A plant compound has been discovered that helps antibiotics fight the troublesome Staphylococcus infection. The substance taken from the Chilean avocado plant is effective in combating Staphylococcus aureus - commonly called yellow or golden staph - when used alongside antibiotics.

Staphylococcus aureus is the biggest source of infection following an operation.

The compound was found by Danish PhD researcher Jes Gitz Holler.

The University of Copenhagen student explains, "Resistant bacteria have an efflux pump in their bacterial membrane that efficiently pumps out antibiotics as soon as they have gained access. The identified natural substance inhibits the pumping action, so that the bacteria's defence mechanisms are broken down and the antibiotic treatment allowed to work."

The discovery is particularly welcome as virulent infections are becoming more common in hospitals and some strains are showing signs of not responding to treatment.

The rainforest plant, whose leaves used by Chile's indigenous Mapuche people to treat wounds, was collected by Jes Gitz Holler. His report appears in the Journal of Antimicrobial Chemotherapy.

The effectiveness of antibiotics is measured by Minimum Inhibitory Concentration or MIC values, which show the lowest concentration of antimicrobial required to slow the growth of the micro organism. The avocado compound reduces the MIC value a minimum of eight times.

The aim is to improve the strength of the compound using synthetic chemistry and to eventually create a drug that will fight the resistant strains. In addition, the lab work will help protect the plant and if a drug is developed and sold, the Mapuche people will benefit, as an agreement has been signed with them for helping obtain the compound.

Staphylococcus aureus has been a major issue for hospitals around the world for more than 50 years. As well as casing would infections, it can lead to food poisoning, abscesses and major infections that can prove fatal.

There is currently little commercial interest in finding new antibiotics, as the drug industry believes there is not enough profit to be gained.

Finding effective plant compounds is one way that treatment can be advanced, according to Jes Gitz Holler.