Clostridium botulinum is a rod-shaped bacterium that reproduces by forming spores. There are four different subgroups, all of which produce what is known as botulinum toxin. This can also be pathogenic (disease-causing) to humans and cause poisoning.
What is Clostridium botulinum?
Clostridium botulinum is classified as a gram-positive (responsive to the Gram stain method), rod-shaped bacteria. It is spore-forming and anaerobic, so it does not use oxygen for its life processes. There are different groups of the bacterium, each of which produces different types of botulinum toxin. Of the twelve toxin types, five are pathogenic to humans. Botulinum toxin acts on the nervous system and is one of the most potent toxins known. Its effect is based on the inhibition of neurotransmitters (messenger substances) between nerves and muscles, resulting in paralysis. When the toxin is neutralized, these regress.
Occurrence, distribution and properties
The bacterium Clostridium botulinum is rod-shaped, gram-positive, and spore-forming. It has an anerobic lifestyle but is quite insensitive to oxygen. In total, there are four different groups, which differ significantly from each other biochemically. However, all of them form botulinum toxin, of which there are nine different types (A,B,C1,C2,D,E,F,G,H). Types A,B,F,E and H are pathogenic to humans. Group 1 of Clostridium botulinum with toxins A,B and F reproduces optimally at a temperature between 35 and 40 degrees Celsius, the spores are heat resistant up to 112 degrees. Group 2 with toxins B,E and F has its optimal temperature between 18 and 25 degrees Celsius and the spores are heat resistant up to 80 degrees. Toxin types A and B have a pathogenic effect on humans and are transmitted mainly through home-made canned foods containing meat, fish, vegetables and fruits, as well as through processed dishes containing pork products. Types E and F of botulinum toxin are transmitted to humans through fish and marine products and meat. They cause severe food poisoning, but can also multiply as so-called wound botulism in dead tissue or as infant botulism in the intestines of infants. Clostridium botulinum also multiplies very rapidly in animal carcasses and sometimes in plant material containing protein components. The toxin can be rendered harmless by heating. The temperature must be 100 degrees Celsius for at least five minutes.
Meaning and function
Botulinum toxin A, produced by Clostridium botulinum, is colloquially known as “Botox” and is approved for medical and cosmetic use. It causes muscle paralysis. This property is used in the cosmetic sector for the treatment of wrinkles in the facial area by means of injections. The effect of Botox injections lasts about three to six months, and the wrinkles are no longer visible. In the medical sector, botulinum toxin A is used for the treatment of spasms and spastic paralysis. The toxin is also used in medicinal form for excessive sweating or salivation. When treated with botulinum toxin, side effects such as infection, bruising, or visual disturbances may occur with local injections.
Diseases and medical conditions
The toxin of Clostridum botulinum is one of the most potent poisons of all. Spores can germinate and produce toxin, especially in airtight canned foods containing meat, fish, vegetables, and fruits. This particularly affects underheated and homemade canned foods. In the production of food, the multiplication of the bacterium is prevented by heat sterilization or also by pickling. Poisoning with botulinum toxin is also called botulism. It is a notifiable poisoning that occurs within two hours to 14 days after consumption of the toxin-containing food. The shorter this incubation period, the more severe the course of the disease. The effect of the toxin is based on blocking the transmission of signals from nerve cells to muscles. As a rule, the eye muscles are affected first, blurred vision and double vision occur, the eyes close and the pupils dilate. As it progresses, the muscles of the lips, tongue and palate are affected. Severe dry mouth, swallowing and speech disorders occur.Symptoms typically present without fever. In a severe course, paralysis spreads to the muscles of the internal organs. Diarrhea, vomiting, constipation, and abdominal cramps result. Death occurs by suffocation if the respiratory muscles are paralyzed or by cardiac arrest if the heart muscle is paralyzed. The toderate is highest in botulinum toxin type A poisoning, followed by type E and type B. Treatment is primarily by administration of antidotes, which reduces mortality from over 90 percent to about 15 percent. The disappearance of paralysis often takes months. In infant botulism, poisoning results from the ingestion of spores through the intestine. Up to about one year of age, the body produces too little stomach acid to kill the spores of Clostridium botulinum ingested with food. These then germinate in the intestine and lead to botulism. For this reason, consumption of honey is discouraged in children under one year of age because it may contain spores of the bacterium.
