Micro 2 - Midterm Flashcards
(120 cards)
1
Q
What are the factors that influence the distribution of parasitic diseases?
A
Rapid Travel
Immigration
Increased # of immunocompromised patients
2
Q
What is the definition of Infection?
A
Invasion and multiplication of a pathogenic parasite in the body with accompanying rxn by the host
3
Q
Define Infestation
A
Parasitic organisms or arthropods that live on the surface of a host without multiplication.
4
Q
Any damage of a host tissues or organs that leads to malfunction of an organ caused by a parasite is describing…
A
Disease
5
Q
What is a Vector
A
Any arthropod or other living organism that transport a pathogenic microorganism from an infected to a non-infected host
6
Q
What is the difference between a final/definitive host and an intermediate host?
A
Final = parasite passes sexual reproduction phase Intermediate = passes larval stage or asexual reproduction phase
7
Q
T or F
Vector is usually a intermediate host
A
True
8
Q
What is the exception to the vector being an intermediate host rule
A
Plasmodium Infection
Anophele Mosquitos carrying plasmodium - malaria mosquito is the final or definitive host & humans = intermediate
9
Q
The animal that harbour a species of parasite & can serve as a source of parasitic infection is known as..
A
Reservoir Host
10
Q
What type of antibodies are formed when parasites elicit an immune response?
A
IgM, IgG, and IgA
11
Q
What are the factors effecting immune response to parasitic infections?
A
Rapid rate of reproduction
Large Size
Slime Layer & Capsule
Complex Life Cycles
Masking of surface antigens
Byproducts prevent production of antibodies, macrophages & lymphocytes
High production of IgE antibody (helminth worm)
Induced T-cell delayed hypersensitivity response
Concomitant - resistance to re-infection from an antibody
Long co-evolution with host = evolved adaptation
12
Q
What does concomitant mean?
A
Parasitic larval form can be distorted by host antibodies and the presence of antibodies provides resistance to re-infection by new larvae.
13
Q
T or F
A protozoa is a unicellular eukaryotic microorganism
A
True
14
Q
What is the name for the worm like organisms?
A
Helminths-metazoa
15
Q
Describe a protozoa
A
Unicellular, animal-like microbe usually having some form of motility
16
Q
What are the classifications of medically important protozoa
A
Style of movement
Mode of reproduction
Stages in the life cycle
17
Q
T or F
Most amebas are free living and very infectious
A
False
Usually not infectious
18
Q
T or F
Amebas are major loco motors with pseudopodia
A
True!
Some species have flagella during reproductive states
19
Q
How do Amebas reproduce?
A
Binary Fission (asexual)
20
Q
T or F
The cyst is the active form & the trophozoite is the inactive form
A
False!
Opposite is true
Cyst = inactive
Trophozoite = active
21
Q
Sarcodina aka
A
Ameba
22
Q
T or F
Flagellata reproduce both sexually and asexually
A
True
23
Q
What is the active form of a Flagellata? Inactive
A
Active = Trophozoite Inactive = Cyst
24
Q
All of the following are Flagellatas except: Trypanosoma Balantidium Coli Giardia Trichomonas Leishmania
A
Balantidium Coli
25
What is another name for Ciliophora?
Ciliata
26
What is the function of the cilia?
Movement
Attachment
Feeding
27
T or F
| Ciliata reproduce sexually
False!
Asexual Transverse Fission
28
Give an example of Ciliata discussed in class
Balantidium Coli
29
T or F
| The entire group of Sporozoa are parasites
True
30
How do Sporozoa reproduce?
By well developed asexual and sexual stages
31
Do most Sporozoa form Trophozoites or Cysts?
Cysts
32
What are the two main methods of transmission of Sporozoa?
Ingestion of the infective stage of protozoa
| By arthropod vector
33
Where are Sarcodina (ameba) most commonly found in the human body?
Lower GI tract
34
What stage of the life cycle of a Sarcodina is infective to humans?
Some form a non-feeding, non-motile cyst stage
35
What is the metabolizing stage of the Ameba?
Trophozoite
36
T or F
| In the active feeding stage of a Trophozoite they are sensitive to the environmental change
True
37
T or F
| The cyst form of Ameba cannot survive for periods outside the body
False!
Can!
38
What makes the cyst form of the Ameba resistant to environmental changes
It is surrounded by mineral wall, mostly calcium
39
How many nuclei can the cyst form have depending on species?
1-8
40
When can a cyst form a trophozoite from its nuclei? During what stage?
Excyst Stage
41
What conditions will stimulate excitation of a cyst in the Gi tract?
