Brainscape's Knowledge GenomeTM

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


See full index

I&I WC1 > From encounter to disease - Bacteriology I > Flashcards

From encounter to disease - Bacteriology I Flashcards

Contains the lectures from Willem and about pneumococcal infections

1
Q

What is a factor to determine if bacteria are primitive?

A

Organization the cell itself

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

What are two-component systems?

A

Systems that carry out signal transduction

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

What are the two proteins of the two-component regulatory system

A
  • Sensor kinase
  • Response regulator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of a sensor kinase?

A

Detects environmental signal and autophosphorylates

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

What is the function of a response regulator?

A

DNA-binding protein that regulates transcription

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

Describe the possibility of the dual function of response regulators

A

Response regulator can be activating and inhibitory of the RNA polymerase –> transcription activated/inhibited

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

How many two-component systems can be found in E.coli?

A

50

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

Examples of two-component systems in E.coli

A
  • Phosphate assimilation
  • Nitrogen metabolism
  • Osmotic pressure response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the osmotic component system in E.coli

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

What are two-component systems important for?

A

Monitoring and responding to changes in the bacterial environment

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

Can you see a Campylobacter under your microscope if they are active? Why/why not?

A

No, they are way too fast. You have to numb them.

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

What happens to the movement of bacteria if there is a absence/presence of attractants in their surroundings?

A

Absence: random movement
Presence: directed movement

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

Why two kinds of movement are there for flagellated bacteria?

A
  • Peritrichous
  • Polar movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does peritrichous movement work?

A
  • Bundled flagella (CCW rotation). —>
  • Flagella pushed apart (CW rotation) <—>
  • Flagella bundled (CCW rotation) <—
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which division is important to make in polar movement of flagellated bacteria?

A

If a bacterium has a reversible- or unidirectional flagella

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

Orientation of movement of bacteria with: one flagella

A

Can move their flagella clockwise or counter clockwise

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

How does polar movement for bacteria with reversible flagella work?

A
  • CCW rotation —>
  • CW rotation <—
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does polar movement for bacteria with unidirectional flagella work?

A
  • CW rotation —>
  • Cell stops, reorients
  • CW rotation upwards
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do they sense their surroundings?

A

Two component system used in chemotaxis

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

How is the two-component system used in chemotaxis? (3)

A
  • Sense temporal changes in attractants or repellents
  • Regulate flagellar rotation
  • Regulate activity of pre-existing proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Definition of taxis

A

Directed movement in response to chemical or physical gradients

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

Different kind of ‘taxes’ (5)

A
  • Chemotaxis - chemicals
  • Phototaxis - light
  • Aerotaxis - oxygen
  • Osmotaxis - ionic strength
  • Hydrotaxis - water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

True or false: “Bacteria can actively search for targets”

A

True. Chemotaxis

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

What are endospores?

A

Survival structures to endure unfavorable growth conditions

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

Why are endospores perfect for bacteria that don’t have a flagella?

A

This ensures a perfect way to be spread

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

How are endospores spread?

A

Ideal for dispersal via wind, water, or animal gut

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

In what kind of bacteria can you find endospores?

A

Present only in gram-positive bacteria, (e.g., Bacillus and Clostridium)

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

Describe the sporulation stages (7)

A
  • Normal division
  • Commitment to sporulation –> asymmetric division
  • Spore is formed in the bug
  • Forms all kind of covers and stuff to penetrate materials
  • Bacterial cell lyses
  • Free endospore
  • Germination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Name an example of a disease that can occur due to endospores

A

Antrax infection in the lungs

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

What does the endospore package contain?

A

DNA needed to form a new bacterium

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

Describe the maltose catabolism in E.coli

A

Protein needs to bind maltose to form a complex on the activator site, RNA polymerase can bind –> machinery to metabolize maltose

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

What is catabolite repression?

A

Global regulating system: controls use of carbon sources if more than one presents

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

Catabolite repression is also called the “glucose effect”. Why?

A

Because the synthesis of unrelated catabolic enzymes is repressed if glucose is present in growth medium

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

What is diauxic growth?

A

Two exponential growth phases if two energy sources are available

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

How does diauxic growth work?

A
  • Better energy source consumed first, growth stops
  • After lag, growth resumes with second energy source
36
Q

What controls transcription in catabolite repression? How?

A

Cyclic AMP receptor protein. CRP binds to DNA only if it has bound cyclic adenosine monophosphate

37
Q

How is the inactive repressor generated to make lactose?

A
  • CRP/cAMP binds to operator and blocks transcription
  • Lacl is transcribed and translated
  • Active repressor
  • Inducer binds to AR
38
Q

Catabolization of a certain sugar by a bacterial cell depends on… (2)

A
  • Presence of the metabolite
  • Metabolic status of the cell
39
Q

What can influence the presence of a metabolite?

A

Presence of other sugars

40
Q

What is quorum sensing?

A

Mechanism by which bacteria assess their population density

41
Q

What does quorum sensing ensure?

A

That a sufficient number of cells are present before initiating a response that, to be effective, requires a certain cell density

42
Q

Name an example of a virulence factor of ‘E.coli O157:H7 shiga toxin–producing strain’ involved in quorum sensing?

A

Produces AHL AI-3 that induces virulence genes

43
Q

What does AL-3 bind to and where?

A

Sensor molecules in plasma membrane.

