood & tissues of humans
57
Also called African sleeping sickness:
African trypanosomiasis
58
African trypanosomiasis is transmitted by:
Tsetse flies
59
The reservoirs of African trypanosomiasis include:
Domestic cattle & wild animals
60
African trypanosomiasis symptoms are characterized as:
Chronic bloodstream infections with bouts of parasitemia
61
what happens after months to years with African trypanosomiasis infection?
CNS invasion
62
The clinical manifestations of African trypanosomiasis include:
Interstitial inflammation and necrosis within lymph node and small blood vessels of brain & heart, leading to lethargy & death within 1 to 3 years
63
Disease characterized by interstitial inflammation & necrosis within lymph nodes and small blood vessels of brain & heart leading to lethargy & death in about 1 to 3 years:
African trypanosomiasis
64
Disease characterized by interstitial inflammation & necrosis within lymph nodes and small blood vessels of brain & heart leading to lethargy & death in about 1 to 3 years:
African trypanosomiasis
65
The causative agent of African trypanosomiasis is:
Trypanosoma Brucei
66
How is African trypanosomiasis diagnosed?
observation of motile parasites in blood
67
Treatment of African trypanosomiasis includes:
Drug therapy during systemic stage, but not as effective when CNS is involved
68
Describe the vaccination for African trypanosomiasis:
Vaccine not useful due to antigenic variation
69
Why is the vaccine for African trypanosomiasis not useful?
Due to antigenic variation due to genetic rearrangements
(multiple silent copeis & 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
73
Chagas disease is transmitted by:
Kissing bug (Reduviid bug)
74
Reservoirs of Chagas disease include:
Domestic cattle & other animals
75
In endemic regions, who is typically infected with chugs disease
Most people in population infected in childhood
76
Describe the progression of chugs disease:
Early disease= mild; small % develop complications 10-20 years later
77
When would individuals develop complications from chagas disease?
10-20 years later
78
Chagas disease can result in heart disease and other disorder due to destruction of parasitize cells in the:
Liver, spleen, lymph nodes & CNS
79
Chagas disease can result in heart disease & other disorders due to _____ in the liver, spleen, lymph nodes & CNS
Destruction of parasitized cells
80
____ & ____ may occur in chagas disease due to damage to nerves in the GI tract
Megaesophagus & megacolon
81
____ may occur in chagas disease due to damage to heart muscle
Cardiomyopathy
82
Cardiomyopathy may occur in chagas disease due to damage to heart muscle, which may ultimately result in:
Sudden death from arrhythmia
83
What is the treatment for Chagas disease?
No available for late complications; vaccines not useful due to antigenic variation
84
Why are vaccines not useful against chagas disease?
Antigenic variation due to genetic switching
85
What is causative agent of Chagas disease?
Trypanosoma cruzi
86
Describe how the parasite is discharged in chagas disease:
Discharged in feces
87
How does the vector enter the human body in chagas disease?
Enters the human body through bite wound
88
Disease caused by Leishmania species (several, with different tissue tropisms):
Leishmaniasis
89
Leishmaniasis is transmitted by:
Sandflies when they take a blood meal (usually tropical)
90
What are the reservoirs for leishmania species?
Canines & rodents
91
Leishmania survives & differentiated in:
Macrophages (superoxide dismnutase)
92
The three forms of Leishmaniasis infection include:
1. Mucocutaneous
2. Cutaneous
3. Visceral
93
Form of leishmaniasis that involves lesions of the mouth, nose, throat & skin that cause extensive scarring & disfigurement:
Mucocutaneous leishmaniasis
94
Form of leishmaniasis that involves papules that develop into crustated ulcers:
Cutaneous leishmaniasis
95
Cutaneous leishmaniasis occurs with ____ & ____
Scarring & permanent immunity
96
Form of leishmaniasis that involves tissue macrophage dysfunction with clinical manifestations of intermittent fever & enlargement of spleen or liver:
Visceral leishmaniasis
97
Visceral leishmaniasis involves _____ dysfunction
Tissue macrophage
98
Recovery from visceral leishmaniasis provides:
Permanent immunity
99
Treatment of leishmaniasis includes:
Several types of drugs available including amphotericin B, the polyene antifungal agent
100
What are ways to control contraction of leishmaniasis?