Alkaline pH
42
T or F
| Each nucleus of a cyst Ameba will produce 2 trophozoites
False!
| One for One
43
How does the Trophozoite become a cyst as it moves along the GI
Trophozoite moves along with a bowel movement, the environment becomes drier and the trophozoites start to undergo encystation
44
T or F
| Cyst formation can survive active dysentery
False!
| Cannot because the feces are so rapidly flushed from body.
45
What does Entamoeba Histolytica cause in humans?
Amebic dysentery
46
Describe the different forms of Entamoeba Histolytica
Large motile trophozoite
| Small non-motile cyst that contains 4 nuclei
47
What form of the Entamoeba will be destroyed in the mouth?
Trophozoite
| Cysts will not be destroyed
48
Where do the trophozoites attach themselves in the human body?
The mucous of cecum and large intestines with pseudopods. They will mature and reproduce here.
49
T or F
| 90% of patient infection is asymptomatic
True
50
Why are most patient infections of Histolytica asymptomatic?
Trophozoites do not invade beyond the most superficial layer of the mucous of cecum.
51
Severity of infection of Histolytica are related to?
Virulence of parasite
Inoculation size
Normal flora
Host resistance
52
The enzymes secreted by amebas in the intestinal tract leave small ulcerations that are what shape?
Flask
53
What are some life threatening complications associated with intestinal amibiasis?
Hemorrhage
Appendicitis
Tumor-like growth (amebomas)
54
What are the preventions and controls for Ameba infections?
```
Improve environmental and food sanitation
Water tx
Cholorination
Boiling
Iodine
Filtration
```
55
T or F
| Naeglaraia Fowleri is a free living ameba
True
56
Where is Naeglaria Fowleri usually found?
among water fowls, ducks, geese, and swans
57
What does Naeglaria Fowleri cause in humans?
Primary acute meningoencephalitis
58
What shape is the trophozoite of Naegleria?
Small and flask shaped and moves by a single broad psuedopod
59
Where does the Naegleria infection begin, and how?
Through the nasal passage of trophozoites as a result of swimming or diving in standing fresh water, lakes, ponds and even swimming pools and hot tubs.
60
What is another name for the Stigophorans
Flagellates
61
What is the reservoir for Trichomonas Vaginalis?
Human urogenital tract
62
What is the std caused by Trichomonas Vaginalis
Trichomonoiasis
Trichomanad vaginitis in females
Uretheritis in males
63
T or F
| Males have more symptoms that females for Trichomonoiasis
False
Females - creamy odorous green to yellowish vaginal discharge, vulvitis, cervicitis, and urinary frequency with pain.
64
If an asymptomatic male has Trichomonoiasis for years it can lead to what condition?
Procticitis
65
Describe the trophozoite of Trichomonas Vaginalis
Motile, pear shaped that can be identified in fresh urine or in a urethral or vaginal smear.
66
What is the most common intestinal flagellate parasite isolated in clinical specimens in the USA and most common type of parasite that pollute drinking water?
Giardia Lamblia
67
What does Giardia cause?
Travellers Diarrhea and Giardiasis
68
Describe what will happen to the ingested cyst of Giardia?
Excyst in the duodenum after 24 hrs
| Trophozoides will travel to the jejune where they feed and multiply
69
What is particular about the diarrhea associated with Giardia?
Foul smell
70
T or F
| Giardia is asymptomatic in 10% of infected individual due to the state of immunity
False
30%
71
T or F
| Cysts can be identified in stool specimens of Giardia
False
Trophozoites
72
What is the shape of the Giardia Trophozoite?
- Symmetrical heart shape with organelles positioned to resemble a face.
- 2 nuclei & 4 pairs of flagella
73
What kind of parasite is Leishmania and Trypanosoma?
Hemo-flagellate
74
How are Leishmania and Trypanosoma spread?
Blood sucking vectors
75
T or F
| Both Leishmania and Trypanosoma are free living flagellates
False
Obligate parasite that causes zoonatic disease
76
How is Leishmania transmitted and what disease does it cause?
Phlebotomine - Sand Fly
| Leishmaniasis
77
How many different pathogenic species of Leishmania are there?
4 that indistinguishable in appearance - but there is a different vector for each that is restricted to different geographic area.
78
What type of Leishmania occurs in certain mediterranean, African and Indian regions?
Tropica
79
In the life cycle of Leishmaniasis vector the amastigote forms and multiplies where in the human body?
Machrophages
80
What is the infective stage of Leishmaniasis and the method of infection?
- When the promastigote form multiplies in the gut of the fly.
- Vector will then bite human and regurgitates promastigote which will invade the tissue at the wound site.
81
What is the nature of infection of Leishmaniasis? Localized or systemic?
