Clostridium

Question 1

Clostridium botulinum

Answer 1

1. Toxin production is associated w/ the germination of endospores and growth of vegetative cells
2. Toxin is A-B neurotoxin; it acts at the neuromuscular junction and prevents the transmission of impulses from the nerve cell to the muscle
3. Botulinum toxin causes paralysis in which muscle tone is lacking (flaccid paralysis)

Question 2

Clostridium tetani

Answer 2

1. Tetanus neurotoxin (aka. tetanospasmin)
2. A-B toxin reaches the CNS and binds to nerve cells that control the contraction of various skeletal muscle – inhibiting muscle relaxation pathway

Question 3

Botulism

1. Etiology
2. Toxin
3. Signs and Symptoms

Answer 3

1. Clostridium botulinum: Obiligately anaerobic, endodpore-forming Gram (+) rod
2. Neurotoxin: highly specific for the synaptic end of the nerve, which blocks the release of ACh
3. Symptoms:
   a. Progressive flaccid paralysis (1-10 days)
   b. Nausea
   c. ALL suffer from double / blurred vision

Question 4

Botulinal toxin:
1. How does it function?
2.

Answer 4

1. Toxin is A-B neurotoxin; it acts at the neuromuscular junction and prevents the transmission of impulses from the nerve cell to the muscle
2. Botulinum toxin causes paralysis in which muscle tone is lacking (flaccid paralysis)
3. It doesn’t form in acidic environment. Ex. tomato canning

Question 5

Botulinal Types

Answer 5

1. Type A toxin: most virulent; Mortality rate is 60-70%

2. Type A endospore is the most heat-resistant of all C. botulinum strains.

Question 6

Infant botulism

Answer 6

Botulism organisms do not seem to be able to compete successfully with the normal intestinal microbiota, so the production of toxin by ingested bacteria almost never causes botulism in adults.
However, the intestinal microbiota of infants is not well established, and they may suffer from infant botulism.
Endospores related to ingestion of honey

Question 7

Treatment of botulism

Answer 7

Antitoxins aimed at the neutralization of A, B and E toxins are available and are usually administered together.

Question 8

Diagnosis of botulism

Answer 8

By the inoculation of mice w/ samples from patient serum, stool or vomitus specimens.
Different sets of mice are immunized w/ type A, B or E antitoxin. All the mice are then inoculated w/ the test toxin; if, for ex., those protected w/ type A antitoxin are the only survivors, then the toxin is type A.