==Virulencia e resistencia a antibióticos==
The ability to form biofilms on plastic devices is a major virulence factor for ''S. epidermidis''. One probable cause is surface proteins that bind blood and extracellular matrix proteins.
Staphylococcus epidermidis produces an extracellular polysaccharide material known as polysaccharide intercellular adhesion (PIA), which is made up of sulfated [[polysaccharide]]. It allows other bacteria to bind to the already existing biofilm, creating a multilayer biofilm.
Such biofilms decrease the metabolic activity of bacteria within them. This decreased metabolism, in combination with impaired diffusion of antibiotics, makes it difficult for antibiotics to effectively clear this type of infection.<ref name="Salyers" />
''S. epidermidis'' strains are often resistant to antibiotics, including [[penicillin]], [[amoxicillin]], and [[methicillin]]. Resistant organisms are most commonly found in the intestine, but organisms living freely on the skin can also become resistant due to routine exposure to antibiotics secreted in sweat.
== Enfermidades ==