Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacteria that is resistant to certain antibiotics. These antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin. Staph are common bacteria that can live on our bodies. Healthy people can carry staph without being infected by it. In fact, 25-30% of us have staph bacteria in our noses.
But staph can be a problem if it manages to get into the body. Once inside the body, it can cause an infection. Staph is one of the most common causes of skin infections in the U.S.