MCB 2610 Microbe of the Day: Clostridium botulinum

is Clostridium botulinum Gram-positive or negative

Gram-positive

Is Clostridium botulinum aerobic or anaerobic?

obilgate anaerobe: oxygen is toxic to them, NO oxygen needed

what shape is Clostridium botulinum

bacillus: rod-shaped

what does Clostridium botulinum produce

heat resistant endospores

what does Clostridium botulinum ferment

sugars or amino acids

where is Clostridium botulinum found

in soil, lakes sediments, decaying vegetation

what is the causative agent of botulism

Clostridium botulinum

what is botulism

a paralytic illness caused by a nerve toxin produced by C. botulinum

what are the 5 types of botulism

1. food borne

2. wound

3. inadvertent botulism

4. infant botulism

5. adult intestinal colonization

what is food borne botulism

caused by eating foods that

contain the botulinum toxin: canned food or trying to ferment when no oxygen is present

what is wound botulism

caused by a wound infected with C. botulinum, inject drugs or traumatic injury

ex: car accidents

what is inadvertent botulism

accidental overdose of

botulinum toxin

what is infant botulism

caused by consuming spores

or bacteria, which germinate in the intestine and release toxin (honey: babies should not have)

- infants do not have fully developed guts, so a few spores could germinate and grow

what is adult intestinal colonization

caused by consuming spores, which germinate in the intestine and release toxin

how does toxin act on Acetylcholine (Ach)

Ach causes muscles to contract

Toxin:

- Block Snare proteins from guiding Ach to the nerve membrane.

- Muscle is relaxed = Paralysis (do not contract)

- 8 known toxins A, B, C, D, E, F, G, and F/A hybrid (formerly H)

- A: Most common in the U.S., especially west of the Mississippi. Responsible for ~50% of foodborne outbreaks.

- Also widely used therapeutically (e.g., Botox).

- 2012: Toxin can get into the central nervous system

what are symptoms of botulism

- Double vision

- Blurred vision

- Drooping eyelids

- Slurred speech

- Difficulty swallowing

- Dry mouth

- Muscle weakness

what are specific symptoms of infant botulism

appear lethargic, feed poorly, are constipated, have a weak cry and poor muscle tone

If untreated botulism symptoms may progress to cause paralysis of respiratory muscles and airway obstructions, it could lead to

death

when do symptoms occur for foodborne botulism

symptoms can occur between 4 and 36 hours

what is the history of botulism

early 1800s- Dr. Justinus Andreas Christian Kerner

- Performed experiments on himself

- eating small amounts of so-called sour sausage- (Latin word for sausage, botulus)

- documented the signs and symptoms of botulism

- 1895- isolated from a Belgium scientist

- 1950- Dr. Vernon Brooks blocks the release of acetylcholine from motor nerve terminals

- BOTOX® was approved by the US FDA in December 1989- spasms

who discovered botulism and HOW

Dr. Justinus Andreas Christian

Kerner performed experiments on himself: eating small amounts of so-called sour sausage

epidemiology of botulism

rare 2024 (CDC):

- foodborne botulism: 9 cases

- infant botulism: 67 cases

- wound botulism: 12 cases

- other botulism (unknown): 5 cases

how do we diagnose botulism

- Serum analysis looking at BT toxin

- Needs to be caught early

what are treatments of botulism

- Treated with an antitoxin (NO HOSPITAL HAS IT, ONLY CDC) that blocks the action of the toxin circulating in the blood.

- If from food, inducing vomiting or enemas to remove contaminated food

- Antitoxin is available from the CDC

- Supportive care

- Antibiotics: depends on infection site (wounds)

- Can require several months of care in a hospital

- Patients who survive will have fatigue and shortness of breath for years

how to prevent botulism

1. boil home-canned foods for 10 minutes before eating, especially if you are unsure about the canning process

2. when in doubt, throw it out