Brainscape's Knowledge GenomeTM

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


See full index

VMCB121 (3rd LE) > Microbial Infectivity, Pathogenicity, and Virulence > Flashcards

Microbial Infectivity, Pathogenicity, and Virulence Flashcards

1
Q

Microbial entry can be used in two senses:

A
  1. Ingress of microorganisms into body cavities
  2. Penetration of microorganisms into deeper tissue after crossing the epithelial barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

It involves entry without crossing epithelial barriers.

A

Ingress of microorganisms into body cavities

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

It involves microbes staying only on mucosal surfaces.

A

Ingress of microorganisms into body cavities

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

It involves microbes passing through epithelia (single cell layers)

A

Penetration of microorganisms into deeper tissue after crossing the epithelial barrier.

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

This is done with the help of insect bites, and cut surfaces.

A

Penetration of microorganisms into deeper tissue after crossing the epithelial barrier.

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

The penetration of microorganisms into deeper tissue after crossing the epithelial barrier is done with the help of?

A
  • insect bites
  • cut surfaces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Penetration of microorganisms into deeper tissue after
crossing the epithelial barrier is enabled by what?

A

receptors on the host cells

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

It involved being enabled by receptors on the host cells.

A

Penetration of microorganisms into deeper tissue after
crossing the epithelial barrier

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

What can burrow through the skin?

A

Parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do viruses bind to cell surfaces? by?

A
  • attachment
  • internalization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where do viruses bind into?

A

cell surfaces

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

Damage from microbial infection is often the result of?

A

immune response

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

Bacteria can also cause direct damage by producing what?

A

toxins

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

Bacteria can also cause direct damage by producing toxins which cause:

A
  1. Helps bacteria to spread in tissues.
  2. Lysis of host cells
  3. Stops cell growth
  4. Exaggerate normal physiological conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Bacterial toxin of Clostridium botulinum.

A

Botulinum toxin

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

Bacterial toxin of Clostridium tetani

A

Tetanospasmin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Bacterial toxin of Corynebacterium diphtheriae.

A

Diphtheria toxin

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

Bacterial toxin of Escherichia coli

A

Heat-labile toxin

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

Bacterial toxin of Vibrio cholerae

A

Cholera toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gene location of Clostridium botulinum

A

Bacteriophage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Gene location of Clostridium tetani

A

Plasmid

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

Gene location of Corynebacterium diphtheriae

A

Bacteriophage

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

Gene location of Escherichia coli

A

Plasmid

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

Gene location of Vibrio cholerae

A

Chromosome

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

Type of the toxin of Clostridium botulinum

A

Neurotoxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Type of the toxin of Clostridium tetani

A

Neurotoxin

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

Type of the toxin of Corynebacterium diphtheriae

A

A-B ADP ribosylating

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

Type of the toxin of Escherichia coli

A

A-B ADP ribosylating

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

Type of the toxin of Vibrio cholerae

A

A-B ADP ribosylating

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

Anti-colonizing properties of the Host

A
  • Sweep microbes away by liquid currents
  • Kill microbes with host phagocytes
  • Starve microbes for lack of needed nutrients
  • Inhibit growth by secreting antimicrobial factors such as cationic peptides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What do bacteria do to overcome the host sweeping the microbes away by liquid currents.

A

Adhere to epithelial cells

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

What do bacteria do to overcome being killed with host phagocytes?

A
  • Avoid being taken up
  • Kill the phagocyte
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What do bacteria do to overcome being starved of needed nutrients?

A

Derive needed nutrients from host cells

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

What do bacteria do to overcome having its growth inhibited by the host’s antimicrobial factors? (i.e. cationic peptides)

A

Modify surface molecules (lipid A) to avoid cationic peptide binding

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

Example of bacteria overcoming being swept away by the host’s liquid currents.

A
  • Gonococci (they stick to the mucous membrane of the urethra)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What do gonococci do to avoid being swept away by the host’s liquid currents?

A

Gonococci stick to the mucous membrane of urethra

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

Example of bacteria that avoid being killed by the host phagocytes by avoiding to be taken up.

A

Pneumococcus (It’s surrounded by a slimy capsule that impairs uptake by neutrophils)

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

Example of bacteria that avoid being killed by the host phagocytes by killing it instead 🤪🔪

A

Certain streptococci (produce a toxin that punches holes in the neutrophil membrane).

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

What do pneumococci do to avoid being taken up by the host phagocytes?

A

They avoid being taken up using the slimy capsule surrounding them, impairing the uptake of neutrophils.

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

How to certain streptococci manages to kill the host phagocytes that initially aims to kill them instead?

A

They produce a toxin that punches holes in the neutrophil membrane.

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

Example of bacteria that overcome being starved for their needed nutrients.

