Staphylococcus aureus (staph) is a bacteria commonly carried on the skin or in the nose of healthy people, possibly in as many as 25-30% of the population, without causing any infection. Sometimes staph can cause an infection of the skin or a more serious infection of the bloodstream or pneumonia.

 

Staph is often divided into 2 categories according to which antibiotics will effectively treat it. If the staph infection can be treated effectively with beta-lactams, such as methicillin, it is often called methicillin susceptible Staphylococcus aureus (MSSA). If methicillin will not be effective, it is called methicillin-resistant Staphylococcus aureus (MRSA). Antibiotics that are often empirically used to treat suspected MRSA while awaiting culture results include trimethoprim-sulfamethoxazole, Minocycline, or Doxycycline. While 25-30% of the population is colonized with staph, approximately 1% is colonized with MRSA.

 

If a person develops a staph infection of the skin, the initial appearance is often a red, tender area on the skin, sometimes mistaken for a spider or insect bite. The appearance might also be a pimple, boil, or abscess. Incising and draining is sometimes done to assist recovery. A culture is sometimes done to determine if staph is the cause of infection and which antibiotic will be most effective. The majority of patients with a staph infection, whether it is MRSA or not, recover successfully with antibiotic pills and do not have a complicated course. Some recover with use of topical antibiotics or no antibiotics. More severe infections may require draining by a surgeon or hospitalization and IV antibiotics. Serious invasive infections can sometimes result in death.

 

Visiting a healthcare provider is important if there is an area of the skin suspicious for infection so there can be proper diagnosis. Remember that staph is not the only cause of skin infection.

 

If infection is diagnosed, follow instructions about treatment and about preventing spread of the infection to others. Keep infected area covered with clean bandages. Bandages can be discarded with regular trash. Wash hands frequently, especially after changing the bandage or touching the infected wound. Do not share personal items, such as towels, razors, clothing, or uniforms that may have had contact with the infected wound or bandage. Wash sheets, towels, and clothes that may have been contaminated. Dry clothing in a hot dryer, rather than air-drying, to help kill bacteria in clothes. A bleach-containing cleaner can be used to sanitize washable surfaces that may have been exposed to bacteria.

 

Those who are well can lessen the risk of a skin infection by keeping hands clean by frequent washing with soap and water, keeping cuts and scrapes clean and covered with a bandage until healed, avoiding contact with bandages or wounds of other people, and not sharing personal items, such as towels or clothing, with anyone. Remember that MRSA infections are more likely to occur if there is an easy entry point into the skin, such as cracks in the skin, abrasions, or an open cut or wound. Avoiding contact with a contaminated object or direct physical contact with MRSA on another person is key to prevention.

 

Additional information about MRSA is available at