Magic bullet targets and kills MRSA at the speed of light

Published on Tuesday 31 March 2009 23:10

SCIENTISTS have created a light-activated "magic bullet" that targets and kills MRSA.

Researchers attached a light-sensitive antimicrobial drug to a protein fragment, or peptide, which latches on to a molecule on the surface of the superbug bacterium.

In this way the methicillin-resistant Staphylococcus aureus (MRSA) bugs are targeted, while human cells are left alone.

The antimicrobial agent, tin chlorin e6, releases destructive molecules that kill the bacteria when exposed to light of the right wavelength.

In tests, the therapy killed 99.97 per cent of ten million MRSA cells and proved 1,000 times more effective than tin chlorin e6 without the targeting peptide. The killing mechanism used makes it very unlikely that bacteria would develop resistance against the treatment, say the scientists.

Linda Dekker, of University College London, will present the findings today at the Society for General Microbiology's annual meeting in Harrogate.

"The results from laboratory studies are very encouraging and indicate that this technique might be effective at treating tropical infections, such as wound and burn infections," said Ms Dekker.

"This work will require in vivo (outside the laboratory] trials before it can be used. Due to the growing resistance of many organisms to antibiotics, this approach may be the only one available for use against microbes resistant to all known antibiotics."