Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BHSC 3329 - Immunology > Unit 1 - Determinants of Pathogenicity > Flashcards

Unit 1 - Determinants of Pathogenicity Flashcards

1
Q

Define Pathogen

A

Organisms that cause disease in their host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are 4 examples of pathogens?

A
  1. Multicellular parasites
  2. Single celled parasites
  3. Bacteria
  4. Viruses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

True or False:

We rely on microbes to protect us everyday

A

True

- they create a biofilm on our skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define vertical transmission

A

Transmission of infectious disease from mother to embryo, fetus or baby during pregnancy or childbirth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define horizontal transmission

A

Transmission of infectious disease after birth or from another source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or False:

Transmission of infectious disease can be by direct contact or indirect

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a vehicle?

A

A NON-living medium that can spread disease (water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a vector?

A

A LIVING medium that can spread disease (mosquito)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False:
Vectors TEND to be indirect transmission
Vehicles TEND to be direct transmission

A

False

  • Vectors tend to be direct
  • Vehicles tend to be indirect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False:

Animal feces are vehicles, not vectors

A

True

  • this is b/c animal feces are not living things
  • they are an animal product
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True or False:

The uterus is always germ-free

A

False

- uterus is germ-free until birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What protects the uterus from vaginal microbes?

A

Fetal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When does a baby first come into contact with microbes?

A

During delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When does colonization (of microbes) of a baby occur?

A

Within 8 - 12 hours after birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What bacteria is contained within mother’s milk (when breastfeeding)?

A

Bifidobacterium (primarily)

- this bacteria has adapted along with us

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or False:

Bottle fed babies are exposed to more bacteria in bottled milk compared to breast fed babies in mother’s milk

A

True

  • bottle fed = coliforms, lactobacilli, enteric streptococci, staphylococci
  • breast fed = bifidobacterium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What percentage of microbes make up the human body?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define niche

A

A compartment with unique properties

temperature, pH, nutrients, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some examples of tissues that harbour resident microbes?

A
  • skin
  • upper respiratory tract
  • GI tract
  • vagina
  • Urethra (outer opening only)
  • External ear and canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are some example of tissues/organs that are germ-free?

A
  • Brain
  • Muscles
  • Blood
  • Lower respiratory tract
  • Kidneys and bladder
  • Bones
  • Ovaries/testes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is mutualism?

A

Two organisms cooperate to BOTH benefit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is commensalim?

A

One organism benefits WITHOUT harm to the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is parasitism?

A

One organism benefits WHILE harming the other (or at the expense of)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a reservoir?

A

The source of the disease/pathogen

- where the disease comes from or where the disease is hiding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why do we NOT want everything to be sterile?

A

Because if we get exposed to bacteria/pathogens

  • we won’t have “good” bacteria to protect us
  • not all microbes are bad
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What must pathogens do first before they can infect an individual?

A

Adhere

- attach to the host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

True or False:

Communal microbes have adapted to penetrate follicular canals on the skin

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

True or False:

After hand washing communal microbes will grow back

A

True

- because they have adapted to living in the follicular canals on the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What happens to communal microbes on the skin if you use anti-microbial soaps or alcohols?

A

They are all killed

- you then leave it up to chance with what you are colonized with next (whatever is in the environment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why is the epidermis part of the immune system?

A

Because it acts as a barrier

- skin is constantly falling off, and taking pathogens with it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where do transient (temporary) microbes reside?

A

Colonize on the epidermis (surface)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where do resident microbes reside (in relation to the skin)?

A

Penetrate into the deeper layers of the epidermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does it mean for microbes to be endogenous?

A

They are “within” the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does it mean for microbes to be exogenous?

A

They are “from an outside source”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do sight, respiration, digestions, glandular secretion, birth, and urination - all have in common?

A

All require temporary exposure of internal tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Despite the hostile condition of the GI tract, why is it commonly colonized with microbes?

A

It is RICH in nutrients!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Approximately how many species makes up the biofilm of the mouth?

A

More than 600 bacterial species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What percentage of fecal volume do microbes make up?

A

Approx 10 - 30% volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does information the coliform count tell us?

A

Indicator of unsanitary conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which bacteria in the large intestine provide vitamins to us?

A

E. coli

- they ferment waste and produce B12 and Thiamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

True or False:

The upper respiratory tract is germ-free

A

False

  • the upper resp is rich in microbes
  • the lower resp is germ-free
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the suspected function of the tonsils and the appendix?

