MRSA is the acronym for methicillin-resistant Staphylococcus aureus, a type of staph bacteria that is resistant to antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin.

Staphylococcus aureus, often referred to simply as "staph," is a bacteria commonly carried on the skin or in the nose of healthy people. Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose with staph bacteria. Sometimes, staph can cause an infection. Staph bacteria are one of the most common causes of skin infections in the United States. Most of these skin infections are minor (such as pimples and boils) and can be effectively treated by drainage of pus with or without antibiotics (also known as antimicrobials or antibacterials). However, staph bacteria also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia).

While 25% to 30% of the population is colonized with staph, approximately 1% is colonized with MRSA.

Colonization = organism is on or in the body but not causing disease.
Infection = organism is present and causing signs and symptoms of disease.

Most MRSA infections are skin infections that may appear as pustules or boils that often are red, swollen, painful, or have pus or other drainage. These skin infections commonly occur at sites of visible skin trauma, such as cuts and abrasions, and areas of the body covered by hair (e.g., back of neck, groin, buttock, armpit, beard area of men).

Almost all MRSA skin infections can be effectively treated by drainage of pus with or without antibiotics (also known as antimicrobials or antibiotics). More serious infections, such as pneumonia, bloodstream infections, or bone infections, are very rare in healthy people who get MRSA skin infections.

These pictures of actual MRSA infections can help visitors determine whether they may be exhibiting symptoms of MRSA. Of course, only trained medical professionals can definitively diagnose MRSA. If you suspect you may have MRSA infection, please contact your physician.

S. aureus bacteria are amongst the populations of bacteria normally found existing on ones skin surface. However, over time, various populations of these bacteria have become resistant to a number of antibiotics, which makes them very difficult to fight when attempting to treat infections where MRSA bacteria are the responsible pathogens. These antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin.

Staph infections, including MRSA, occur most frequently among persons in hospitals and healthcare facilities such as nursing homes and dialysis centers, who have weakened immune systems, however, the manifestation of MRSA infections that are acquired by otherwise healthy individuals, who have not been recently hospitalized, or had a medical procedure such as dialysis, or surgery, first began to emerged in the mid- to late-1990's. These infections in the community are usually manifested as minor skin infections such as pimples and boils. Transmission of MRSA has been reported most frequently in certain populations, e.g., children, sports participants, or jail inmates.