Exam 2 Flashcards
Study (89 cards)
1
Q
Direct Lifecycle
A
Only one host, freeliving stages are possible
Ex: Cymothoa exigua (replace fish tongue)
2
Q
Indirect lifecycle
A
2 or more hosts
Ex: Alaria americana
3
Q
Playbook for Parasitism
A
- Physucal proximity to suitable host
- Gain “entry” to suitable host
- Replicate and/or develop
4
Q
The Guinea Worm name
A
Dracunulus medinensis
5
Q
D. medinensis lifecycle
A
- Human drinks unfiltered water containing copepods with L3 larvae
- Larvae released, copepods die. Larvae penetrate stomach/intestinal wall. mature and reproduce
- fertilized female worm migrates to surface of skin, causes a blister, and discharges larvae
- L1 larvae released into water from the emerging female worm
- L1 larvae consumed by a copepod
- Larvae undergoes two molts in the copepod and becomes a L3 larvae
6
Q
Eradication = Behavior change
A
thought humans were definative host therefore keep humans from drink bad water
7
Q
G worm case trend
A
lowered then sudenly raised in 2016
8
Q
Animal that also spread guinea-worm
A
Dog, during fish harvests
9
Q
How many populations of D. medinesis is responsible for canine + human cases in Chad
A
One. All infection are caused by a single species
10
Q
Routes of Transmission (6)
A
Fecal - Oral (trophic accident)
Trophic (predator - prey)
Direct penetration
Vector borne
Sexual transmission
Vertical Transmission
11
Q
Do parasites use only one transmission strategy
A
No, a single parasite may use different ones as it moves between hosts
12
Q
Vector Borne Parasites examples
A
- Filarial nematodes
- Leishmania spp.
- Trypanosomes
- Plasmodium spp.
- Babesia
13
Q
Vector competence
A
Ability of a particular vector to become infected with and/or transmit a pathogen
14
Q
Vector capacity
A
- Regular feeding on host
- Abundance
- Dispersal ability
15
Q
Sexual transmission
A
in the name.
Ex. Trichomonas vaginalis (flagellated protozoan)
16
Q
Vertical transmission
A
Parent to offspring, not common for parasites
Ex: Babesia bigemina
17
Q
Parasite fecundity
A
Common to have lots of progeny when chance of any single one surviving is low
18
Q
Tapeworm Proglottids sexual
A
- are hermaphrodites and each proglottid has testies and ovaries
19
Q
Tapeworm Proglottids anatomy, top to bottom
A
- Scolex
- Neck
- Strobila
- Immature
- mature
- Gravid
20
Q
Parasite fecundity - metazoans
A
hella fucking eggs on the daily
can live for decades. cumulative reproductive rate is still very high
21
Q
Parasite fecundity- trematode polyembryony
A
- development of a single embryo into numerous other (identical) embryos
(metazoans;multiple cell types)
22
Q
Parasite fecundity- trematode Miracidium
A
invades a snail, and develops into a sporocyst which undergoes asexual reproduction to produce many ceraciae.
23
Q
Protozoan parasites reproductive rate
A
high with both sexual and asexual reproduction
24
Q
Generalized Apicomplexan (protozoan) asexual and sexual reproduction life cycle
A
Sexual
1. Gametes
2. Zygote
Sporogony happens
Asexual
3. Sporozoites
Merogony
- Merozoites (repeat)
Gametogony
REPEAT
25
Factors influencing transmission success (7)
- coinfection (intra + inter-species competition)
- Sex of host
- Age of host
- Reproductive status of host
- Envir temp
- pH
- Salinity
26
R _o
Basic reproductive rate
27
How do parasite + host size compare
They roughly match
28
Parasite vs. free-living relative genome size
parasite has the smaller genome. Genomes are replaced by something provided by the host
29
Quorum sensing
parasite-produced signals
30
Parasite EXIT strategies (6)
1. Fecal, sometimes urine (Fecal - oral)
2. Dormant/cyst form (trophic)
3. Cell rupture (penetration)
4. Vector borne
5. Sexual transmission
6. Vertical transmission
31
Susceptible hosts
Parasites wins - susceptible host
32
Resistant hosts
Host wins - resistant host
33
First step in preventing infection
Barriers
- skin
- mucus + cilia
- acid in tummy
34
Innate immune response
- immediate
- requires no prior exposure to the pathogen
35
Adaptive immune response
- highly specific
- repeated exposure to be successful
- AI response takes 10-14 days after initial exposures
36
Acquired sterile immunity
if organism survives first infection, it will not be reinfected
37
Primary response
1. IgM, most abbundant
2. IgG later grows more
takes a while
38
Secondary response
1. IgM
2. IgG greatly increases
39
Primary infection: threshold of disease
symptoms of disease pass the line; illness
40
Secondary infection: threshold of disease
- below the line
- subclincal infection
41
Do mostly all organisms have defense mechanisms
yes to
single cell orgs, pro, euk
42
Bacterial host defense with viruses: detector vs effector
Detector: recognize viral DNA
Effector: destroy viral DNA
43
Bacterial host defense: Type I error and consequence
- False positive
- self-mediated self destruction
44
Bacterial host defense: Type II error and consequence
- False negative
- phage-mediated self destruction
45
Restriction - modification system
- recognition of DNA sequence commonly found in phage
46
Restriction - modification system: Methyltransferase
- recognizes this site in the E. coli genome and modifies it
47
Restriction - modification system: Endonuclease
- recognizes the sequence and cleaves any unmodified DNA at the restriction site
48
Euk. Innate Immunity: PAMP
Pathogen Associated Molecular Pattern
49
Euk. Innate Immunity: PRR
Pattern recognition receptor
50
Different types of PAMPs (7)
- DNA
- RNA
- Surface glycoproteins
- Surface lipoproteins
- Cell wall/membrane (peptidoglycan + lipopolysaccharide)
- GPI anchors
51
When a PRR binds a cognate PAMP...(Detector or Effector)
it transduces a signal to the cell that the infection has occurred
52
Euk. Innate Immunity: The cell (org) will then respond with...
