Scientists chance upon protein that can kill E. coli

Scientists at a British university have chanced up a protein that can kill the E. coli bacterium, known to cause serious food poisoning in humans.

The protein Colicin N is found inside the Escherichia coli itself, and kills competing bacterium in a very efficient way.

As part of their investigations, researchers at Newcastle University divided the protein into three parts: a receptor, which helps the protein lock-on to the bacterium; a toxic part that punches holes in the membrane of the bacterium to kill it; and a "tail-like" part.

The "tail" was thought to help the protein sneak into the cell but assumed to be harmless to the bacterium itself.

According to the researchers, they wanted to see what effect each part of the protein would have on E.coli bacteria. Amazingly when they introduced the translocation tail into the environment of the bacteria, it killed them.

Chris Johnson, a researcher who made the key discovery, said: "When I saw what had happened I didn't believe it. So we repeated it several times and the same thing happened, the bacteria died. This was certainly a result that we weren't expecting. We don't really know how this is all working so we will be looking at this in much more detail but it looks promising."

The research team at Newcastle described their findings in a paper published in the journal Molecular Microbiology this week.

Professor of structural biochemistry at Newcastle University's Centre for Bacterial Cell Biology, Jeremy Lakey, who led the research team, said: "It will be relatively easy to make new antibiotics out of it."

He, however, added that the research was still in its early stages.

"It's an early stage basic discovery. It kills bacteria by a new and as yet unknown mechanism, so we need to do a lot more work to discover exactly what is happening here and whether it could be used for new drugs. But it is unlike anything I have seen before and one of the most exciting things I have seen in 30 years of research on antibacterials," he said.

The finding means a whole new class of antibiotics to help fight Escherichia coli.

Antibiotics have saved millions of lives across the world, but recently several experts have warned that over use has resulted into the bacteria developing immunity and the drugs becoming ineffective.

The discovery shows promise in combating an increasingly important class of antibiotic resistant infections caused by E. coli.