Scientists in Northern Ireland say they have made a breakthrough which they hope will kill the superbug MRSA.
A gel is being used in the research
The bug not only costs lives - the health service spends thousands of pounds on trying to keep it out of hospitals.
Pharmacists at Queen's University in Belfast say they have developed a new way of killing MRSA.
It is due to be tried out on patients as early as next year.
For many years antibiotics have been used to kill bacteria, but bugs like MRSA are resistant to antibiotics, so now scientists are turning the clock back.
Dr Ryan Donnelly of Queen's School of Pharmacy
Dr Ryan Donnelly, of Queen's School of Pharmacy, said: "The ability of light to kill bacteria was first discovered about 100 ago, but because of the antibiotic era it was largely forgotten.
"It is only recently with the emergence of antibiotic-resistant bacteria that this has come to the fore again and many different groups involved in treating the likes of MRSA are trying to use this technology now."
A new gel is used to put a drug where it is needed.
Dr Paul McCarron, also of Queen's, said: "I saw my son, Niall, who was playing with kiddies' slime and I was just looking at the way it flowed between his fingers.
Dr Paul McCarron got inspiration from kiddies' play slime
"I thought it had the correct flow properties, to press into a leg ulcer for example. In other words, it can be pressed in and it will slowly flow to fill the cavity.
"More importantly, whenever you remove it, it can be removed all in one go."
The gel deposits a drug into the wound or ulcer and then it is lifted out, leaving behind the drug.
The drug makes MRSA and other bugs sensitive to light - much more so than the human cells, so when a powerful light is shone on the wound, it is the bugs like MRSA that will be killed.
Dr Donnelly said: "Certainly, from the work we have done so far, we would like to think that this technology could be successful in eradicating MRSA from wounds and burns in patients in the clinical situation."
BBC Northern Ireland health correspondent Dot Kirby said tests were due to begin on patients in Belfast City Hospital in the next 12 to 18 weeks.
"If this technique does work, its cost is likely to be small," she said.
"The drugs are cheap and the light units are expected to cost around £15,000. Each light unit could serve a whole hospital."