A

Certain staphylococci (lyse red blood cells and use their nutrients hemoglobin as a source of iron)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Structural, Metabolic and other features of bacteria which promote disease development.

A
  • Presence of capsule
  • Intracellular replication
  • Presence of high lipid content and mycolic acid in cell wall
  • Exotoxin production
  • Endotoxin production
  • Tropism for specific tissue
  • Localization and replication in sites with limited immunological responses
  • Synergistic bacterial interaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

An example of bacteria with a bacterial characteristic of presence of capsule.

A

Bacillus anthracis

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

An example of bacteria with a bacterial characteristic of Intracellular replication

A

Brucella abortus

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

An example of bacteria with the presence of high lipid content and mycolic acid in cell wall.

A

Mycobacterium bovis

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

An example of bacteria with a bacterial characteristic of exotoxin production.

A

Clostridium tetani

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

An example of bacteria with a bacterial characteristic of endotoxin production.

A

Escherichia coli

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

An example of bacteria with a bacterial characteristic of Tropism for specific tissue.

A

Moraxella bovis

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

An example of bacteria with a bacterial characteristic of Localization and replication in sites with limited immunological responses.

A

Leptospira interrogans serovars

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

An example of bacteria with a bacterial characteristic of Synergistic bacterial interaction

A
  • Fusobacterium necrophorum
  • Arcanobacterium pyogenes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

This bacterial characteristic can resist phagocytosis and multiply uninhibited in tissues.

A

Presence of capsule

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

This bacterial characteristic have the ability to survive within macrophages, making it an important virulence feature of brucellae.

A

Intracellular replication

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

This bacterial characteristic imparts resistance to environmental factors, detergents and disinfectants, and renders mycobacteria resistant to intracellular killing by macrophages.

A

Presence of high lipid content and mycolic acid in cell wall.

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

This bacterial characteristic involves the production of a potent neurotoxin, tetanospasmin that is responsible for the clinical signs of tetanus.

A

Exotoxin production

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

It acts as a pyrogen causing fever

A

Endotoxin

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

It causes intravascular coagulation and hypotensive shock.

A

Endotoxin

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

A bacterial characteristic with an endotoxin acting as a pyrogen causing fever as well as causing intravascular coagulation and hypotensive shock.

A

Endotoxin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Bacterial characteristic that involves attachment to the conjunctiva of cattle leads to keratoconjunctivitis,

A

Tropism for specific tissue

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

Bacterial characteristic of spirochaetes localizing in the renal tubules and are shed in the urine of infected animals

A

Localization and replication in sites with limited immunological responses

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

An example of this is in ruminant foot lesions, Arcanobacterium pyogenes produces a growth factor for Fusobacterium necrophorum. And the production of Fusobacterium necrophorum facilitates survival of A. pyogenes at the site of infection.

A

Synergistic bacterial interaction

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

In ruminant fool lesions, _____ produces a growth factor for _____

A
  • Arcanobacterium pyogenes
  • Fusobacterium necrophorum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Leukotoxin production by ____ facilitates the survival of ____ at the site of infection.

A
  • Fusobacterium necrophorum
  • Arcanobactrium pyogenes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What does Fusobacterium necrophorum produces that facilitates the survival of Arcanobacterium pyogenes at the site of infection?

A

Leukotoxin

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

The number of microorganisms present in a patient must exceed a given ____ to cause disease.

A

threshold

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

The number of microorganisms present in a patient must exceed a given threshold to cause what?

A

disease

66
Q

If the number of microorganisms is below that threshold, _____?

A

no signs and symptoms of disease will be apparent.

67
Q

In some cases of microbial multiplication and clinical manifestations of disease, the numbers oscillate above and below the threshold, resulting in?

A

recurrent bouts of disease

68
Q

The threshold of overt disease is not fixed by varies with?

A

with the physiological state of the host.

69
Q

Variety of ways cell death comes in:

A
  1. Direct action of cytolytic toxins
  2. Activation of cell-killing white blood cells
  3. Induction of programmed cell death
70
Q

It is prominent in acute infections, however, some agents allow infected cells to survive to ensure their own survival.

A

Cell death

71
Q

An example of bacteria that allow infected cells to survive to ensure their own survival.

A

Mycobacterium tuberculosis

72
Q

It refers to immune mechanisms that are always present and available for action.

A

Innate immunity

73
Q

2 Types of Microbial Immunity

A
  1. Innate Immunity
  2. Adaptive Immunity
74
Q

They are usually classified as humoral or cellular.

A

Adaptive immune responses

75
Q

Adaptive immune responses are usually classified as?

