Micro-Toxins

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S. aureus toxins

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against immunity
-IgA protease,
protein A- binds FC region of Ig. inhibits complement activation, opsonization and phagocytosis
-Capsule-prevent phagocytosis
-penicillinase-destroys penicillin
tunnel throu tissue
-hyaluronidase-breaks peptidoglycans
-staphylokinase-lyses fibrin
clots
lipases-hydrolyze lipids
exotoxins
-exfoliatin-scalded skin syndrome
-enterotoxin-food poisoning (heat stable)
-TSST- stimulates TNF, IL-1
altered penicillin binding protein

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Group A strep

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M protein-inhibits compliment, prevents phagocytosis
antibodies to it cross react with human antigens- rheumatic fever
tissue invasive toxins (abcess, skin infections, systemic)
-streptolysin O-destroys RBCs
-Streptokinase- lyse fibrin clots
-hyaluronidase-break down peptidoglycans
-DNAses-hydrolyze DNA
Anti-C5a peptidase-anti compliment
strep pyrogenic toxin- activates mediators of sepsis, eg IL-1 (causes scarlet fever)
erythrogenic toxin-causes toxic shock-like syndrome, and scarlet fever

Front 3

strep. pneumo

Back 3

IgA protease
Acquires ability to form capsules by transformation

Front 4

enterococci

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penicillin G resistant
some are vanco resistant!

Front 5

Clostridium tetani

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tetanospasmin.
taken up by motor end plate, transported to CNS, inhibits Glycine and GABA

Front 6

C. Botulinum

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botulinum toxin - preformed, heat labile neurotoxin
most potent exotoxin ever!

Front 7

C. perfringens

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alpha toxin- lecithinase
myonecrosis, hemolysis

Front 8

C. difficille

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cytotoxins-exotoxins that kill enterocytes
Toxin A- diarrhea, neutrophil chemoattractant
Toxin B-cytotoxic to colonic cells-actin depolymerization, loss of cytoskeleton integrity

Front 9

Corynebacterium diptheriae

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Exotoxin encoded in beta -prophage. C. dipth. acqires it thru lysogeny
A/B toxin
B-bind to tissue
A-ADP ribosylation of Elongation factor 2 (EF 2)
(think about it as a human antibiotic, just as tetracycline would inhibit protein synthesis in bacteria)

Front 10

Anthrax-bacillus anthracis

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Edema factor- Calmodulin dependent adenylate cyclase. increases cAMP in neutrophils and macrophages, inhibits their phagocytotic action, causes edema
protective antigen- allows EF to get into cells
lethal factor-zinc metalloprotease, inactivates protein kinase, causes release of TNF and IL-1 from macrophages, kills affected cell.

Front 11

Neisseria

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IgA protease
pili- adherence. Also, antigen variation

Front 12

Hemophilus influenza

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IgA protease
Capsule- type B (there is a HiB vaccine against it, its conjugated to diptheria toxoid)

Front 13

Enterobacteria

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O antigen- LPS
V1/ K1 antigen-capsule
H antigen-flagella

Front 14

ETEC

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LT/ heat labile toxin.
B Subunit- binds GM1 gangliosides on intestinal cell membrane
A subunit-ADP ribosylation of GTP-binding protein. Activates adenylate cyclase, increase cAMP, induce NaCl secretion

ST/ heat stable toxin.
Binds to receptor on intestinal brush border, activates guanylate cyclase, increase scGMP, inhibits reabsorption of NaCl. Osmotic diarrhea

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EHEC (0157.H7)

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Shiga-like toxin

Remember
Shiga toxin
B subunit- binds intestinal cells
A subunit-inactivates 60s ribosomal subunit, inhibits protein synthesis, kills intestinal epithelial cells.
(inhibits protein synthesis the same way antibiotics inhibit bacterial protein synthesis! smart bugger!)
Rm. E.coli usually ferments sorbitol and produces glucuronidase, but the one with Acquired shiga toxin doesnt have these

