The study, conducted by the Rutgers University in the US, showed the two genes, named copB and copL, in some strains of S. aureus bacteria protect the germs from copper.
The genes may promote the survival of S. aureus in settings, such as in hospitals, that could lead to infections or they may lead to S. aureus strains with higher copper resistance.
Recently, hospitals began using it against bacteria found on medical instruments and other surfaces. It has also been used for thousands of years to sterilise wounds and drinking water.
But the two newly discovered genes encode proteins that help remove copper from S. aureus cells and prevent it from entering.
The findings, published in the Journal of Biological Chemistry, revealed that some strains of S. aureus have newly acquired genes embedded in their genome in pieces of DNA called transposons.
Transposons aid in the spread of genes that can give rise to bacteria that are resistant to antibiotics and more likely to cause disease. The newly discovered genes are encoded within a transposon, said the study.