November 2009

Botulism is a form of food poisoning caused by eating contaminated food containing a toxin that severely affects the nervous system. It can be very serious, although not contagious. There are two other types, wound botulism and infant botulism. These affect the central nervous system and the muscular system.

Causes of Botulism

Clostridium botulinum, a bacteria found in contaminated or incompletely cooked,
canned foods, is the cause of Botulism. This bacteria produces a powerful poison (toxin) that is absorbed from the digestive tract and spreads throughout the central nervous system. Likely foods to cause botulism include: home-canned vegetables and fruits, fish, meat, undercooked sausage, smoked meats and milk products. With infants under 1 year, raw honey or other uncooked foods may be the cause. The bacteria also may infect a wound and produce the toxin.

Signs and Symptoms of Botulism

Symptoms of Botulism usually appear suddenly 18 to 36 hours after eating contaminated food. They include blurred or double vision, drooping eyelids, dry mouth, slurred speech, swallowing difficulty, vomiting, diarrhea, weakness of the arms and legs. As the condition progresses, paralysis may develop. There is not direct effect on mental abilities and there is no fever associated with Botulism. Symptoms appearing in infants include severe constipation, feeble cry, and the inability to suck.

U.K. researchers linked a protein to the development of mad-cow disease and found a way to reduce it, a discovery that may lead to a treatment for the illness and its human form, according to a report today in PLoS Pathogens.

A team of scientists at the University of Leeds found that the protein, called Glypican-1, boosts abnormal and infectious proteins in the brain called prions, which are known to cause mad-cow disease, or bovine spongiform encephalopathy. When the researchers reduced Glypican-1 in infected mouse cells, abnormal prion levels also declined, they wrote in the online journal.

Glypican-1 may act as a scaffold that brings together the two forms of the prion protein, causing normal prions to mutate into infectious ones, Nigel Hooper, one of the authors, said in a telephone interview.

“It’s bringing the normal prion protein and the infectious molecule together and allowing them to interact,” said Hooper, a professor of biochemistry at the university in northern England. “The infectious molecule will then allow the normal one to convert, setting up a cascade.”

In the mid-1990s, scientists found a possible link between bovine spongiform encephalopathy and a variant of the fatal human illness, Creutzfeldt-Jakob disease, which destroys brain tissue. An estimated 166 people in the U.K. may have died from variant Creutzfeldt-Jakob since 1995, according to the National Creutzfeldt-Jakob Disease Surveillance Unit in Edinburgh.
Infected Animals

People are believed to develop the disease by eating meat from infected animals or after transfusions of infected blood. Early symptoms include depression or psychosis, unsteadiness and involuntary movements. By the time of death, patients become immobile and mute.

Researchers may be able to use the Leeds team’s finding about Glypican-1 to design drugs that disrupt the disease process and treat mad-cow disease or variant CJD, Hooper said. He said his team next plans to study the effect of removing Glypican-1 from mice.

“We’re going into animal models to look at what happens if you take the Glypican-1 out,” Hooper said.
The Wellcome Trust and the U.K.’s Medical Research Council funded the research published today.