A
  • humoral
  • cellular
76
Q

It leads to production of circulating antibodies such as Immunoglobulins (IgA, IgG, IgM) and Complement System (serum proteins)

A

Humoral immunity

77
Q

Circulating antibodies examples of Humoral immunity

A
  • Immunoglobulins (IgA, IgG, IgM)
  • Complement System (serum proteins)
78
Q

Examples of Immunoglobulin

A
  • IgG
  • IgM
  • IgA
79
Q

Examples of Complement system as circulating antibody

A

serum proteins

80
Q

It causes production of immune system cells that destroy infected cells.

A

Cellular immunity

81
Q

It is associated with chronic inflammation.

A

Cellular Immunity

82
Q

Such responses can cause damage to the host cell.

A
  • Innate Immunity
  • Adaptive Immunity
83
Q

The balance between positive factors that promote health, and negative factors that predispose to disease can determine the what?

A

the health and welfare status of animal populations

84
Q

Stages of Infectious Disease

A
  1. Encounter
  2. Colonization
  3. Spread / Penetration
  4. Damage
  5. Resolution
85
Q

2 types of encounter of infectious disease

A
  1. Endogenous
  2. Exogenous
86
Q

Major routes of transmission of Infectious Disease

A
  • Direct contact
  • Inhalation/ Droplet infection
  • Ingestion/ fecal-oral route
  • Inoculation/ trauma
  • Transplacental
87
Q

Conditions for infectious disease colonization

A
  • Temperature and pH
  • Inactivation of IgA (IgA protease)
  • Production of adhesins, mucolytic enzymes.
88
Q

Types of spreading of infectious disease

A
  1. Direct extension
  2. Destroying cells
  3. Self-propulsion
89
Q

Direct extension of infectious disease spread can be found where?

A
  • Along tissue planes
  • Veins
  • Lymphatic vessels
90
Q

Mechanisms of damage of Infectious Disease

A
  • Bulk effect
  • Toxin mediated
  • Altered function of host systems
  • Host response to infection
91
Q

Resolution of Infectious Disease

A
  • Host response
  • Treatment
92
Q

What should a cell wall contain to impart resistance to environmental factors, detergents and disinfectants, rendering mycobacteria resistant to intracellular killing by macrophages?

A

Mycolic acid

93
Q

Attachment to the conjunctiva of cattle leads to what?

A

Keratoconjunctivitis

94
Q

The ability of a microbe to damage a host.

A

Pathogenicity

95
Q

This is caused by a pathogen or organism known as “virulence”

A

Degree of pathogenicity/ Damage

96
Q

Pathogen or organism that causes damage / degree of pathogenicity

A

Virulence

97
Q

These are traits that confer pathogenicity.

A

Virulence Factors

98
Q

Virulence factors include:

A
  • Adhesins
  • Toxins
  • Capsules
99
Q

In bacteria, they are only expressed when they are required.

A

Genes

100
Q

It allows the bacteria to attach to the host cell membrane, resisting flushing action of body fluids.

A

Adhesins

101
Q

2 General Types of Toxins

A
  1. Exotoxins
  2. Endotoxins
102
Q

These are proteins produced inside pathogenic bacteria, most commonly gram-positive bacteria, as part of their growth and metabolism.

A

Exotoxins

103
Q

These are secreted or released into the surrounding medium following lysis.

A

Exotoxins

104
Q

These are lipid portions of lipopolysaccharides (LPSs) that are part of the outer membrane of the cell wall of gram-negative bacteria.

A

Endotoxins

105
Q

They are liberated when the bacteria die and the cell wall breaks apart.

A

Endotoxins

106
Q

Where do microbes stay after their ingress straight into the body cavities?

A

mucosal surfaces

107
Q

They may be classified as exotoxin and endotoxin

A

Toxins

108
Q

Bacterial source of exotoxin

A

Mostly from gram-positive bacteria

109
Q

Bacterial source of Endotoxin

A

Gram-negative bacteria

110
Q

Its relation to microorganism is that it’s a metabolic product of growing cell.

A

Exotoxin

111
Q

The toxin is present in LPS in outer membrane of cell wall and released with destruction of cell or during cell division.

A

Endotoxin

112
Q

Its chemistry include proteins, that are usually with two parts (A-B)

A

Exotoxin

113
Q

Chemistry of Endotoxin?

A

Lipid portion (lipid A) of LPS of outer membrane

114
Q

It is specific for a particular cell structure or function in the host.

A

Exotoxin

115
Q

It is has a general effect on body, such as fever, weaknesses, aches, and shock; They all produce the same effects.

A

Endotoxin

116
Q

Its heat stability is unstable and can usually be destroyed at 60-80 degrees Celsius (except staphylococcal enterotoxin)

A

Exotoxin

117
Q

It is stable with heat and can withstand autoclaving (121 degrees Celsius for 1 hour)

A

Endotoxin

118
Q

Its toxicity is high

A

Exotoxin

119
Q

Its toxicity is low

A

Endotoxin

120
Q

It is not fever-producing

A

Exotoxin

121
Q

It is fever-producing.

