Lecture 8 - Innate Immunity and Bacteria

Question 1

Pathogens detected by TLR 1/2 and 2/6

Answer 1

Bacteria, mycobacteria, fungi

Question 2

Which bacteria have LPS?

Answer 2

Gram -

Question 3

Which part of a bacterial cell wall gives resistance to many proteolytic enzymes?

Answer 3

D-isoform of amino acids

Question 4

Where is peptidoglycan in G- bacteria?

Answer 4

Periplasmic space

Question 5

Structure of peptidoglycan

Answer 5

1) N-acetylmuramic acid
2) N-acetylglucosamine
3) N-acetylmuramic acids linked by 4 amino acid oligopeptide chains

Question 6

What are the oligopeptides in peptidoglycan made up of?

Answer 6

D- and L- amino acids

Question 7

What does lysozyme degrade?

Answer 7

Polysaccharide bond between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycan

Question 8

Typical G+ genera

Answer 8

Streptococcus, staphylococcus, bacillus

Question 9

Thickness of peptidoglycan in G+ bacteria

Answer 9

20 - 80nm

Question 10

Acidic polysaccharides in G+ peptidoglycan
1)
2)

Answer 10

1) Teichoic acid - Polymer of ribitol or glycerol and phosphate
2) Lipoteichoic acid - teichoic acid linked to lipids in cell wall

Question 11

Typical Gram- genera

Answer 11

Salmonella, Escherichia

Question 12

Typical width of periplasmic space

Answer 12

20 - 70nm

Question 13

Composition of G- outer membrane
1)
2)
3)
4)

Answer 13

1) Protein (EG: porins)
2) Lipoprotein
3) Phospholipid
4) Lipopolysaccharide

Question 14

Proportion of G- outer membrane that is lipid

Answer 14

15%

Question 15

Part of LPS that is toxic

Answer 15

Lipid A

Question 16

Most conserved part of LPS

Answer 16

Lipid A

Question 17

Most variable part of LPS

Answer 17

O-specific polysaccharide

Question 18

Major parts of LPS
1)
2)
3)

Answer 18

1) Lipid A
2) Core polysaccharide
3) O-specific polysaccharide

Question 19

What determines whether LPS is smooth or rough?

Answer 19

Smooth - long chain O-specific polysaccharide

Rough - short chain O-specific polysaccharide

Question 20

Result of excess lipid A in the blood

Answer 20

Raised temperature

Fever - septic shock, endotoxic shock

Question 21

Molecule used to serogroup bacteria

Answer 21

O-specific polysaccharide

Question 22

TLR activated by cell wall components

Answer 22

TLR1, 2, 4, 6

Question 23

Examples of bacteria that stain Gram negative, but are Gram positive

Answer 23

Mycobacterium, Nocardia

Question 24

Bacterium that lacks a cell wall

Answer 24

Mycoplasma

Question 25

Composition of glycocalyx in bacteria

Answer 25

Usually polysaccharide

Can be polypeptide, or both

Question 26

Capsule glycocalyx structure

Answer 26

ORganised, repeating units attached to cell surface

Question 27

Slime layer glycocalyx structure

Answer 27

Loose, water-soluble structure

Question 28

Function of capsules and slime layers
1)
2)
3)
4)
5)

Answer 28

1) Prevent dessication
2) Prevent phagocytosis
3) Prevent opsonisation
4) Promote biofilm formation
5) Promote adhesion

Question 29

Which type of pathogenic bacteria often have glycocalyces?

Answer 29

Blood-borne pathogens

Question 30

How is a bioflim on the teeth formed?
1)
2)

Answer 30

1) Bacteria attach to salivary proteins on tooth surface

2) Provides anaerobic environment for bacteria to flourish

Question 31

Parts of a prokaryotic flagellum
1)
2)
3)

Answer 31

1) Filament
2) Hook
3) Basal body

Question 32

Type of bacteria with sialic acid-rich capsule

Answer 32

Neisseria meningitidis type B

Question 33

Prokaryotic movement patterns
1)
2)

Answer 33

1) Runs - Straight lines

2) Tumbles - Rapid, abrupt changes in direction

Question 34

What is H type?

Answer 34

Type of flagellum that a bacteria has

Question 35

Organisation of E. coli flagella

Answer 35

Multiple lateral flagella

Question 36

Organisation of Vibrio flagella

Answer 36

Single polar flagellum

Question 37

Organisation of T. pallidum flagella

Answer 37

Periplasmic flagella

Flagella are located in periplasmic space, ‘vibrate’ bacteria

Question 38

How conserved are flagella?

Answer 38

Very

TLR5 detects many types of flagella

Question 39

Subunit making up filament of flagella

Answer 39

Flagellin

Question 40

Structure of pili

Answer 40

1) Rod-shaped, hollow cylinder
2) Helical array of pilin protein subunits
3) Pilus tip mediates adhesion - can be pilin or another protein

Question 41

What is tissue tropism?

Answer 41

Tip of pilus determines tissue specific adhesion