Vector & reservoir control along wit epidemiological surveillance
101
Amoebiasis (Amoeboid protozoa) causes:
Amoebic dysentery
102
The causative agent of Amoebiasis:
Entamoeba histolytica
103
Transmission of Amoebiasis occurs through:
Ingestion of cysts
104
The clinical manifestations of amoebiasis includes:
Asymptomatic to fulminating dysentery, exhaustive diarrhea, and abscesses of the liver, lungs & brain
105
How is Amoebiasis diagnosed?
Observation of trophozoites in fresh warm stools or cysts in ordinary stools & serological tests
106
What treatment may be used for Amoebiasis?
Metronidazole therapy
107
Why is metronidazole therapy effective against Amoebiasis?
Because amoebas carry out anaerobic metabolism & the drug penetrates tissue well to destroy invasive pathogens
108
What is one way to control the contraction of Amoebiasis?
Avoiding contaminated water & food and hyperchlorination/iodination of water supplies to destroy waterborne cysts
109
Phylum Apicomplexa lack _____ except for ___ & ____
Locomotor organelles; male gamets & zygotes
110
All Phylum Apicomplexa contain:
Apical complex
111
Arrangement fibrils, tubules, vacuoles & other organelles at one end of the cell describe:
Apical complex of Phylum Apicomplexa
112
The spirally arranged fibers:
Conoid
113
Contains materials that are secreted and aid in penetration of host cell:
Rhoptry
114
The life cycle of _____ invovles two different hosts, (usually mammal & mosquito)
Apicomplexan
115
The apicomplexan life cycle involve both:
Sexual & asexual phases
116
The asexual phase of the apicomplexan life cycle involving a rapid series of mitotic event producing infective organisms:
Schizogony
117
What is produced during the sexual phase of apicomplexan life cycles?
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
119
Apicomplexan = ______
Sporozoan
120
Important sporozoan (apicomplexan) generas include:
1. Plasmodium
2. Cryptosporidium
3. Toxoplasma
121
The important sporozoan (apicomplexan) responsible for malaria:
Plasmodium
122
The important sporozoan (apicomplexan) responsible for cryptosporidiosis:
Cryptosporidium
123
The important sporozoan (apicomplexan) 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. Malaria
4. P. Ovale
127
Malaria is transmitted 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
131
P. Vivax & P. Ovale form _____ which are the _____ forms within liver cells
Hypnozoites; dormant
132
The hypnozoites formed by p. Vivax & 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 & fever
134
The periodic attacks of chills & 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; multiple 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 & 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 & how do they function?
Chloroquine & other quinine based drugs- these block heme detoxification in plasmodium food vacuole
141
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
143
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 & transmitted by same Ixodes tick as Borrelia burgdorferi:
Babesia
146
Babesia is caused by:
Babesia species
147
Infections of Babesia range from______ & can be described as:
Subclinical to severe disease & "summer flu"
148
Describe what happens when protozoa infect red blood cells & babesia:
Once protozoa infect red blood cells they cause fever upon release
149
Babesia infection is similar to _____ but there is no ____
Malaria; no intermediate liver stage
150
What is the reservoir for babesia?
The white-footed mouse (NOT HUMANS)
151
Diagnosis of babesia is by:
Microscopy of Giemsa-stained blood samples & PCR
152
What is the treatment of babesia?
Clindamycin + quinine (different from malaria)
153
The causative agent of toxoplasmosis:
Toxoplasma gondii
154
Transmission of toxoplasmosis occurs by:
Ingestion of undercooked meat, congenital transfer, blood transfusion, tissue transplant & ingestion of cat feces
155
Toxoplasma gondii invade:
macrophages
156
What is the definitive host of toxoplasma gondii?
Cats
157
What are two common modes of transmission of Toxoplasmosisn for humans?
(list the most common1 mode first)
1. Undercooked meat containing tissue cysts
2. Humans handling kitty litter or soil
158
The clinical manifestations of toxoplasmosis include:
-Usually asymptomatic (in greater than 99%) or resembles mono
-Can be fatal in immunocompromised hosts (mass lesions in the brain)
-congenital infections
159
Treatment for toxoplasmosis include:
Antiparasite therapy for immunocompromised hosts
160
Control of toxoplasmosis contraction includes:
-Minimizing exposure by avoidance of raw meat & eggs, washing hands after working in soil & cat-handling practices
-Women screened for anti toxoplasma antibody at marriage or very early in pregnancy, if positive, fetus is protected
