Killer dyes that can wipe out bacteria could help solve the superbug problems faced by surgical patients, scientists heard today (Wednesday 10 September 2008) at the Society for General Microbiology's Autumn meeting being held this week at Trinity College, Dublin.
"We showed that 99% of the potentially dangerous Staphylococcus aureus bacteria in infected wounds can be killed using a green dye that gives off toxic molecules when it is activated by near-infrared light," said Dr Ghada Omar from University College London, UK.
Near-infrared light is commonly used in fibre-optics and telecommunications because it passes through glass easily. Researchers have now discovered that it can be used alongside a dye to kill bacteria that infect wounds and burns. The dye used, called indocyanine green, is harmless to humans and inactive in the dark. However, it gives off toxic molecules that rapidly kill the bacteria when it is triggered by the right light wavelengths.
"The chemicals produced when the dye is activated harm the bacteria in such a wide variety of ways that it is unlikely bacteria could ever develop resistance to the treatment," said Dr Omar. This makes it ideal - and possibly the only option - for treating infections with multiple drug resistant bacteria, including MRSA."
Infected wounds are a major problem for thousands of hospital patients every year, and up to 9% of hospital acquired infections occur during surgery, contributing to 77% of deaths from surgical operations. These infections increase the length of time patients must remain in hospital by an average of 10 days, increasing the cost to the NHS by up to two and a half times to as much as £2,400 per patient.