A

Sites where microbes are cultured

- grown on purpose and released when necessary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Describe what microbial antagonism is

A

Resident microbes protect against other potentially harmful pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the female vagina usually inhabited with and why?

A

Lactobacillus
- when they eat the glycogen produced by the estrogen, it produces an acidic environment (pH 4.5) that prevents the growth of other microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What happens to the Lactobacillus in the female vagina if the patient takes a broad spectrum antibiotic?

A

Kills off good and bad bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

True or False:

Humans have been infected by retroviruses throughout our evolution

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is a distinctive feature of retroviruses?

A

Have the ability to integrate their DNA INTO the human (or other) genome
- virus DNA becomes part of the human genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What happens to retroviruses once they integrate into your genome?

A

They become attenuated (less pathogenic)

- b/c they don’t want to kill you, they want the host alive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What retrovirus makes up 8 - 10% of the human genome?

A

HERV

- human endogenous retrovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Define biofilm

A

Multiple species of microbes grow together and cooperate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Define microbial antagonism

A

Good bacteria impairing the colonization of pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are probiotics?

A

Commensal organisms believed to support human health

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What do broad-spectrum antibiotics do?

A

Kill off “good” and “bad” microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How do exogenous microbes enter the body?

A

Through portals of entry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Define infection

A

Invasion of microbes into germ-free tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the virulence factor?

A

A characteristic of a microbe that increases its capacity to cause HARM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the 7 steps of the infection process?

A
  1. Portal of entry
  2. Adhesion
  3. Invasion
  4. Multiplication
  5. Infection of target
  6. Disease
  7. Portal of exit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What does it mean if a pathogen has “infectivity” characteristics?

A

Capacity to invade and replicate in host tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

If a microbe is pathogenic, how could you describe its virulence?

A

A quantitative measure of the pathology that results from infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the infectious dose (ID)?

A

Minimum number of microbes to cause infection (morbidity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the lethal dose (LD)?

A

Minimum number of microbes to cause death (mortality)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

True or False:

A toxin can cause infection

A

False

- a toxin can be lethal, but they do not infect you

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Define prevalence

A

Number of people in a population that are infected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Define incidence

A

Number of new cases (new infections) in a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What does ID50 mean?

A

Minimum number of microbes to cause infection in 50% of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What does LD50 mean?

A

Minimum number of microbes to cause death in 50% of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

True or False:

A microbe with a HIGH LD is more deadly than a microbe with a LOW LD

A

False

  • a high LD means that you need a large number of the microbe in order to cause death
  • a low LD means that you need very few microbes in order to cause death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Where is E. coli typically found?

A

In the lower intestine of warm-blooded animals

- produces toxins that break down the gut lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Where is Vibrio Cholera found and what does it do?

A

Found in the small intestine of people and some aquatic habitats

  • produces cholera toxin: draws salts and water into the intestion
  • results in severe diarrhea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Should we be more concerned if a microbe has a HIGH ID50 and a HIGH LD50 … or a LOW ID50 and a LOW LD50?

A

LOW

- requires SMALL numbers in order to infect or kill

71
Q

What does it mean if a pathogen is a “true” pathogen?

A

They can cause disease in individuals with a NORMAL functioning immune system

72
Q

What does it mean if a pathogen is an “opportunistic” pathogen?

A

They only cause disease in immuno-compromised individuals

73
Q

True or False:

E. coli are typically high infectious but have a low-moderate virulence

A

True

  • ID50 = 10
  • low to moderate virulence depending on the strain
74
Q

True or False:

Vibrio cholera are typically highly infections and highly virulent

A

False

  • poorly infectious (ID50 = 10^6 - 10^11
  • but highly virulent!
75
Q

What are three things that a pathogen must do in order to be virulent?

A
  1. Adhesion
  2. Invade - invade germ-free tissues/organs
  3. Immune evasion - overcome the immune system
76
Q

What are some adapted measures that multicellular parasites have adapted to assist with adhesion (3)?

A
  1. Suckers
  2. Hooks
  3. Barbs
77
Q

The head of a tapeworm has a crown of hooks, followed by a row of suckers to adhere to host’s tissues. Is this a specific or non-specific adhesion method?

