|MadSci Network: Microbiology|
These are all very good questions about C. botulinum and the botulinum neurotoxin (BoNT). The BoNT is destroyed by high temperatures, cooking and/or boiling for 10 minutes is sufficient for toxin inactivation. The foods that are a particular concern for C. botulinum growth are home-canned foods; but, there are still instances where commercial canned foods are associated with botulism. I don't believe that getting toxin into a wound would result in botulism. The reason that I say this is because C. botulinum is an anaerobic bacterium; therefore, it is likely that toxin production takes place under anaerobic conditions - so the chances of the toxin existing in a place where there is an aerobic environment are pretty slim. It is possible for "wound botulism" to exist; however, this usually occurs when a wound (most likely a deep wound where there is an anaerobic environment)is infected with C. botulinum. Once C. bot is in the wound (in vivo), it will then produce BoNT. As a general rule of bacterial toxins, it is likely that a bacteria will only produce toxins when conditions are favorable; i.e. they have a plethora of nutrients, optimal environmental conditions, etc. If the spores are inhaled (and stay as spores), I would guess that a perfectly healthy person, with a competent immune system would not develop signs of botulism because the body will mount an immune response and get rid of the spores. Immunocomprimised persons (extremely young, elderly, AIDS, etc.) may be more susceptible to developing botulism; however, I don't know if there is any evidence specifically documenting this. As far as absorption of the toxin is concerned, I am not sure if it is absorbed into the stomach lining. BoNT is a neurotoxin, so it acts at the neurons. Specifically, it inhibits neurotransmitter release at the neuromuscular junction; resulting in a flaccid paralysis. Other (early) signs of botulism are nausea, diarrhea, visual disturbances, and dry mouth. Later symptoms will include severe respiratory and motor impairment...which can lead to death. I hope that I have satisfied your curosity about botulism; if you would like more information, I highly recommend visiting the Centers for Disease Control and Prevention - they are an excellent source! For information on botulism, go to: http://www.cdc.gov/ncidod/dbmd/diseaseinfo/botulism_g.htm There are a couple of links on that page which may give you more information on incidence, and other details. Good luck! Glynis K. Rutgers University, Food Science Dept.
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