What Is MRSA?

  • MRSA (pronounced mersa) is the acronym for Methicillin-resistant Staphylococcus aureus. Staphylococcus aureusis a type of bacteria commonly referred to as Staph.1
  • MRSA is a mutated2 form of Staph bacteria known as a super bug. The super bug status comes from its propensity to cause serious/life-threatening infections and its resistance to antibiotics.

  • Note: Non-MRSA Staph or MSSA (Methicillin-sensitive Staphylococcus aureus) is able to cause the same serious/life-threatening infections as MRSA; however, it doesn’t have the same resistance to antibiotics. See footnotes 1 and 2 below.


[1] Non-MRSA Staph or MSSA (Methicillin-sensitive Staphylococcus aureus) is found on the skin and in the nose in up to one-third of healthy individuals. In years past, non-MRSA Staph would typically develop into superficial skin infections including impetigo. 
-        Deeper skin infections are less common with non-MRSA Staph than with MRSA.
-        Both MRSA and non-MRSA Staph can cause invasive infections.
[2] MRSA bacteria have the mec gene inserted into their DNA. The mec gene privides resistance to the following antibiotics: methicillin, oxacillin, nafcillin, and cephalosporins.