44
Q

What is the result of AL-3 binding to sensor molecules in the plasma membrane? (3)

A

Activation of
- Motility
- Toxin secretion
- Production lesion-forming proteins

45
Q

Name an example of a virulence factor of S.Aureus involved in quorum sensing?

A

Secretes small peptides that damage host cells or alter host’s immune system

46
Q

What controls this secretion of small peptides in S.Aureus?

A

Autoinducing peptide (AIP)

47
Q

What are potential drugs preventing virulence gene expression?

A

Quorum-sensing disruptors

48
Q

What are stringent responses?

A

Stress response in reaction to amino acid starvation

49
Q

Name an example of a stringent response in E.coli?

A

Voiding E. coli in feces reduces nutrients –>initiates ppGpp synthesis –> arrested cell division

50
Q

Name an example of a stringent response

A

Lungs hypoxic and phosphate-limited

51
Q

Function of the TATA box

A

Stable binding on the promoter

52
Q

Name two global control systems

A
  • Heat-shock response
  • RpoS regulon
53
Q

What is the function of the heat-shock proteins?

A

Counteract damage of denatured proteins and help cell recover from temperature stress

54
Q

How are heat-shock proteins induced?

A

Induced by heat, exposure to ethanol or ultraviolet (UV) radiation

55
Q

What factor largely controls the heat-shock response?

A

Alternative sigma factor RpoH

56
Q

What factor largely controls the RpoS regulon?

A

Stationary phase sigma factor

57
Q

What kind of infections can be caused by Streptococcus bacteria?

A
  • Pneumonia
  • Meningitis
  • Otitis media
58
Q

What kind of bacterium is S. pneumonia?

A

Gram-positive, microaerophillic coccoid bacterium (diplococcus)

59
Q

Describe the lifecycle of S. Pneumonia (3)

A
  • Colonization of epithelium
  • Transmission/Shedding
  • Invasion
60
Q

Where does colonization of S. Pneumonia happen?

A

Nasal epithelium

61
Q

Describe the three options of invasion of S. Pneumonia

A
  • Aspiration (lungs)
  • Bacteraemia (brain)
  • Local spread (ear)
62
Q

How can the general epidemiological curve of incidence be described? (pneumococcal infections)

A

U-curve (infants and elderly)

63
Q

Which factor can really influence the epidemiological curve?

A

Co-infection

64
Q

Which factors play a role in the onset of a co-infection? (4)

A
  • Epithelial cell damage
  • Decreased mucociliary velocity
  • Reduced CCL2 expression
  • Reduced macrophage functionality
65
Q

How can you perform an etiological diagnosis of pneumococcal infections? (4)

A
  • Isolation from URT, blood, sputum, CSF
  • Culture and characterization
  • PCR/MALDI-TOF
  • Bile solubility test
66
Q

What is the transformation principle?

A

DNA crossed over from the virulent strain to the non-virulent strain

67
Q

Advantage of the pneumococcal capsule

A

Capsule protects bacterium in the bloodstream against the immune system –> resistance against phagocytosis

68
Q

Describe the biosynthesis of the polysaccharide capsule

A
  • Every sugar structure has repeating units
  • New sugar that has to be added (specific for sugar) is flipped outside and attached to peptidoglycan
69
Q

Techniques used to determine genetic variation amongst S. Pneumonia? (2)

A
  • Multi-locus sequence typing
  • Whole genome sequencing
70
Q

How can a non-competent cell become competent? How is competence induced?

A

Horizontal gene transfer induced by environmental signals (high cell density, stress)

71
Q

What does competence lead to?

A

Killing of neighboring cells

72
Q

Which proteins can be found in the pneumococcal cell wall? (4)

A
  • Phosphorylcholine binding proteins
  • Peptidoglycan binding proteins
  • Classical surface proteins
  • Lipoproteins
73
Q

What is the function of ABC transporters?

A

Niche adaptation

74
Q

What is essential for the induction of inflammation? What does this phenomenon lead to?

A

Pore formation. Leads to faster clearance and increased transmission

75
Q

Which additional factors influence transmission if you are a nasal carrier of S. pneumonia? (5)

A
  • Pneumolysin
  • Capsule type and amount
  • Anticapsule IgG
  • Anticapsule IgA1
  • Viral co-infections
76
Q

Function of pneumolysin in transmission of s.pneumonia? (2)

A
  • Increased shedding
  • Inflammation promotes secretions
77
Q

Capsule type amount

A
  • Increased shedding
  • Inhibition of mucin entrapment
78
Q

Anticapsule IgG

A
  • Decreased shedding
  • Agglutionation blocks release
79
Q

Anticapsule IgA1

A
  • No effect on shedding
  • Bacterial protease relieves agglutination
80
Q

Viral co-infection

A
  • Increased shedding
  • Increased bacterial load and mucus production
81
Q

Which factors influence the prominence of S. pneumonia as a cause of disease? (3)

A
  • High carriage rates
  • Genetic adaptability
  • Ability to shift from commensal to pathogenic interaction with host
82
Q

From colonisation to invasive disease requires niche adaptation. Name two ways of niche adaptation

A
  • Metabolic adaptation
  • Immunological adaptation
83
Q

What is meant with metabolic adaptation?

A

Maintenance of metal levels, different carbon sources

84
Q

What is meant with immunological adaptation?

A

From non-sterile to sterile site

85
Q
A

I&I WC1 (25 decks)

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