Diagnosis and Treatment of Staphylococcus aureus - Minnesota Dept. of Health

Diagnosis and Treatment of Staphylococcus aureus

S. aureus is part of the normal human flora (bacteria that normally reside in or on humans) and does not usually cause infection. When bacteria are living on or in the human body, but are not causing infection, it is called “colonization.” Humans are most often colonized with S. aureus in their noses and it is also found on the skin and other body sites. Over time, 20% of the population will almost always be colonized with S. aureus, 60% of the population will be colonized with S. aureus off and on, and another 20% are almost never colonized with S. aureus.

On this page:


  • Definitive diagnosis of S. aureus infection is made by obtaining a culture from the area of suspected infection.

  • Suspect diagnosis is based on patient symptoms and the health care provider’s evaluation.


  • Some skin infections do not require treatment.

  • Others skin infections may require incision and drainage of the infected site and/or antibiotic treatment.

  • If your doctor or health care provider prescribes antibiotics, it is important that you take all the doses that are prescribed.

  • If your infection does not get better after treatment, contact your health care provider.

MRSA treatment:

  • MRSA bacteria can be resistant to many types of antibiotics.

  • It is important to make sure that a culture from the infected area is obtained.

  • Laboratories can test to find out which antibiotics will work to kill the bacteria.

  • Testing the culture will ensure that the correct antibiotic is given for treatment of the infection.

Updated Friday, 28-Jan-2022 12:38:26 CST