Bacterial toxins

Question 1

STAPH. aureus
toxin?
mechanism?
disease?

Answer 1

ALPHA TOXIN

• pore forming cytolysin
• tissue damage, hemolysis

Question 2

STREP pyogenes
toxin?
mechanism?
disease?

Answer 2

STREPTOLYSIN O (similar to as staph aureus)

• pore forming cytolysin
• tissue damage cytolysin

Question 3

LISTERIA monocytogenes
toxin?
mechanism?
disease?

Answer 3

LISTERIOLYSIN O

• formes pores in phagosome
• allows listeria to survive in phagocytes

Question 4

CLOSTRIDIUM perfringens
toxin?
mechanism?
disease?

Answer 4

ALPHA TOXIN

• hydrolyzes eykaryotic phospholipid
• tissue destruction

Question 5

STAPH aureus
superantigen (1 of 2)?
mechanism?
disease?

Answer 5

TOXIC SHOCK SYNDROME TOXIN

• binds TCR, activating them, releasing TNF alpha and IL1
• causes rash, hypotension, capillary leakage, fever

Question 6

STREP pyogenes
superantigen?
mechanism?
disease?

Answer 6

EXOTOXIN A / PYROGENIC TOXIN (similar to TSST)

• binds TCR, activating them, releasing TNF alpha and IL1
• causes rash, hypotension, capillary leakage, fever ***CARDIOTOXICITY

Question 7

STAPH aureus
superantigen (2 of 2)?
mechanism?
disease?

Answer 7

ENTEROTOXIN B

• binds TCR
• vomiting diarrhea

Question 8

CORYNEBACTER diphtheriae
AB toxin?
mechanism?
disease?

Answer 8

DIPHTHERIA TOXIN

• A-part ADP ribosylates the eukaryotic elongation factor 2 ==> inhibits protein synthesis
• sore throat, pseudomembrane, slight increase in temp.

Question 9

PSEUDOMONAS aeruginosa
AB toxin?
mechanism?
disease?

Answer 9

EXOTOXIN A (similar to coryne. diptheria)

• ADP ribosylates the eukaryotic elongation factor 2 ==> inhibits protein synthesis ** mainly in liver cells **
• jaundice, increased risk of death if septicemia

Question 10

SHIGELLA dysenteriae
AB toxin?
mechanism?
disease?

Answer 10

SHIGA TOXIN

• A-part cleaves 60S ribosomes ==> stops protein synth. and kills cells
• damages colonic mucosa, may cause hemolytic uremic syndrome

Question 11

ENTEROHEMORRHAGIC E Coli
AB toxin?
mechanism?
disease?

Answer 11

VEROTOXIN (shiga-like)

• A-part cleaves 60S ribosomes ==> stops protein synth. and kills cells
• damages colonic mucosa, hemorrhagic colitis, hemolytic uremic syndrome

Question 12

VIBRIO cholerae
AB toxin?
mechanism?
disease?

Answer 12

CHOLERA TOXIN

• ADP ribosylates Gs, ==> activates adenylyl cyclase and increases [cAMP]
• fluid loss, rice water stool, electrolyte loss

Question 13

ENTEROTOXIC E coli
AB toxin?
mechanism?
disease?

Answer 13

E COLI LABILE TOXIN (similar to cholera, but not as severe)

• ADP ribosylates Gs, ==> activates adenylyl cyclase and increases [cAMP]
• fluid loss, rice water stool, electrolyte loss

Question 14

BACILLUS anthracis
AB toxin?
mechanism?
disease?

Answer 14

ANTHRAX TOXIN

• tripartate toxin: edema factor activates adenyl cyclase, lethal factor kills
• malignant pustules in skin infection with necrotic escar; respiratory infection causes septic shock

Question 15

BORDETELLA pertussis
AB toxin?
mechanism?
disease?

Answer 15

PERTUSSIS TOXIN

• inhibits the regulator of adenylyl cyclase with ADP ribosylation ==> increasing [cAMP]
• increase repiratory secretion, cecreases phagocytic function, encephalopathy

Question 16

CLOSTRIDIUM tetani
neurotoxin?
mechanism?
disease?

Answer 16

TETANUS TOXIN

• inhibits release of inhibitory transmitters like GABA
• rigid paralysis

Question 17

CLOSTRIDIUM botulinism
neurotoxin?
mechanism?
disease?

Answer 17

BOTULINISM TOXIN

• blocks the release of neurotransmitters
• flaccid paralysis

Question 18

CATALASE enzyme
activity?
what does it tell you?

Answer 18

CATALASE

• converts h202 ==>h2o + o2
• differentiates staph (+) from strep, or mycobacteria species

Question 19

UREASE enzyme
activity?
what does it tell you?

Answer 19

UREASE

• hydrolyzes urea
• involved in UTI bacteria and H Pylori

Question 20

COAGULASE enzyme
activity?
what does it tell you?

Answer 20

COAGULASE

• fibrinogen ==> fibrin clot
• differentiates staph, or identifies Yersinia pestis