Clostridium botulinum

Introduction

Growing

What type of agar do you need? C. botulinum grows on ordinary blood agar.
Aerobic/anaerobic conditions? C. botulinum is an anaerobic bacterium.
C. botulinum is a mesophilic bacterium and grows best at 35-37 degrees Celsius. Its
growth-limiting pH is 4.3-4.5 and its inhibitory NaCl concentration in brine is 10%.
C. botulinum strains A, B, F do not grow under 10 degrees Celsius.

Molecular Diagnostics

History/General Information

A German poet and medical officer named Justinus Kerner first published the accurate and complete symptoms of food-born botulism between 1817 and 1822. C. botulinum the organism, was officially discovered by Emile Pierre van Ermengem in 1895. C. botulinum has been causing botulism toxin deaths for thousands of years.

C. botulinum generally lives in soil, ocean, and lake sediments.

C. botulinum is a bio-safety level 2 bacteria, in environments where it can be easily aerosolized it could be considered BSL-3.

Why Should We Care?

People care about C. botulinum because it produces one of the deadliest neurotoxins known. Botulism illness has a high rate of mortality and is considered a potential bioweapon by the CDC.

Clostridial toxin has many applications in medicine as it can be used to treat various neuronal and hyperactive muscle disorders. It is also used in cosmetic procedures to smooth facial wrinkles by relaxing the muscles underneath. It is estimated that the human LD50 for inhalation of clostridial toxin is only 1-3 nanograms per kg of body weight, roughly 154 ng for the average American. This is why it is perceived as a high-level bioterrorism threat.

Taxonomy

Domain: Bacteria

Phylum: Firmicutes

Class: Clostridia

Order: Clostridiales

Family: Clostridiaceae

Genus: Clostridium

Species: botulinum

Visualizing

C. botulinum is a gram positive bacteria species
The morphology of C. botulinum is bacillus. Some of which shown have terminal endospores.
Can be stained with crystal violet.

Differentiating

It can be confused for other members of the Clostridium genus. Attempting to identify it on Gideon by plugging in its relevant tests leads to a 3 percent guess from Gideon. Identifying C. botulinum is extremely challenging if using traditional diagnostic tests, such as plating. Doing chemical tests to detect the toxin, PCR, and mouse inoculation tests are more accurate ways to differentiate C. botulinum.

Treatment and prevention

Botulism can be prevented by making sure canned goods are heat treated or have conditions in which C. b. can not grow (low pH, high NaCl content, oxygen is present).
Botulism is treated with antitoxins, these disable the toxins produced by the bacteria, but do not reverse the damage already done. Botulism patients can spend months recovering in the hospital. Botulism in adults is also treated with antibiotics to prevent the bacteria from growing and producing more toxins. Interestingly, antibiotics are not used in infant botulism cases because they can cause an increase of toxin release as the bacteria die.
Penicillin is an effective antibiotic for adult botulism patients.

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