Chapter 9 - Bacteria Flashcards
what does cell membrane damage cause
cell death
damage is proportional to _____
number of bacteria inside cell
how are host cells lysed using cell mediated immuntiy
CTL activation uses perforin and granzymes to kill cells displaying MHC class I
what are the mechanisms of cell death
-growth of pathogen within host cells
- cell- mediated immunity
- membrane damaging toxins - apoptosis
what is uncontrolled inflammation due to
exaggerated adaptive immune responses = hypersensitivities
what is involved in a health inflammation response
-increased blood supply (redness)
- increased vascular permeability (edema)
- chemotaxis (infiltration by phagocytes and lymphocytes)
what is type I hypersensitivity
allergy but can lead to anaphylaxis and shock
what is type II hypersensitivity
bound antibodies leading to complement and leukocyte activation to surfaces
what is type III hypersensitivity
bound antibodies leading to complement and leukocyte activation to soluble molecules then immune complex deposition
what is type IV hypersensitivity
inflammation by purely CMI responses not antibodies
what are toxins
microbial product or component that can injure another cell or organism at low concentrations
what ways do toxins act
- modulation of targets inside a host cell
- action on surface of a host cell
- action in the ECM
where are toxin encoding genes carried
on plasmids or temperate bacteriophage genomes
what proteins encode the proteins that make up cholera toxin
ctxA and ctxB
what are exotoxins secreted by
pathogens
- type I or type II secretion systems