A

Endotoxin

122
Q

It can be converted to toxoids to immunize against toxin ; neutralized by antitoxin.

A

Exotoxin

123
Q

It is not easily neutralized by antitoxin; therefore, effective toxoids cannot be made to immunize against toxin.

A

Endotoxin

124
Q

Its lethal dose is small

A

Exotoxin

125
Q

Its lethal dose is considerably large

A

Endotoxin

126
Q

Its representative diseases are
- Gas gangrene
- Tetanus
- Botulism
- Diphtheria
- Scarlet Fever

A

Exotoxin

127
Q

Its representative diseases are:
- Typhoid fever
- Urinary tract infections
- Meningococcal meningitis

A

Endotoxin

128
Q

It ingests a gram-negative bacterium.

A

Macrophage

129
Q

The bacterium is degraded in a what, releasing endotoxins that induce macrophage to produce cytokines IL-1 and TNF-α

A

Vacuole

130
Q

The cytokines are released into the bloodstream by the macrophages, through which they travel to?

A

the hypothalamus of the brain

131
Q

The cytokines induce the hypothalamus to produce ____, which reset the body’s thermostat to a higher temperature, producing fever.

A

prostaglandins

132
Q

What happens when the cytokines induce the hypothalamus to produce prostaglandins?

A

Reset the body’s “thermostat” to a higher temperature, producing fever

133
Q

What does the capsule interfere with to inhibit phagocytic engulfment? (to bind to complement and antibodies)

A

Opsonization

134
Q

It is found on the capsule to bind to IgG to act as “immune disguise” to inhibit phagocytic engulfment.

A

Protein A

135
Q

To inhibit phagocytic engulfment, Protein A found on the capsule binds to IgG antibody to act as?

A

“immune disguise”

136
Q

Genes involved in disease often appear as?

A

groups

137
Q

The term for when genes involved in disease appear as groups.

A

Pathogenicity Islands

138
Q

It can be a source of genes encoding virulence.

A

Bacteriophages

139
Q

The ____ are chromosomal and can also be in plasmids

A

Pathogenicity islands

140
Q

They can integrate genes into microbial chromosomes.

A

Bacteriophages

141
Q

Importance of Studying Virulence Factors

A
  • The use of genomic techniques has led to the identification of new virulence factors.
  • Understanding pathogenesis
  • Prevalence in clinical bacterial isolates
  • Knowledge about virulence factors may serve as targets for new therapies.
142
Q

Identification of _____ is necessary for diagnosis of infectious diseases.

A

Etiological agent

143
Q

Accuracy and validity of a laboratory examination is highly dependent on:

A
  • Specimen selection
  • Specimen collection
  • Specimen transport
  • Submission of samples
144
Q

Samples should be taken from a patient before what?

A

antimicrobial therapy

145
Q

It should be avoided or minimized.

A

Contamination

146
Q

It may be required in the laboratory diagnosis of bacterial infection.

A

Transport media

147
Q

Examples of Transport media.

A
  • Amie’s transport media
  • Stuart’s transport media
148
Q

_____ of samples may be required in laboratory diagnosis of bacterial infection.

A

Refrigeration

149
Q

In laboratory diagnosis of bacterial infection, samples should be:

A
  1. in leak-proof containers
  2. labelled properly
  3. transported with secondary/ tertiary packaging
150
Q

It contains charcoal that prolongs the viability of microorganisms.

A

Amie’s transport media for swabs.

151
Q

Laboratory Diagnosis being done for bacterial infection:

A
  1. Examination of stained smears
  2. Cultural and biochemical characteristics
  3. Biochemical techniques
  4. Serology
  5. Next generation sequencing (NGS)
  6. MALDI-TOF
152
Q

It is done using blood agar and MacConkey agar plates (24-48 incubation at 37 deg Celsius)

A

Routine isolation

153
Q

Examples of Biochemical techniques

A
  • Catalase
  • Oxidase test
154
Q

It is based on nucleic acid detection.

A

Molecular techniques

155
Q

It is the collection of two serum samples, 2 weeks apart.

A

Serology

156
Q

The four-fold rise in _____ demonstrates recent infection in Serology.

A

Antibody titer

157
Q

It can sequence the DNA of bacteria (millions of DNA simultaneously)

A

Next generation sequencing (NGS)

158
Q

What does MALDI-TOF stands for?

A

Maltrix-Assisted Laser Desorption/Ionization Time-of-Flight

159
Q

It is a technique that uses a laser to measure the mass of molecules in a sample

A

Mass Spectrometry

160
Q

It can identify bacterial isolates using their mass.

A

Mass Spectrometry

VMCB121 (3rd LE) (5 decks)

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