Front 16

EIEC

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shiga- like toxin

Remember
Shiga toxin
B subunit- binds intestinal cells
A subunit-inactivates 60s ribosomal subunit, inhibits protein synthesis, kills intestinal epithelial cells.
(inhibits protein synthesis the same way antibiotics inhibit bacterial protein synthesis! smart bugger!)
Rm. E.coli usually ferments sorbitol and produces glucuronidase, but the one with Acquired shiga toxin doesnt have these

Front 17

Vibrio cholerae

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Heat labile toxin
B Subunit- binds GM1 gangliosides on intestinal cell membrane
A subunit-ADP ribosylation of GTP-binding protein. Activates adenylate cyclase, increase cAMP, induce NaCl secretion

Front 18

Campylobacter Jejuni

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Heat labile toxin,
B Subunit- binds GM1 gangliosides on intestinal cell membrane
A subunit-ADP ribosylation of GTP-binding protein. Activates adenylate cyclase, increase cAMP, induce NaCl secretion

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Bacillus cereus

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Heat Labile Toxin
B Subunit- binds GM1 gangliosides on intestinal cell membrane
Heat labile toxin
A subunit-ADP ribosylation of GTP-binding protein. Activates adenylate cyclase, increase cAMP, induce NaCl secretion

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Yersinia Enterolytica

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Heat Stable Toxin:
Binds to receptor on intestinal brush border, activates guanylate cyclase, increase cGMP, inhibits reabsorption of NaCl. Osmotic diarrhea

Front 22

Salmonella

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Vi Capsule
Facultative intracellular
flagella
(there is a vaccine for S. typhi-Ti21 oral, live)

Front 23

Shigela

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Shiga toxin
B subunit- binds intestinal cells
A subunit-inactivates 60s ribosomal subunit, inhibits protein synthesis, kills intestinal epithelial cells.
(inhibits protein synthesis the same way antibiotics inhibit bacterial protein synthesis! smart bugger!)

Front 24

Klebsiella

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Capsule
Also causes endotoxin shock

Front 25

Bordatella pertussis

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Pertussis toxin
B subunit-binds cells
A subunit-permanently disables inhibitory G proteins. (turns the off off) Activates stimulatory G proteins, cAMP goes up in macrophages and neutrophils, inhibits phagocytosis)
filamentous hemagglutinin-binds ciliated epithelial cells
tracheal cytotoxin- damages respiraroty epithelial cells
Pertussis toxin also inhibits chemokine receptors. Promotes lymphocytosis so bad, you think its Leukemia (Leukemoid rxn)

Front 26

Pseudomonas aeruginosa

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Pseudomonas exotoxin A
B subunit binds
A subunit- ADP ribosylates elongation factor 2 (EF2), inhibits translation of mRNA. (Just like C. diptheriae)
Exotoxin a targets the liver, Diptheria toxin targets the heart.
Elastase-degrades elastin in blood vessel walls
phospholipase C-degrades cellular membranes
Pyocyanin- generates reactive oxygen specis

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Yersinia Pestis

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Capsular antigen (Vi variant)- resists phagocytosis

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M. tuberculosis

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Mycolic acid-
Cord Factor (2 mycolic acids and a trehalose) inhibits neutrophils, damages mitochondria, releases TNF-cachexia.
sulfatides-(sulphatides attached to mycolic acid) inhibits phagosome from from fusing with lysosome
Wax D- a mycoside that acts as adjuvant, enhances antibody formation against pathogen, activates protective cellular immunity

Front 29

chlamydiae

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modifies membrane bound compartment, prevents phagosome-lysosome fusion

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Mycoplasma pneumoniae

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PI protein-attaches to respiratory epithelial cells.
IgM is produced against the PI protein, but can cross react with RBC (cold agglutinins)

Front 31

E. Coli

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Acquires ability to form pili by conjugation.
Pili- adherence in UTIs

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Antibiotic resistant bacteria

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Acquire resistance genes through conjugation

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Bee sting

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Hyaluronidase
Phospholipase
Proteins that initiate an IgE rxn (Allergy, analphylaxis)