A

Non-specific

78
Q

True or False:

Tapeworms do not have their own digestive system

A

True

- they absorb nutrients from you!

79
Q

What can the falgellum be used for, and is it specific or non-specific?

A
  1. Motility
  2. Adherence
    - Non-specific
80
Q

What can fimbriae be used for, and are they specific or non-specific?

A
  1. Motility
  2. Adherence
    - Non-specific
81
Q

What is a slime layer used for and is it specific or non-specific?

A
  1. Adherence

- Non-specific

82
Q

Do gram (+) or gram (-) bacteria have a cell wall?

A

Gram (+)!

83
Q

What is the primary component of the cell wall of gram (+) bacteria?

A

Peptidoglycan

thick layer

84
Q

What is the main component on the outside of a gram (-) bacteria?

A

Lipopolysaccharide

- with a thin layer of peptidoglycan

85
Q

What is the name of the layer of polysaccharide that can be sticky or form a protective coat around a bacteria?

A

Capsule

- has a sticky, sugary coating (non-specific)

86
Q

What are the two main components of a virus?

A
  1. Capsid

2. Envelope

87
Q

What is the role of the capsid in a virus?

A

It is the inner core where genetic material is contained (DNA or RNA)

88
Q

What is the role of the envelope in a virus?

A

It is the outer membrane where specific virus proteins bind to very specific host proteins

89
Q

What is the name of the viral protein on the outside of HIV that binds to the surface of human cells?

A

GP120

90
Q

What is the relevance of HIV and influenza having RNA genome?

A

RNA mutates faster than DNA genomes

- easier for mutations to occur

91
Q

What three non-specific features do multicellular parasites use for adhesion?

A
  1. Hooks
  2. Suckers
  3. Barbs
92
Q

What three non-specific features do bacteria use for adhesion?

A
  1. Fimbriae
  2. Flagella
  3. Capsule
93
Q

What two specific features do viruses use for adhesion?

A
  1. Envelope

2. Capsid

94
Q

What are the three methods that pathogens can used to invade germ-free tissues?

A
  1. Exoenzymes
  2. Toxins
  3. Surviving endocytosis
95
Q

True or False:
The human respiratory and digestive systems are vulnerable to invasion because the tissues are thin and in close proximity to the bloodstream

A

True

96
Q

If fungi do not have a digestive system, how do they feed?

A

Secrete enzymes into the environment

- then absorb those nutrients

97
Q

What are exoenzymes?

A

Enzymes that are secreted out of the cell

98
Q

What is hyaluronidase?

A

A “spreading factor”

  • breaks apart the “cement” that is holding your cells together
  • your cells will fall apart from each other - resulting in open wounds
99
Q

What does the suffix “-ase” indicate?

A

An exoenzyme

100
Q

What does mucinase do?

A

Disrupts the protective mucous membranes

- an exoenzyme

101
Q

What does keratinase do?

A

Digests structural proteins of skin and hair

- an exoenzyme

102
Q

What does collagenase do?

A

Digests connective tissue

- an exoenzyme

103
Q

What does hyaluronidase do?

A

Digests hyaluronic acid (cement that holds cells together)

- an exoenzyme

104
Q

What does coagulase do?

A

Promotes blood clotting

- an exoenzyme

105
Q

Why would some fungi have adapted to forming blood clots around them using coagulase?

A

If the fungi are surrounded by blood clots, the immune system won’t be able to find them

106
Q

What kind of toxins are typically used in invasion?

A

Exotoxins

- used to kill any cells that are acting as a barrier

107
Q

What do E. coli produce that kill gut epithelia?

A

Shiga toxin (verotoxin)

108
Q

How have Salmonella enterica adapted to invade tissues?

A

Surviving Endocytosis

  1. Adhesion by fimbriae
  2. Secretion system (injects proteins into cells, reprogram them, tell them to eat Salmonella)
  3. Salmonella do not get eaten by lysosomes
  4. Multiply internally
  5. Released into bloodstream in large numbers
109
Q

What are 4 things that pathogens would have to evade in order to survive the immune system?

A
  1. Tissue barriers (physical barriers)
  2. Gastric juices (physiological barrier)
  3. Anti-phagocytic factors
  4. Leukocytes
110
Q

What is the name of the microbe that lives in the stomach of approx. 50% of people?

A

Helicobacter pylori (H. pylori)

111
Q

How have H. pylori adapted to living in the stomach of people (2)?

