Methicillin-resistant Staphylococcus aureus most commonly infects the skin, causing painful raised lesions that are often mistaken for spider bites. Initially infection forms a boil-like lesion, but then may spread over wide areas of the skin causing swelling, redness, and pain. If treatment is delayed the bacteria may invade the blood stream and can cause fatal septic shock. In the hospital MRSA can also enter the blood stream through intravenous catheters and infect heart valves. This bacteria can also contaminate respirators leading to MRSA pneumonia.


Many antibiotics that were effective for Staphylococcus such as cephalosporins and oxacillin do not kill MRSA. The drug of choice is vancomycin. Unfortunately this drug can only be given intravenously. Many forms of community-acquired MRSA are also susceptible to trimethoprim-sulfa (also called bactrim or septra). At the present time there is no vaccine available for the prevention of MRSA.


The wide use and misuse of antibiotics has resulted in selection of two types of MRSA in Florida. The form found in hospitals (hospital-acquired) is highly antibiotic-resistant and is only susceptible to vancomycin and several newer more expensive antibiotics (linezolid and daptomycin). The second form is found in the community (Community-acquired MRSA). This form spreads from person to person in locker rooms and develops after an athlete suffers a cut. The community-acquired form is susceptible to a wider range of antibiotics including vancomycin, doxycycline and trimethoprim sulfa. Football, as well as other contact sports, are popular in Florida. These sports often cause cuts that allow MRSA to invade the skin and cause infection. Our warm climate also causes sweating that softens the skin and makes it more susceptible to bacterial invasion. Many high schools and colleges in our state are having or will have outbreaks of this potentially dangerous infection.


To prevent the spread of MRSA to others, hospital personnel wear gloves when touching infected patients, and often wear gowns and masks. Cuts, scrapes, and wounds should be carefully washed and then covered until they heal. These actions prevent MRSA from attacking the wound. Hands need to be washed regularly with soap and water. Everyone should avoid sharing personal items, such as towels, clothing, cosmetics and razors. All clothes and bedding should be frequently washed with water and detergents.

Prepared by:

Lennox K. Archibald, MBBS, MD, FRCP (Lond), FRCP (Glasg.), DTM&H
Hospital Epidemiologist
Division of Infectious Diseases
University of Florida College of Medicine

Frederick Southwick, M.D.
Professor of Medicine and Chief of Infectious Diseases
University of Florida College of Medicine

For more information see

Infectious Diseases in 30 Days, McGraw-Hill, 2003, pg 2-6; 319-326