Bacteria structure, function and infection

Question 1

What are extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL)?

Answer 1

Lecture 1, slide 12

Question 2

Why are we interested in infectious agents?

Answer 2

• Microbiome
• the human microbiota is abundant, complex, diverse and highly specific
• microbiome is a potential source of novel chemicals, e.g. antibiotics. Since bacteria in the microbiota are adapted to antagonise and compete with other bacteria in their niche.

-infections are the leading cause of death

Question 3

What is the difference between prokaryotes and eukaryotes?

Answer 3

Lecture 1, slide 23

Question 4

What are the different shapes of bacteria?

Answer 4

Lecture 1, slide 24-25

Question 5

What is the general structure of a bacterium?

Answer 5

Lecture 1, slide 26

Question 6

What are the differences between the structures of Gram + and Gram - bacteria?

Answer 6

Lecture 1, slide 28-32

Question 7

Why can some bacteria not be Gram stained?

Answer 7

Lecture 1, slide 29

Question 8

What colour are Gram- and Gram+ bacteria after Gram staining?

Answer 8

Gram+ : purple

Gram - : pink/red

Question 9

What have we learnt from bacteria?

Answer 9

Lecture 1, slide 34-41

Question 10

Why do bacteria continue to be a problem?

Answer 10

Lecture 1, slide 43-44

-mutations can be intra- and intergenomic

Question 11

Give an example of a community-acquired infection and an example of a hospital-acquired infection.

Answer 11

Lecture 1, slides 47-49

Question 12

What is CRISPR/Cas?

Answer 12

Lecture 2, slide 3

Question 13

What is tropism?

Answer 13

Lecture 2, slide 7

Question 14

What is the complement system?

Answer 14

Lecture 2, slide 9

Question 15

What is the structure of peptidoglycan?

Answer 15

Lecture 2, slide 13

Question 16

What is the difference between the structure of peptidoglycan in Gram- and Gram+ bacteria?

Answer 16

Lecture 2, slide 14

Question 17

What receptors detect peptidoglycans?

Answer 17

Lecture 2, slide 15

Question 18

How does peptidoglycan from gut microbiota contribute to homeostasis?

Answer 18

Lecture 2, slide 16

Question 19

What are teichoic acids and what is their function?

Answer 19

Lecture 2, slide 17

Question 20

What is the structure and function of the Gram- outer membrane?

Answer 20

Lecture 2, slide 18

Question 21

What is the structure of lipopolysaccharide?

Answer 21

Lecture 2, slide 19,21

Question 22

What is the role of the O-antigen and core polysaccharides? Give bacteria examples.

Answer 22

Lecture 2, slide 20

Question 23

What is the function of Lipid A? How is it recognised by the host and what happens after it is?

Answer 23

Lecture 2, slide 22

Question 24

What important functions do bacterial surface molecules/structures have during infection?

Answer 24

Lecture 2, slide 10

Question 25

Why is it important to know if a bacterium is Gram+ or Gram-?

Answer 25

Lecture 2, slide 24

Question 26

What are some important bacterial structures?

Answer 26

- capsules - flagella - pili - secretion systems - toxins

Question 27

What are bacterial capsules and what are their functions?

Answer 27

Lecture 2, slide 27

Question 28

How do bacterial capsules protect bacteria from host immunity?

Answer 28

Lecture 2, slide 28 - anti-phagocytotic - protects them from complement-mediated lysis (e.g. because the outer membrane of Gram- bacteria is a target for MAC)

Question 29

What is the structure and function of flagella?

Answer 29

Lecture 2, slides 30-32

Question 30

What is recognises flagellin? Why is flagellin used in vaccines?

Answer 30

Lecture 2, slide 33

Question 31

What is the structure and role of pili?

Answer 31

Lecture 2, slide 34

Question 32

How are some pili assembled? Which two pili are involved in host-pathogen interactions of many E.coli bacteria and what are their tip adhesions?

Answer 32

Lecture 2, slide 35

Question 33

What role do type 1 and P pili play in the pathogenesis of UPEC?

Answer 33

Lecture 2, slides 36-37 - they are virulence factors - Pap plays an important role in upper UTIs - type 1 pili plays an important role in lower UTIs

Question 34

What is the role of type 1 pilus in the pathogenesis of UPEC?

Answer 34

Lecture 2, slides 38-40

Question 35

Suggest a way to protect people from recurrent UTIs?

Answer 35

Lecture 2, slide 41 | -Fim ligands

Question 36

What are secretion systems and the different types?

Answer 36

Lecture 2, slide 42

Question 37

What is the structure and role of type three secretion systems?

Answer 37

Lecture 2, slide 43-44

Question 38

What are toxins and what are their roles? What are some different types of toxins?

Answer 38

Lecture 2, slide 45-47 (slide 47 is a list of exotoxins) -TSST: toxic shock syndrome toxin. Produced by Staphylococcus aureus. -speA and speB are produced by by Streptococcus pyogenes. -Superantigens: are a class of antigens that result in excessive activation of the immune system.

Question 39

What roles do bacterial surface structures have in colonisation and disease?

Answer 39

Lecture 3, slide 48