A
  1. Corkscrew motion of flagella drills the microbe through mucosal lining of the stomach
  2. Produces urease enzyme which degrades urea into ammonia … this neutralizes the stomach acid
112
Q

How can a microbe survive phagocytosis (2)?

A
  1. By creating a capsule to surround it

2. Hiding inside host cells

113
Q

What are leucocidins?

A

Toxins secreted by some microbes that specifically kill immune cells
- it is a protein

114
Q

What is the resulting effect of leucocidins?

A

Will immuno-compromised the host

115
Q

What are two examples of microbes that secrete leucocidins?

A
  1. M. tuberculosis

2. HIV

116
Q

What does the suffix “-in” tell you?

A

It is a PROTEIN!

117
Q

What are the two classes of toxins?

A
  1. Endotoxin

2. Exotoxin

118
Q

What kind of bacteria produces endotoxins?

A

Produced by gram (-) bacteria

- from degradation of lipopolysaccharide cell wall

119
Q

When are endotoxins fatal?

A

Only fatal in LARGE doses

- can induce fever that can lead to death

120
Q

What kind of bacteria produces exotoxins?

A

Produced by gram (-) OR gram (+) bacteria!

121
Q

True or False:

Exotoxins are proteins

A

True

122
Q

When are exotoxins fatal?

A

In SMALL doses

- can lead to tissue or organ failure

123
Q 
True or False:
A gram (+) bacteria can produce endotoxins and exotoxins
A

False!

- A gram (-) bacteria can produce endotoxins and/or exotoxins

124
Q

True or False:

If you heat up an endotoxin, it will degrade

A

False

  • Endotoxins are stable at high temperatures b/c they are lipids
  • therefore, still toxic when heated
125
Q

True of False:

Endotoxins cannot be converted to toxoids

A

True

- antibodies do not bind to lipids well - therefore there is NO ANTI-TOXIN

126
Q

What is the main clinical concern when dealing with endotoxins?

A

Managing the escalation of the inflammatory response

127
Q

What is a toxoid?

A

A modified toxin

  • it keeps its general shape, but it is not as harmful
  • we can make antibodies against them
128
Q

True or False:

Exotoxins denature at high temperatures

A

True

129
Q

True or False:

Anti-toxins cannot be produced for exotoxins

A

False

130
Q

True or False:

Exotoxins are the result of the degradation of the lipopolysaccharide cell wall

A

False

- Exotoxins are secreted from LIVE cells

131
Q

True or False:

Endotoxins can cause damage if the cells are alive or dead

A

True

- this is because the toxins are released from the degradation of the LPS

132
Q

What is an example of a Receptor Ligand Exotoxin?

A

AB toxin

  • Pertussis
  • Cholera
  • Shiga
133
Q

What are two domains of the AB toxin and what do they do?

A

A domain = an enzyme that disrupts the cell function

B domain = binds to a specific receptor on the target cell surface

134
Q

True or False:

AB toxins enter the target cell via endocytosis

A

True

135
Q

What happens to the AB toxin once it enters the target cell?

A

Lysosomes break up the AB linkages

  • A domain gets released into the body and causes harm
  • (acidification of vacuole dissociates th A enzyme)
136
Q

True or False:

Endotoxins can be deactivated and then injected into a host to make antibodies

A

False

- EXOTOXINS can be deactivated and then injected into a host to make antibodies

137
Q

What happens when a patient is injected with a toxoid?

A

Patient becomes immune to the toxin

- these are exotoxins

138
Q

What happens when a patient is injected with an anti-toxin?

A

Rapid relief to a NON-IMMUNE patient

  • immunity is NOT transferred
  • these are exotoxins
139
Q

What are two examples of exotoxins that affect the GI tract? What is their proper name and what do they do?

A

Enterotoxins
1. Shiga toxin = E. coli degrades the GI wall = blood diarrhea

  1. Choleragen (produced by Vibrio cholera) - stimulates water secretion into gut = rice-water stool
140
Q

What is the botulism toxin an example of and what does it do?

A

Botulism toxin = Neurotoxin

- causes flaccid paralysis (numbness)

141
Q

What is tetanus an example of and what does it do?

A

Tetanus = Neurotoxin

- causes spastic paralysis (constant muscle contraction)

142
Q

What is the name of the exotoxin that affects red blood cells? What does it do?

