Bacterial Neurotoxins

Question 0

What causes botulism, tetanus, and gas gangrene?

Answer 0

Clostridia

Question 1

Clostridia- catalase, anaerobes, gram

+or -?

Answer 1

Gram +
Catalase -
Strict Anaerobic

Question 2

Why can’t Clostridia break down h2o2?

Answer 2

They are catalase -

Question 3

What happens when Clostridia is in presence of 02?

Answer 3

Toxic superoxide anions accumulate– they lack the enzyme superoxide dismutase
And are strict anaerobes

Question 4

Can clostridium use oxygen as final e acceptor?

Answer 4

NO

Question 5

Paralytic illness die to neurotoxins made by c botulinum

Answer 5

Botulism

Food
Wound
Infant floppy baby syndrome

Question 6

Which type of botulism has preformed toxin and which is the toxin made in vivo?

Answer 6

Infant made in vivo and food poisoning is preformed toxin

Question 7

Most common botulinum toxin forms

Answer 7

A b and e

Question 8

Can c botulinum be killed w heat?

Answer 8

Spores are heat resistant

Question 9

Mode of action for c botulinum?

Answer 9

Interferes w release of ach at neuromuscular junction results in flaccid paralysis

Question 10

BoNT

Answer 10

C botulinum

Question 11

C botulinum is what kind of enzyme?

Answer 11

BoNT is a endoprotease

Question 12

How does c botulinum interrupt nmj?

Answer 12

The neurotoxin cleaves a price of neuro secretory apparatus like a membrane protein (snare proteins) so seiches can’t release ach

Question 13

How does good poisoning develop?

Answer 13

C botulinum spores contaminate canned or packed food and germinate in the alkaline pH!
Anaerobic conditions allow vegetative form and toxin is produced
Absorbed by body and toxin is NOT killed by digestive enzymes

Question 14

Clinical manifestations of food botulism?

Answer 14

Dry mouth, hard to swallow, visual disturbances, speech issues, descending paralysis
But NO FEVER
recovered people don’t have antitoxin in blood

Question 15

Floppy baby syndrome

Answer 15

Gi Tract colonized from env source (honey?) and toxin produced in vivo
Treatment is BIG-iv - intravenous botulism immune globin –human derived antitoxin antibodies

Question 16

Deadliest toxin with no known antidote

Answer 16

Botulinum toxin type H

Question 17

Good uses of Botox

Answer 17

Muscle spasms
Migraines
Over active bladders
Strabismus
Cosmetic use

Question 18

Neurotoxin of tetanus

Answer 18

Tetanospasmin

Question 19

What makes Tetanospasmin?

Answer 19

Clostridium tetani

Question 20

Spores of c tetani is found in

Answer 20

Feces and soil

Question 21

Clinical symptoms of tetanus

Answer 21

Trismus (lockjaw)
Risus sardonicus(sustained grin)
Stiff neck 
Hard to swallow, rigid abdominals
Voluntary muscle spasm

Question 22

C tetani mode of action

Answer 22

Cleaves VAMP(synaptobrevin)
And prevents release of neurotransmitter glycine from inhibitory intereurons in spinal cord
Leads to stimulation of muscle contractions

Question 23

How does tetanus get in body?

Answer 23

Puncture wounds or burns

Question 24

Inside body what happens with c tetani

Answer 24

Spores get in through wound and reverts to vegetative form w help from organisms and necrotic tissue
Toxin spreads in blood and lymph associated w nerves
Toxin combines with gangliosides

Question 25

Treatment for tetanus?

Answer 25

Antitoxin- doesn’t neutralize toxin already bound to nerve tissue

Immunization
Prevention - TETANUS IMMUNE GLOBIN(tig)

Question 26

What does metronidazole do

Answer 26

Inhibits c tetani growth