· Definition

· Methicillin-Resistant Staphylococcus aureus, also called ‘MRSA’, is a special type of the Staphylococcus aureus bacteria (staph) that has acquired a gene that allows resistance to many antibiotic medications including Methicillin.

· Overview
· Methicillin-Resistant Staphylococcus aureus (MRSA) was first identified as a cause of infections in hospitals and health care facilities. It is thought that the bacteria emerged as a result of environmental pressures from the use of broad coverage and powerful antibiotics in hospitals.

· Methicillin-Resistant Staphylococcus aureus (MRSA) can cause a more severe infection than regular Staph aureus. The bacteria has certain virulence factors, proteins that allow it to produce more aggressive infections.

· Methicillin-Resistant Staphylococcus aureus (MRSA) is an increasingly common cause of skin and soft tissue infections in the United States.

· Methicillin-Resistant Staphylococcus aureus (MRSA) can also cause a more severe form of pneumonia.

· Methicillin-Resistant Staphylococcus aureus (MRSA) infections are estimated to affect almost 100,000 people in the United States each year.

· Methicillin-resistant Staphylococcus aureus (MRSA) is usually suspected when soft tissue and skin infections do not respond to normal antibiotic treatment.

The Community-acquired and community-associated forms of MRSA are the most common cause of skin and tissue infections seen in emergency departments in the United States.

· Methicillin-resistant Staphylococcus aureus (MRSA) is spread by direct physical contact with the bacteria.

· Methicillin-resistant Staphylococcus aureus (MRSA) can colonize( contaminate without causing infection) inside the tip of the nose. People who have MRSA in the tip of their nose may have a higher risk of skin infections.

· Types
· Hospital-acquired Methicillin-resistant Staphylococcus aureus (MRSA)
· Community-acquired Methicillin-resistant Staphylococcus aureus (MRSA)
There are two types of the Community-acquired MRSA called clones USA 300 and USA 400
Outbreaks of skin and soft tissue infections have been most closely linked with USA 300, and outbreaks of fatal infections in children have been linked to USA 400

· Treatment
· Methicillin-resistant Staphylococcus aureus (MRSA) are usually still sensitive to various antibiotics and infections are treated with the antibiotics:
Vancomycin
Linezolid
Bactrim/ Septra
Doxycycline
Minocycline
Clindamycin

References
Emergence of community-acquired methicillin-resistant Staphylococcus aureus USA 300 clone as the predominant cause of skin and soft-tissue infections. Ann Intern Med 144:309, 2006 [PMID: 16520471]