What kind of bacteria is Clostridium Botulinum?
It can be found as a single bacterium, in pairs or chains.  It is a spore forming bacteria. Spores of Clostridium botulinum have the ability to remain in a dormant state until environmental conditions allow them to grow. These spores are very resistant to environmental effects. It is very hard to kill them. The spores will grow under favorable conditions, and will begin to produce one of the most powerful toxins ever known, named botulin. Clostridum botulinum can have multiple habitats, mainly in the soil and possibly food products. This bacterium is also mesophilic, with an optimal temperature of around 37 degrees.

Clostridium botulinum consists of seven different subtypes, named with the letters A-G. Each of these subtypes, produce different botulin toxins. Types A, B, E, F and G are pathogen for humans.

Botulinum is a very powerful toxin. The botulinum toxins most active forms are as dichain molecules. Toxicity is related to the L-Chain which blocks primarily on peripheral cholinergic synapses to prevent the calcium mediated release of acetylcholine. This is most likely to be due to interfering with the mechanism of exocytosis.  It is the place where vesicles containing neurotransmitters fuse with the cell membrane. The toxin prevents the propagation of action potentials to the muscle fibers. Inhibition of muscle contractions will induce paralysis. Asphyxia is the main cause of death in this bacterial infection due to the inability of the chest muscles to contract and allow the breathing process. Muscle weakness and impaired vision are other effects of this toxin.

Botulinum toxins are absorbed from the intestinal tract and carried through the bloodstream to the neuromuscular endings. From the wounds, the toxins are carried through the lymphatic system to the neuromuscular endings.

What is Botulism?

Botulism is a very dangerous, but luckily a rare bacterial infection caused by Clostridium botulinum.  It is characterized by symmetrical, descending, flaccid paralysis of motor and autonomic nerves usually beginning with cranial nerves. Three main forms of botulism are:

  • Infant botulism – the spores of Clostridium botulinum grow in a baby’s intestinal tract. It typically occurs between the ages of 2 and 6 months.
  • Foodborne botulism – Clostridium botulinum produces its toxin in environments with little oxygen, such as in canned food.
  • Wound botulism – the bacterium enters the human body through a cut or a wound in the body. Usually, tetanus occurs after deep penetrating wounds.

Signs and symptoms of Botulism

After eating food contaminated with Clostridium botulinum, the signs and symptoms usually begin between 18 and 36 hours. However, this period in some cases can range from a few hours to several days, depending on the amount of the toxin ingested. These signs and symptoms include: dry mouth, difficulty swallowing or speaking, trouble breathing, facial weakness, nausea, vomiting, abdominal cramps, blurred or double vision, drooping eyelids, paralysis, etc.

Wound botulism occurs after a cut, burn or any other wound in the surface or deeper into the body. These signs and symptoms include: infection of the wound, difficulties breathing, muscular weakness, blurred or double vision, paralysis, etc.

Signs and symptoms in infant botulism include: constipation, often as the first noticeable sign, irritability, weak cry, floppy movements due to muscle weakness, trouble controlling the head, tiredness, difficulties sucking and feeding, breathing problems, paralysis, etc.

Complications caused by botulism include: difficulties swallowing, speaking, breathing, fatigue, shortness of breath, muscular weakness, etc.

How is Botulism diagnosed?

Botulism should be suspected in a patient with sudden onset of gastrointestinal symptoms associated with cranial nerves dysfunction and autonomic symptoms. Treatment should be started without waiting for the results. Confirmatory tests make take days to perform, and waiting for the tests can be too late. The suspected food, stool and serum should be examined for the presence of Clostridium botulinum. The most reliable test is the mouse inoculation test.


How is Botulism treated?

Botulism is considered a medical emergency and all the forms of botulism can be lethal. If botulism is suspected, immediate reaction is necessary.

There is no cure for Botulism. Treatment is only supportive against signs and symptoms. Although antitoxins do exist for this disease, by the time the symptoms of botulism show the toxin is irreversibly bound. At most the antitoxins may serve to neutralize the unbound toxin, but it is unable to reverse the binding of any toxins that are already exacting their effect.

If the infection is through ingested food, induced vomiting, medications to induce bowel movements are part of the treatment. If the infection is through a wound, surgically removal of the infected tissue is necessary.

If botulism is suspected, antitoxin injections, reduces the risk of complications. The antitoxin attaches itself to toxin that’s still circulating in your bloodstream and keeps it from harming your nerves. The antitoxin cannot, however, reverse the damage that’s been done. Fortunately, nerves do regenerate. Many people recover fully, but it may take months and extended rehabilitation therapy. Botulism immune globulin is used to treat this infection in infants.

Aspiration and mechanical ventilation might be necessary for couple of weeks, until the effects of the toxin gradually lessen.

Rehabilitation is usually needed to improve the speech, swallowing and other possible functions affected.

The prognosis of this bacterial infection depends from the amount of Clostridium botulinum that entered the human body, the time when it is diagnosed and on the quality of the supportive treatment. With good ventilation and support therapy, the prognosis is good. If, however, breathing support is required for a long time, complications like respiratory infections, ARDS may occur, and death is possible.

How is Botulism prevented?

It is very important to cook and store the food correctly. Food companies can their food with a pressurized boil to kill the bacterium with high temperatures. Other techniques include high levels of oxygen, high acidity, high ratio of dissolved sugar, or very low levels of moisture.