GRAM POSITIVE RODS.PART 4

Question 1

What is the source of Clostridium botulinum spores?

Answer 1

The spores of Clostridium botulinum are widespread in soil.

Question 2

How do these spores contaminate vegetables and meats?

Answer 2

They contaminate vegetables and meats when these foods are canned or vacuum-packed without adequate sterilization. In such cases, the spores survive and germinate in the anaerobic environment.

Question 3

What disease does C. botulinum cause, and what is the nature of the toxin involved?

Answer 3

C. botulinum causes botulism, which is a rare and usually fatal foodborne disease. The toxin responsible for botulism is a lethal preformed neurotoxin that is ingested.

Question 4

Which types of foods are considered the highest-risk for botulism?

Answer 4

1. Alkaline vegetables, such as green beans, peppers, and mushrooms.
2. Smoked fish

Question 5

How can the toxin produced by C. botulinum be inactivated?

Answer 5

The toxin is relatively heat-labile, meaning it can be inactivated by boiling the contaminated food for several minutes.

Question 6

mention the types of toxins that causes human botulism

Answer 6

toxin types A, B, E and rarely type F

Question 7

explain the pahogenisis of clostridium botulinum

Answer 7

1. Botulinum toxin is absorbed from the gut and carried via the blood to
   peripheral nerve synapses, where it blocks release of acetylcholine.
2. It is a protease that cleaves the proteins involved in acetylcholine
   release.
3. The toxin is a polypeptide encoded by a lysogenic phage.

Question 8

clinical manifestation of for human botulism

Answer 8

Descending weakness and paralysis, including diplopia, dysphagia, and respiratory muscle failure, are seen.

Question 9

explain the lab diagnosis for clostridium botulinum

Answer 9

~The organism is usually not cultured.
~Botulinum toxin is demonstrable in uneaten food and the patient’s
serum by mouse protection tests.
~Mice are inoculated with a sample of the clinical specimen and will
die unless protected by antitoxin

Question 10

what is the treatment for clostridium botulinum

Answer 10

1. Trivalent antitoxin (types A, B, and E) is given, along with respiratory
   support.
2. The antitoxin is made in horses, and serum sickness occurs in about
   15% of antiserum recipients.

Question 11

prevention of clostridium botulinum

Answer 11

1. Proper sterilization of all canned and vacuum-packed foods is
   essential.
2. Food must be adequately cooked to inactivate the toxin.
3. Swollen cans must be discarded