A

Hemolysins

  • S. pyogenes
  • breaks open RBCs
143
Q

What is the name of the exotoxin that affects white blood cells? What does it do?

A

Leucocidins

  • S. aureus (necrotizing pneumonia)
  • Targets WBCs and destroys them
144
Q

Which has a lower LD50, endotoxins or exotoxins?

A

Exotoxins

- you only need a small amount to kill someone

145
Q

True or False:

Exotoxins are proteins

A

True

146
Q

What are 4 types of exotoxins?

A
  1. Enterotoxin = GI
  2. Neurotoxin = neurons
  3. Hemolysin = RBCs
  4. Leucocydin = WBCs
147
Q

What is the role of hemoproteins in humans?

A

Helps iron dissolve by associating it with proteins called hemoproteins
- ferratin, transferrin, lactoferrin

148
Q

True or False:

Bacteria, fungi and other microbes have easy access to iron

A

False

  • they are often starved for iron
  • therefore, adapted proteins that bind iron at HIGH AFFINITY
149
Q

What is affinity?

A

The strength at which two molecules bind

150
Q

What are siderophores and what do they do?

A

High-affinity proteins that absorb heme and iron

- to be taken back into the cell

151
Q

What microbes secretes siderophores?

A

Bacteria

- TB, E. coli, Anthrax, Cholera, Black Plague

152
Q

What is the suffix that indicates a siderophore?

A

“-bactin”

153
Q

In the body, what are a rich source of iron?

A

RBCs

154
Q

What can microbes produce that disrupt RBCs in order to access their iron content?

A

Hemolysin

155
Q

What is one method of classifying Streptococcus species?

A

By their hemolysis patterns

156
Q

What is the important difference that a chocolate agar and a blood agar plate will tell you?

A
  1. If it grows on chocolate, it likes iron but cannot lyse RBCs
  2. If it grows on blood agar, it likes irons AND can lyse RBCs
157
Q

What does the alpha pattern tell you?

A

Partial lysis of RBCs

- ex: S. pneumoniae

158
Q

What does the beta pattern tell you?

A

Complete lysis of RBCs

- ex: S. pyogenes

159
Q

What does the gamma pattern tell you?

A

Non-hemolytic

- non-pathogenic commensals

160
Q

True or False:

Humans bind iron to siderophores while bacteria bind iron to hemoproteins

A

False

  • Humans bind iron to hemoproteins
  • Bacteria bind iron to siderophores
161
Q

True or False:

Mechanisms involved in evolution and adaptation are considered virulence factors for microbial populations

A

True

162
Q

The immune system uses what two key antigens to identify and develop immunity against influenza?

A
  1. Hemagglutinin (HA)

2. Neuraminidase (NA)

163
Q

What does the virus do if the immune system detects a specific HA antigen shape?

A

The virus mutates to change it’s shape

164
Q

What is “antigenic drift”?

A

Small changes/variations

  • DUE TO MUTATION
  • changes are small enough that it will cause symptoms but your immune system will recognize the virus
165
Q

What is “antigenic shift”?

A

Major changes

  • DUE TO GENETIC REASSORTMENT
  • so much so, that your immune system does not recognize it as the flu (example)
  • immune system does not formulate a response
166
Q

True or False:

Avian flus rarely infect humans. But avian and human influenza can infect pigs

A

True

167
Q

What happens TO THE VIRUS if a pig is infected with both avian and human influenza?

A

The virus reshuffles its RNA molecules

  • to form a virus that is dramatically different
  • we would not have immunity to it
168
Q

What is genetic reassortment?

A

When a virus reshuffles it’s RNA (or other genetic molecules)
- ex: avian and human flu in pigs = new flu virus

169
Q

What does antigenic drift usually cause?

A

A disease outbreak

- a disease that occurs at greater frequency

170
Q

What does antigenic shift usually cause?

A

A pandemic

- humans have no natural immunity and the disease quickly spreads throughout the world

171
Q

What is the african sleeping sickness caused by?

A

Protest parasite called a TRYPANOSOME

172
Q

Why is it so hard for the immune system to beat the african sleeping sickness?

A

It has VARIABLE surface glycoproteins

  • once the immune system develops resistance
  • the pathogen changes shape to evade the immune cells
173
Q

What is antigenic variation?

A

Changes in cell surface features to evade immune cells

BHSC 3329 - Immunology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions