03 - Pathogenic Mechanisms of Bacteria (Part II)

Question 1

Answer 1

Question 2

(Strategies Directed against acquired immunity)

(Suppression of Antibodies)

1. Here the invading organism targets what cells?
2. the organism prevents what?

(example)

1. mycobacterium tuberculosis (causes tuberculosis) reduces what response?

Answer 2

1. those of the immune system that specifically react to them
2. the body from mounting an immune response against it
3. the interleukin-2 response

Question 3

(Strategies Directed against acquired immunity)

(Hiding Against Cells)

1. many bacteria avoid by hiding inside cells of immune system
2. do they present antigens that will provoke an immune response?
3. They multiply inside these cells, and then further invade when?
4. give three examples… what do they invade?

Answer 3

2. no
3. when they are greater in number
4. brucella, listeria, mycobacterium tuberculosis; macrophages

(look at next two pages of slides)

Question 4

Answer 4

Question 5

1. What bacteria spores persist at burial sites of anthrax infected animals (sometimes over 70 years!)

Answer 5

1. bacillus anthraces

(first sign in animals… enlarged spleen…. don’t open up carcass cause spores can spread around)

Question 6

(Toxins produced by bacteria causes tissue damage)

1. What is a toxin excreted by a microorganism?
2. How does this cause damae to the host?
3. Where do these act on surface of host cells?
4. Well known exotoxins include botulinium toxin… produced by what two bacteria?

Answer 6

1. an exotoxin
2. by destroying cells or disrupting normal cell metabolism
3. on the surface
4. clostridium botulinium and corynebacterium diphtheriae

Question 7

(Toxins Produced by bacteria cause tissue damage)

1. What toxins are part of the outer membrane of the cell wall of gram-negative bacteria?
2. Is it secreted by bacteria like exotoxin?
3. Endotoxins trigger phagocytes to release what?

Answer 7

1. endotoxins
2. no… is a structural component in bacteria which is released when bacteria are lysed
3. cytokines (local or systemic symptoms)

Question 8

(Strategies Directed Against Phagocytes)

(inhbit chemotaxis)

1. chemotaxis lead what where?
2. some bacteria produce toxins which inhbit movement of chemotaxis… what is an example of this

Answer 8

1. phagocytes to site of infection
2. staphylococcus aureus

Question 9

(inhibition of phagocytosis)

1. Phagocytes work by grabbing, then engulfing bacteria… how do some bacteria avoid this?

Answer 9

1. by not giving phagocytes anything to grab onto

Question 10

(killing the phagocyte)

1. Some bacteria release toxins that kill phagocytes…

name 4

Answer 10

1. mycobacterium tuberculosis
2. streptococcus pyogenes
3. some staphylococci
4. bacillus anthraces (anthrax)

Question 11

(Colonization of the phagocyte)

1. bacteria that allow themselves to be phagocytized… but resist being killed once inside
2. Many bacteria use what cell as sancuatary? what is the benefit?
3. what are two bacteria that use this strategy?

Answer 11

2. macrophages… other immune cells won’t bother them
3. mycobacterium leprae and mycobacterium tuberculosis

Question 12

(Indirect mechanisms of tissue by pathogens)

Question 13

Question 14

Question 15

Question 16

(Toxins)

(tell me what make each toxin)

1. diptheria toxin
2. alpha-toxin
3. cholera toxin
4. toxic shock

Answer 16

1. C. diptheriae
2. S. aureus
3. V. cholera
4. S. aureus

Question 17

(Superantigens)

1. Certain species produce superantigens, why are they called this?
2. Superantigens overstimulate T cells by binding to what?

what causes shock?

what is the most important of these?

3. What can high levels cause?

Answer 17

1. ability to polyclonally activate large fractions (2-20%) of T-cell population
2. the MHC molecule and the TCR

overproduction of cytokines

TNF-alpha

3. severe and life-threatening symptoms… including shock and multiple organ failure

Question 18

(Antibiotic Induced Infections)

1. Treatment with antibiotics can cause massive death of commensal organisms that normally colonize the colon
2. what can happen after that?
3. give an example?

Answer 18

2. pathogenic bacteria proliferate quickly
3. clostridium difficile

Question 19

then he skipped a bunch of slides - starting at p68 - so figure out whether or not you need to know these