The search for a weapon to combat antibiotic-resistant superbugs has gone 1,000 years into the past — to an Anglo-Saxon treatment for eye infections.
Scientists recreating an "eye salve" recipe found in one of the world's earliest existing medical textbooks said they were astonished to see it almost completely kill methicillin-resistant Staphylococcus aureus, a "superbug" otherwise known as MRSA that is resistant to several types of antibiotics.
Researchers found the remedy in an old British Library manuscript known as Bald's Leechbook, a manuscript of instructions for treating various ailments.
The book's eye treatment for a stye included garlic, wine, onions or leeks, and bile from a cow's stomach, all prepared in a brass vessel.
Christina Lee, a University of Nottingham expert on Anglo-Saxon times and society, successfully translated the text, which contained some ambiguities.
"We chose this recipe in Bald's Leechbook because it contains ingredients such as garlic that are currently investigated by other researchers on their potential antibiotic effectiveness," said Lee.
Biologists at the university's Centre for Biomolecular Sciences recreated a 10th-century potion for eye infections followed her translated recipe as faithfully as they could to create the salve for testing against various bacteria.
"The Bald gives very precise instructions for the ratio of different ingredients and for the way they should be combined before use, so we tried to follow that as closely as possible," said microbiologist Freya Harrison.
The researchers were surprised by their lab experiments, which showed the Bald's eye salve to be a potent antibiotic against Staphylococcal infections.
"We were going from a mature, established population of a few billion [bacteria] cells, all stuck together in this highly protected biofilm coat, to really just a few thousand cells left alive," Harrison explained. "This is a massive, massive killing ability."
The researchers said they believe the antibiotic effect is the result of the combination of elements in the recipe rather than any single ingredient. The salve also apparently remains potent for long periods of time if kept bottled in a refrigerator.
"I still can't quite believe how well this 1,000-year-old antibiotic actually seems to be working," Harrison said. "When we got the first results we were just utterly dumbfounded. We did not see this coming at all."
The researchers said they will present their findings at the annual conference of the Society for General Microbiology, held this week in Birmingham, England.
