Methicillin-resistant Staphylococcus aureus, or MRSA, is a bacterial strain that is resistant to the antibiotic methicillin. It occurs on the skin but can infect organs, the blood stream or surgical wounds. The severity of the infection depends on its location and host defenses, according to WebMD.
Staphylococcus aureus is a common bacterium found on humans and is usually responsive to antibiotics, but due to unnecessary antibiotic use, some staphylococcal bacteria became resistant to antibiotics. MRSA is difficult to treat due to this, notes Mayo Clinic. It is most prevalent in hospitalized patients, particularly those with weak immune systems, nursing home residents and those with an indwelling device, such as a catheter or intravenous line. Community-acquired MRSA is most often found in individuals who live in crowded quarters, such as military recruits and inmates, or those who have skin-to-skin contact playing sports. It begins as small, red, pimple-like marks but can rapidly turn into painful boils.
MRSA bacteria are carried by approximately 2 percent of the population although the majority of those people are not infected. MRSA skin infections are spread by direct and indirect contact. They are usually treated by incision and drainage of the abscess. Invasive infections are treated with intravenous antibiotics, explains WebMD, but the number of antibiotics that are effective is declining.