Monday, January 16, 2006
A New Way to Stop Food Bacteria??
Researchers believe they may have found a novel way to disrupt bacteria that cause food poisoning.
The US and UK team have uncovered a previously unrecognised mechanism which bacteria use to escape the body's natural defence responses.
Using this mechanism, the pathogens detect a toxic gas produced by the body and turn it into something that is harmless to evade the onslaught.
Interrupting this might be a way to beat these bacteria, they told Nature.
The team from Georgia Institute of Technology in the US, and the John Innes Centre in the UK looked at harmless strains of the bacterium Escherichia coli.
However, they believe their findings will apply to the more harmful strains of E. coli and its close relation salmonella that cause outbreaks of food poisoning around the world.
These bacteria are usually transmitted to humans through undercooked meat, unwashed vegetables and poor food hygiene and can cause diarrhoea and cramps, which usually get better without help.
However, in those who are particularly vulnerable, such as people with weakened immune systems, the consequences can be particularly serious and may require hospital treatment.
Food poisoning bacteria
About six million people in the UK - 10% of the population - have a case of food poisoning each year. More than half of these are caused by bacteria such as E. coli and salmonella.
There are drugs available to treat complicated infections but the bacteria are learning how to dodge these and are becoming resistant.
Ultimately, Professor Ray Dixon and colleagues hope their discovery will help scientists find new ways to treat such infections.
They found E. coli was able to recognise and rid itself of the poisonous nitric oxide that the body produced to fight infection.
The bacterium has a protein called NorR that once activated controls the expressions of genes. These genes hold the code for an enzyme that removes the nitric oxide, allowing the bug to fend off the body's defences.
Colleague Professor Stephen Spiro explained: "It turns out that the protein NorR contains a single molecule of iron. Our study found that the nitric oxide binds to the iron, which activates the protein.
"If we can interfere with the mechanism, it could lead to better antibiotics and treatments," he said.
Professor Dixon stressed that this would be some years away.
Professor Jay Hinton, head of molecular microbiology at the Institute of Food Research, said:
"Antibiotic resistance is increasing. We do need alternatives.
"What they have found is interesting and unexpected. This, coupled with other work, could lead to new treatments in the future."
He recommended more studies to determine whether the same mechanism was apparent in pathogenic strains of Salmonella, E. coli and other food poisoning bugs.
BBC Health News