A silver bullet for the common cold

Richard Gray, The Sunday Telegraph 

A silver bullet for the common cold

Scientists are hailing a breakthrough that could lead to one of medicine's holy grails - a cure for the common cold.

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Researchers have found they can attach tiny studs of silver to the surface of harmless bacteria, giving them the ability to destroy viruses.



Professor Willy Verstraete, a microbiologist from the University of Ghent, Belgium, who unveiled the findings at a meeting of the Society for Applied Microbiology in London last week, said the bacteria could be incorporated into a nasal spray, water filters and hand washes to prevent viruses from being spread.

"We are using silver nanoparticles, which are extremely small but give a large amount of surface area as they can clump around the virus," he said.

"There are concerns about using such small particles of silver in the human body and what harm it might cause to human health, so we have attached the silver nanoparticles to the surface of a bacterium. It means the particles remain small, but they are not free to roam around the body." The bacteria used, Lactobacillus fermentum, is normally considered to be a "friendly" bacteria that is often found in yogurts and probiotic drinks.

The researchers found that when grown in a solution of silver ions, the bacteria excrete tiny particles of silver, 10,000 times smaller than the width of a human hair, which stud the outside of the cells.

Although the "friendly" bacteria eventually die, they remain intact and the dead cells carrying the silver particles can then be added to solutions to create nasal sprays or hand washes. The researchers also found they could be fixed to other surfaces such as water filters or chopping boards.

Norovirus causes 90 per cent of gastroenteritis cases and is spread through poor hygiene or in contaminated food. Last winter it affected an estimated one million people in England and Wales and forced many hospital wards to be closed. Influenza is a respiratory infection that normally spreads through the air when infected individuals sneeze and it is breathed in by others.

In large amounts, silver can damage the liver, kidneys and lungs. But Prof Verstraete said that by attaching it to the much larger bacteria, it could not pass into other parts of the body.

