S. aureus is common gram-positive bacteria which may cause severe infections in clinical practices.In nature, bacteria normally exist in two states: planktonic or biofilms. Unlike planktonic cell, which are free floating microbes in suspension, cells within a biofilm adhere to the surface of soft tissues and implanted medical devices such as, hips and knees.Following bacterial initial attachment, the bacteria will secrete an extracellular polysaccharide matrix to protect themselves as they gather the accumulated nutrients from the surrounding aqueous environment required for biofilm survival.As a result, the bacteria within the biofilms are approximately 10 to 1000 times harder to be killed by antibiotics.