How can we help?

You can also find more resources in our Help Center.

36 terms

virulence, exotoxins, endotoxin

STUDY
PLAY
virulence factors function to
promote evasion of host immune response
Staphylococcus aureus - virulence factor?
Protein A
Staphylococcus aureus - virulence factor function?
binds Fc region of Ig to prevent opsonization and phagocytosis
Streptococcus pneumoniae - virulence factor?
IgA protease (cleaves IgA in order to colonize respiratory mucosa)
Haemophilus influenzae type B - virulence factor?
IgA protease (cleaves IgA in order to colonize respiratory mucosa)
Neisseria - virulence factor?
IgA protease (cleaves IgA in order to colonize respiratory mucosa)
mnemonic for bacteria which secrete IgA protease
SHiN (S. pneumoniae, H. influenzae type B, Neisseria)
Group A streptococcus (Streptococcus pyogenes) - virulence factor?
M protein
Group A streptococcus (Streptococcus pyogenes) - virulence factor function?
prevent phagocytosis
exotoxin characteristics
polypeptide secreted from cells, encoded on plasmids/bacteriophages, induces antitoxins, not very heat stable
endotoxin characteristics
lipopolysaccharide on outer cell membrane of most Gram negative bacteria, encoded on bacterial chromosome, induces TNF and IL-1 (fever and shock), poorly antigenic, heat stable
Corynebacterium diphetheriae - exotoxin function?
inactivates elongation factor (EF-2) via ADP-ribosylation
Pseudomonas aeruginosa - exotoxin function?
inactivates elongation factor (EF-2) via ADP-ribosylation
Shigella - exotoxin function?
inactivates 60S ribosome by cleaving rRNA
Enterohemorrhagic E. coli (EHEC) - exotoxin function?
inactivates 60S ribosome by cleaving rRNA
Enterotoxigenic E. coli heat-labile - exotoxin function?
overactivates adenylate cyclase --> increases cAMP --> increases Cl- secretion in gut and H20 efflux
Enterotoxigenic E. coli heat-stable - exotoxin function?
overactivates guanylate cyclase --> increases cGMP --> decreases reabsorption of NaCl and H20 in gut
Yersinisa enterocolitica - exotoxin function?
overactivates guanylate cyclase --> increases cGMP --> decreases reabsorption of NaCl and H20 in gut
Bacillus anthracis - exotoxin function?
mimics adenylate cyclase enzyme --> increases cAMP
Vibrio cholerae - exotoxin function?
overactivates adenylate cyclase by permanently activating Gs --> increases cAMP --> increases Cl- secretion in gut and H20 efflux
Bordetella pertussis - exotoxin function?
overactivates adenylate cyclase by inactivating Gi --> increases cAMP --> impairs phagocytosis to permit microbe survival
Clostridium tetani - exotoxin function?
cleaves SNARE protein required for (inhibitory - GABA and glycine) neurotransmitter release
Clostridium botulinum - exotoxin function?
cleaves SNARE protein required for (stimulatory - ACh) neurotransmitter release
Clostridium perfringens - exotoxin function?
phospholipase (lecithinase) which degrades tissue, cell membranes --> myonecrosis and hemolysis
Streptococcus pyogenes - exotoxin?
Streptolysin O
Clostridium perfringens - exotoxin?
Alpha toxin
Streptococcus pyogenes - exotoxin function?
lyses RBCs, contributes to beta-hemolysis
Streptococcus pyogenes - superantigen?
Exotoxin A
Streptococcus pyogenes - superantigen function?
brings MHC II and TCR in proximity to cause overwhelming release of IFN-gamma and IL-2 --> shock
Staphylococcus aureus - superantigen function?
brings MHC II and TCR in proximity to cause overwhelming release of IFN-gamma and IL-2 --> shock
Staphylococcus aureus - superantigen?
TSST-1
exfoliative toxin causes
scalded skin syndrome
enterotoxin causes
food poisoning
Bacillus anthracis - exotoxin?
Edema factor
Pseudomonas aeruginosa - exotoxin?
Exotoxin A
endotoxin activates
macrophages, alternative complement pathway, Hageman factor (XII)