Botulinum neurotoxins tract

Botulism is a potent neurotoxin produced from Clostridium botulinum that is an anaerobic, spore-forming bacterium. There are three different types ofbotulism Foodborne botulism occurs when a person ingests a pre-formed toxin that leads to illness within a few hours or days. Foodborne botulism is a public health emergency because the contaminated food may still be available. Infant botulism occurs in a small number of susceptible infants each year who harbor C. botulinum in their intestinal tract. Wound botulism occurs when wounds are infected with C. botulinum that secretes the toxin. Approximately 100 cases of the three types of botulism are reported within the United States each year about 5 percent are wound botulism, 25 percent are foodborne botulism, and a full 70 percent are infant botulism. Death can result from respiratory failure, but those who survive may have fatigue and shortness of breath for years. 

Botulism is most commonly caused by ingestion of a neurotoxin produced by Clostridium botulinum in improperly canned food. Poisoning may also occur after wound contamination with the organism. Infant botulism may occur when spores of the organism germinate and manufacture the toxin in the intestinal tract of infants. Botulinum toxin works by inhibiting ACh release at all cholinergic synapses. 

Although inhalational botulinum intoxication was investigated in other animal species, these studies have not provided specific data on toxin absorption. The behavior of BoNTs in the respiratory tract was only recently investigated. Park and Simpson (2003) studied the properties of pure BoNT/A neurotoxin both in vivo and in vitro using mice and pulmonary cell culture models, respectively. Mean survival times were compared in mice receiving various doses of pure BoNT/A either IN or IP. Pure BoNT/A was found to be a potent intranasal poison, although the toxicity (as determined by mean survival time) associated with IP administration was somewhat higher. Mean survival times in mice were less than 100 (IP) or 600 min (IN) after administration of 0.1 pg pure toxin 75 (IP) or 400 min (IN) for 1 pg toxin and 120 min (IN) for 10 pg toxin (Park and... 

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