Bacterial Toxins

Question 1

Exotoxins

Answer 1

produced by and released by bacteria

Gram + w/ plasmids or bacteriophages coding for the exotoxin protein

antigenic- tetanus and diphtheria toxoid vaccines

Question 2

Neurotoxins

Answer 2

interfere w/ neural transmission

botulinum toxin, tetanus toxin

Question 3

Enterotoxins

Answer 3

affect intestines

Shigella, Vibrio cholerae

Question 4

Superantigens

Answer 4

exotoxins that bind MHCII receptor and T cell receptor simultaneously

• -> polyclonal expansion of T cells
• -> massive immune response w/ release of large amount of cytokines

S. aureus, S. pyogenes (group A strep)

Question 5

Endotoxin effect on macrophages

Answer 5

IL1, IL6 –> fever
TNF –> fever, cell death, cachexia
NO (vasodilator) –> hypotension, development of septic shock

Question 6

Endotoxin effect on complement

Answer 6

C3a (release histamine, increase vascular permeability) –> hypotension, development of septic shock

C5a –> N0 chemotaxis

Question 7

Endotoxin effect on tissue factor

Answer 7

Coagulation cascade –> DIC
-W/ gram - sepsis

microthrombi throughout body consumes coagulation factors and platelets –> bleeding issues

Question 8

Bacterial growth curve

Answer 8

Exponential/log phase: cell division
-vulnerable to abx, radiation

Stationary phase: spore formation, nutrient depletion, toxins accumulate

Death phase: prolonged nutrient depletion