Staphylococcus aureus (S. aureus) is a common bacteria (germ). This bacteria is present on the skin and in the nose of many people. For most healthy people this bacteria does not cause a problem. This bacteria can enter the body and cause infection. The bacteria is most likely to enter the body if:
There is an open wound in the skin or,
The person has a suppressed immune system.
S. aureus can cause serious infections of skin, blood stream, bone, lung, and other sites.
MRSA stands for Methicillin Resistant Staphylococcus Aureus. Methicillin is a type of antibiotic designed to treat S. aureus. Over time some types of S. aureus have become resistant to methicillin. S. aureus that are resistant to methicillin are also resistant to several related antibiotics commonly used for treatment of S. aureus. Another type of antibiotic will need to be used to treat the S. aureus. MRSA has become increasingly common. MRSA was initially found mostly in hospitals, but now is also found in the community. MRSA is more difficult to treat than other S. aureus, because of its resistance to antibiotics.
Colonization Versus Infection
Colonization means the MRSA is present in or on the body but is not causing illness. Healthy people may carry the bacteria causing MRSA without becoming ill. Infection means the MRSA is present in or on the body and is causing illness. Symptoms of MRSA may vary depending on the part of the body that is infected. Infection can commonly occur in the skin, but can also occur in any organ in the body.