Microbiology-Neurotoxins

Question 1

What are the special characteristics of strict anaerobes?

Answer 1

They can’t use oxygen as an electron receptor, they can’t break down H2O2 and superoxides accumulate in the presence of oxygen.

Question 2

What diseases are caused by Colostridia?

Answer 2

Botulism, tetanus, gas gangrene, food-poisoning, CDAD (C. Diff) and pseudomembranous colitis

Question 3

What type of bacteria is Clostridia?

Answer 3

Gram + rods, spore formers

Question 4

What are the three different flavors of botulism?

Answer 4

Food, wound and infant (most common)

Question 5

A mother brings a baby to see the doctor and is diagnosed with floppy baby syndrome. You decide to treat the baby with medication. What medication do you give?

Answer 5

A heptavalent anti-toxin. Botilinum toxin has 7 distinct serotypes, if you don’t know the serotype treat them all.

Question 6

What are the most common serotypes of botulism?

Answer 6

Types A, B and E.

Question 7

Why does grandma boil green beans when she cans?

Answer 7

She is terrified of botulism because it doesn’t get killed by her stomach when she eats it, so she boils it for 20 minutes.

Question 8

Why do they call botulism poisoning in a baby floppy baby syndrome?

Answer 8

It interferes with ACh release at the neuromuscular junction and causes flaccid paralysis.

Question 9

What are the two components of the botulinum toxin?

Answer 9

A = enzymatic active part and B = binding component

Question 10

What metal could you eliminate from a cell to limit destruction by BoNT?

Answer 10

Zinc. It must have zinc in order for the enzymatic portion to function

Question 11

How does botox get rid of wrinkles?

Answer 11

It relaxes the muscles in the skin

Question 12

What are typical symptoms of someone who has ingested food-borne botulin toxin?

Answer 12

No fever, dry mouth, difficulty swallowing, visual disturbances, speech difficulties and descending paralysis. Although it was ingested, they will not have digestive symptoms.

Question 13

How do most deaths occur in botulin toxin poisoning?

Answer 13

Respiratory paralysis or cardiac arrest.

Question 14

Why are babies more likely to get botulism?

Answer 14

Spores are more likely to germinate in their digestive tract than in adults. This is why you don’t feed babies honey, it has spores in it.

Question 15

What is babyBIG?

Answer 15

Human antitoxin antibodies against toxins A and B from volunteers that were injected with inactivated botulin toxoid

Question 16

A mother brings her child to see you. The country she comes from commonly ties horsehair around the umbilical cord during birth. The child is having muscle spasms. How are these spasms produced?

Answer 16

Tetanus toxin cleaves VAMP (synaptobrevin) and prevents release of neurotransmitter glycine from inhibitory neurons in spinal cord, resulting in continual muscle contraction.

Question 17

Why is stepping on a nail a risk for tetanus?

Answer 17

Spores are introduced into the wound by the nail. Other organisms in the wound may make the environment more anaerobic so the bacteria can make the toxin. The toxin then travels to the nerves.

Question 18

What are the clinical presentations of tetanus?

Answer 18

Lockjaw, stiffness of the neck and respiratory failure.

Question 19

How do you treat tetanus?

Answer 19

Antitoxin stops the toxin but does not stop the symptoms. You must treat the symptoms, nerve recovery is extremely slow.

Question 20

If you haven’t been immunized and have a very dirty wound what can you do to prevent tetanus?

Answer 20

TIG (human tetanus immune globin as passive immunity therapy) and metronidozole which inhibits growth of anaerobes.