Both!
If macrophage remains fixed = localized
If macrophage migrate = systemic
82
What is another name for Cutaneous Leishmaniasis?
Oriental sore or Baghdad boil
83
What type of Leishmania causes red itchy lesions that can spread along the lymphatic. It is also self healing.
Braziliensis
84
What develops in a case of an absence of cell mediated immunity and Leishmania?
Diffuse Cutaneous Leishmonia
85
What Leishmania is characteristics of a long incubation period 2-18 weeks and a short term pimple at the bite site
Leishmania Donovani
86
Describe the symptomology of disseminated leishmonia donovani.
Splenomegaly
Hepatomegaly
Hyperplasia of tissue and organs
Progressive anemia
87
The trophozoite form of all leishmania is called?
Amastigote
88
What is the name of the flagellate form of leishmania?
Promastigote
89
What form is injected by an insect for Leishmania?
Promastigote
90
T or F
| The amastigote form of leishmania is extracellular
False!
| It is the intracellular parasite
91
T or F
| The promastigote form of Leishmania reproduces by binary fission.
True
92
Kala-azar is caused by?
Leishmania Donovani
93
What is a distinguishing characteristic of Trypanosoma?
Their infective stage - the Trypomastigote, an elongated, spindle shaped cell with tapered ends and single flagellum.
94
What are the two types of Trypanosoma and how do we distinguish them?
On a geographic basis:
1. Cruzi
2. Brucei
95
What type of lifecycle do the Trypanosoma live?
Biphasic life cycle between a warm blooded mammal and an insect.
96
What is the agent of Chaga's disease?
Trypanosoma Cruzi
| *in central and south america it is known as American Trypanosomiasis
97
What is the vector for Trypanosoma Cruzi?
The reduviid bug aka Kissing bug, Assasin Bug
98
Where does the trophozoite of the T.Cruzi multiply?
In the bugs intestinal tract and the bug feces contain the parasite.
99
How do humans get infected by the Assasin bug?
At night the bug usually bites the mucous membrane of peripheral area of lips, nose and eyes. As it fills with blood, the bug fills the bite with feces containing Trypanosoma.
100
T or F
| T.Cruzi cannot cross the placenta and cause prenatal disease
True
101
Name the two different forms of T.Brucei
1. T. Rhodiense - East African Sleeping Sickness
| 2. T. Gambiense - West African sleeping Sickness
102
What form of T.Brucei has a vector that is adapted to woodland and lakefronts?
Rhodiense
103
Where does the vector for T.Brucei Gambiense inhabit
Dense vegetation along rivers and forests.
104
What is the vector for T.Brucei
Tseste Fly - bite is very painful
105
Once the trypomastigote is ingested by tsetse fly what happens?
Changes form in an EPIMASTIGOTE which multiply in the fly gut.
106
What is a Chagoma Reaction?
Swelling that forces the eye shut and can be either unilateral or bilateral. This is the result of a bite from an insect containing Trypanosoma
107
Describe an Amastigote
A small, ovoid, non flagellated form of flagellate.
108
What is an Epimastigote?
A flattened, spindle-shaped, flagellated form seen primarily in the gut or salivary gland of the vectors in the life cycle of trypanosomes. Has an undulating membrane that extends from the flagellum.
109
What is the difference between the Epimastigote and the Promastigote?
The promastigote does not have the undulating membrane.
110
What are some symptoms of T.Rhodesiense?
Lesion of bite site = chancre (usually in non africans)
Enlarged lymph nodes, especially post. cervical chain = Winterbottom's Sign
Fever, headache, night sweats, nausea
Joint and muscle pain
111
Name the characteristics of Sporozoa
Obligate intracellular parasites
No apparent organelles of locomotion
Sexual and asexual reproduction
Generally involves 2 different hosts.
112
What type of reproduction for the Sporozoa uses the term Sporogony?
Sexual
113
What is the final organism formed from sexual reproduction of Sporozoa?
Sporozoites
114
What are the terms used to describe Asexual reproduction for Sporozoa
Schizogony -> Schizonts & Merozoites
115
What is the difference between Schizonts and Merozoites
```
Schizonts = offspring when asexual.r occurs in a somatic cell such as the paranychamal cells of the liver
Merozoites = offspring when asexual.r occurs specifically in RBC's
```
116
What does Schizogony mean?
Splitting
| - refers to binary fission type reproduction
117
How many sporocysts are in a mature oocyst?
2
118
How many sporozoites are in each sporocyst?
4
119
When an oocyst ruptures how many sporozoites are released?
8
120
The Sporozoa Taxoplama causes what condition?
Taxoplasmosis
