May also be called: Methicillin-Resistant Staphylococcus Aureus; Oxacillin-Resistant Staphylococcus Aureus; ORSA

MRSA stands for methicillin-resistant Staphylococcus aureus. Staph is the shortened name for Staphylococcus (staf-uh-low-KAH-kus), a type of bacteria. MRSA is a strain of staph bacteria that resists certain medicines that usually treat staph infections.

More to Know

Many strains of staph bacteria are quite common, and most people have staph bacteria living harmlessly on their skin or in their noses. Staph bacteria that enter the body through a cut, scrape, or rash can cause minor skin infections. Most of these heal on their own if the wound is kept clean and bandaged, but sometimes antibiotics are needed.

What makes the MRSA strain different from other staph bacteria is its resistance to the antibiotics that usually treat staph infections. When bacteria are resistant to antibiotics, they are harder to kill.

MRSA infections often develop around open sores, like cuts, scrapes, or bites, but also can develop on intact skin. Red, swollen, painful bumps appear that sometimes weep (leak) fluid or pus. Some people also develop a fever.

In more serious cases, the infection can spread to the blood, lungs, bones, joints, or other parts of the body. MRSA also can cause infections like pneumonia. Fortunately, complications like these are not common in healthy people.

MRSA infections require different medicines and approaches to treatment than other staph infections do. Doctors may prescribe oral antibiotics to help treat a MRSA infection. More severe infections might need IV (intravenous) antibiotics, given in a hospital. If there is a collection of pus or fluid, called an abscess, it may require drainage.

Keep in Mind

Most MRSA infections are treated without long-term issues. Many such infections can be prevented by washing hands well and often, keeping cuts and scrapes clean and covered with a bandage, not sharing personal items (like razors, towels, or uniforms), and making sure to take the full amount of any antibiotics as prescribed.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.