newly transcribed EFFECTOR mechanisms to resist, evade, destroy, weaken the invading pathogen
53
Which organisms is the PRR-PAMP based innate immune response central to the infection
Invertebrates and plants
54
What is the vertebrate immune system made of
Many highly specialized cell types
55
Activated function of Neutrophil
Phagocytosis and activation of bacterial mechanisms
56
Activated function of eosinophils
killing of antibody-coated parasites
57
Activated function of basophil
promotion of allergic responses and augmentation of anti-parasitic immunity
58
Activated function of mast cell
release of granules containing histamine and active agents
59
Activated function of macrophages
- phagocytosis and activation of bactericidal mechanisms
- antigen presentation
60
Activated function of dendritic cells
- antigen uptake in peripheral sites
- antigen presentation
61
Which cells are innate immune leukocytes
neutrophil, eosinophil, basophil
62
Which cells are mainly myeloid cells
mast cells, macrophages, dendritic cells
63
B + T lymphocytes --- Adaptive immunity
- Antigen specific detection
- Immune memory
- Effector function
64
Key concept for Acquired immunity: Antigen
Portion of a molecule (usually protein) recognized by either antibody or T cell receptor that stimulates an adaptive immune response
65
Antibodies
The body's collection of "locks" for every conceivable key that nature could make
66
Humoral immunity
- initiated by antigen recognition by B cells
- Mediated by antibodies
- Most effective against extracellular pathogens or their toxic products
67
Cell-mediated immunity
- initiated by antigen recognition by T cells
- mediated by T cells and other downstream effectors (macrophages)
- Most effective against intracellular pathogens
68
Humoral immunity
quick steps
1. Microbe = Extracellular microbes
2. Responding lymphocytes = B lymphocyte
3. Effector mechanism = secreted antibodies
4. Transferred by = Serum (antibodies)
5. Functions = Block infection and eliminate extracellular microbes
69
Cell-mediated immunity quick steps
1. Microbe = intracellular microbe replicating within cell or phagocytosed microbes in macrophage
2. Presponding lymphocytes = Helper T lymphocyte or cytolytic T lymphocyte
3. Effector mechanism =
4. Transferred by = T lymphocytes
5. Functions = Activate macrophages to kill phagocytosed microbes or kill infected cells and eliminate reservoirs of infection
70
Where do B & T lymphocytes arise from
in the bone marrow from a commin precurser
71
How do T lymphocytes differentiate into mature T cells
they leave BM and migrate to thymus
72
Which (B or T) have antigen receptors
Both
73
Effector T cells: CD8+ T cells are ...
Cytotoxic T cells
74
Effector T cell: CD4+ T cells are ...
Helper T cells
(some differentiate into Reg T cells;inhibit inflammatory response)
75
First step in activation of lymphocytes
Recognition of specific antigen
in 2` lymphatics for CD4 T cells
76
After initial antigen recognition, T cells will ___ and progeny will ___ but with the same ____
proliferate
differentiate into effector T cells
antigen specificity
77
Primed CD4 T cells differentiate into carious types of ...
helper or regulatory fates based on cytokines
78
Cytokines
small secreted proteins that act as chemical signals at the heart of (antiparasitic) immune responses
79
Key inflammatory cytokines
TNF alpha
IL12
IFN gamma
80
Key anti-inflammatory cytokines
TNF beta
IL10
81
(crossover) CD8+ T cell recognizes antigen presented by ...
MHC class I (mast cells)
82
(crossover) CD4+ T cell recognizes antigen presented by
MHC class II (professional APCs)
83
MHC Class II: which cells
- Professional APCs and activated B cells
84
MHC Class II: primes which cells
naive CD4+ T cells
85
MHC Class II: Cytokine exposure helps to determine the fate of ...
The CD4+ T cell into Helper or T regs
86
Protease cascade that eventually leads to diverse effector functions:
- cell lysis
- Opsinization (facilitating phagocytosis)
- Promote inflammation
- Helps guide leukocyte chemotaxis to infection site
87
Opsinization
Enhance phagocytosis of Antibody- bound parasite via Fc receptor
88
MHC Class I: Infected cells will present...
antigens from the pathogen it is infected with
89
CD8+ activation requires
CD4+ T cell help
