2e. Clostridium

Question 1

What are 4 medically important species of clostridium?

Answer 1

1. C. tetani
2. C. botulinum
3. C. perfringens
4. C. difficile

Question 2

What are 2 clinical vignette clues for clostridum tetani infection?

Answer 2

1. Dirty puncture wound

2. Rigid paralysis

Question 3

What is the reservoir for Clostridum tetani?

Answer 3

Soil

Question 4

How is C. tetani transmitted?

Answer 4

Puncture wounds/trauma that includes human bites. Requires low tissue oxygenation (E(h)).

Question 5

What are 3 genus features of Clostridium?

Answer 5

1. Gram-positive rods
2. Spore forming
3. Anaerobic

Question 6

Describe the pathogensis of the C. tetani.

Answer 6

1. Spores germinate in the tissue, producing tetanous toxin (an exotoxin also called tetanospasmin).
2. It is then carried intra-axonally to CNS.
3. Binds to ganglioside receptors.
4. Blocks release of inhibitory mediators (glycine and GABA) at spinal synapse.
5. Excitatory neurons are unopposed: causes extreme muscle spasm.

Question 7

What are three clinical manifestation of tetanus?

Answer 7

1. Risus sardonicus
2. Opisthotonu
3. Extreme muscle spasm.

Question 8

How is C. tetani diagnosed?

Answer 8

Primarily a clinical diagnosis; organism is rarely isolated.

Question 9

What is the treatment for C. tetani?

Answer 9

1. Hyperimmune human globulin (TIG) to neutralize toxin PLUS metronidazole or penicillin.
2. Spasmolytuc drugs (diazepam); debride; delay closure.

Question 10

What substance inactivates the tetanus toxoid?

Answer 10

Formaldehyde.

Question 11

Describe a wound that is not tetanus prone.

Answer 11

Linear, 1cm deep cut, without devitalized tissue, without major contaminants, less than 6 hours old.

Question 12

Describe a wound that is tetanus prone.

Answer 12

Blunt/missle, burn, frostbite, 1 cm deep; devitalized tissue present with contaminants (e.g., dirt, saliva); any wound 6 hours old.

Question 13

What should be done with some with an incomplete vaccination or unknown vaccination history of tetanus with a wound that is not tetanus prone?

Answer 13

Vaccine.

Question 14

What should be done in patient with an incomplete/unknown vaccination with a tetanus prone wound?

Answer 14

Vaccine and Tetanus immunoglobin.

Question 15

What should be done with someone with a completed primary series of vaccination with a wound that is not tetanus prone?

Answer 15

Vaccine if more than 10 years since last booster.

Question 16

What should be done with someone with a completed primary series of vaccination with a wound that is tetanus prone?

Answer 16

Vaccine if more than 5 years since last booster shot.

Question 17

What are two distinguishing features of Clostridium botulinum?

Answer 17

1. Anaerobic

2. Gram-positive spore-forming rods.

Question 18

What is the transmission for clostridium botulinum?

Answer 18

Foodborne/traumatic implantation.

Question 19

What are 3 clinical key vignette clues of C. botulinum?

Answer 19

1. Home-canned alkaline vegetables.
2. Floppy baby syndrome (infant with flaccid paralysis).
3. Reversible flaccid paralysis.

Question 20

What is the reservoir for C. botulinum?

Answer 20

Spore survive in soil/dust.

Question 21

Describe the condition that C. botulinum germinates?

Answer 21

Germinates in most, warm, nutritious but nonacidic and anaerobic conditions.

Question 22

What is the mechanism of action of the botulinum toxin?

Answer 22

Absorbed by gut and carried by blood to peripheral nerve synapses. Blocks the release of acetylcholine at the myoneuronal junction resulting in a reversible flaccid paralysis.