Researchers develop viruses to kill off superbugs

Published on Monday 2 March 2009 21:21

A VIRUS that knocks out bacterial defence systems was unveiled yesterday as the latest weapon in the fight against drug-resistant superbugs.

Researchers in the United States engineered viruses that normally prey on bacteria to attack an "Achille's heel" in resistant bugs.

The "bacteriophages" were programmed to target a DNA repair system that allows the bacteria to survive antibiotics.

Used alongside the drugs, the viruses wipe out bacterial defences and prevent resistance from developing.

Dr Timothy Lu, of the Massachusetts Institute of Technology in Boston, who led the research, said: "There are a lot of targets to go after, but people haven't been able to find the drugs.

"It's much easier to modify phages than to invent a new drug."

The researchers tested the viruses with three major classes of antibiotics, called quinolones, beta-lactams and aminoglyclosides.

In mice infected with bacteria, those treated with both antibiotics and the engineered viruses had a survival rate of 80 per cent.

This compared with a 50 per cent survival rate for mice treated with natural bacteriophages and antibiotics, and just 20 per cent for those treated only with antibiotics.

"This work lays the groundwork for the development of a library of bacteriophages, each designed to attack different bacterial targets," said Dr Lu.

The research is reported in the journal Proceedings of the National Academy of Sciences.

In 2007, Dr Lu and his colleague, Professor James Collins, created an engineered virus that could destroy surface "biofilms" of harmful bacteria on industrial and medical devices.

They could be used in food processing plants, hospitals or other settings where disease-causing bacteria may accumulate.