MRSA: Methicillin Resistant Staphylococcus Aureus

A ‘super-bug’ and used as marker of hospital hygiene. It is bacteria of the Staphylococcus aureus group that are resistant to many antibiotics are usually used against it. Traditionally MRSA stood for methicillin resistance. But the term increasingly refers to a multi- or multiple-drug resistant group

MRSA is usually found in hospitals and institutions such as nursing homes, where it is known as hospital-acquired MRSA (HA-MRSA). Less commonly, MRSA is found in the general community (CA-MRSA)

There are three main reservoirs: staff, patients and inanimate objects such as beds, linen and utensils. By far the most important reservoir is patients, who may be colonised with MRSA without evidence of infection. The usual sites of colonisation with MRSA are:

Nostrils
Groin
Axilla
Wounds.

Many health professionals (and public) are colonised with MRSA but do not develop infection. Once colonisation has been present for more than three months, it becomes much more difficult to clear. Patients, however, have a 30–60% risk of infection following colonisation

Most MRSA infections occur in wounds (e.g. surgical wounds), skin (e.g. intravenous access sites), or in the bloodstream (sepsis)

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MRSA: Methicillin Resistant Staphylococcus Aureus

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