A staph infection is a type of bacterial infection that commonly occurs at sites of visible skin trauma (such as cuts and abrasions) and areas of the body covered by hair. One of the most common symptoms is a single red bump (or cluster of bumps); the affected site may also be swollen and painful. Treatment typically involves antibiotics, warm compresses, and draining of the infected area.
A staph infection is caused by Staphylococcus bacteria. Staphylococci are gram-positive bacteria commonly found on the skin, in the nose, and within the mucous membranes of healthy people. Most of the time, they do not cause problems. However, the bacteria can sometimes get into the body and cause an infection.
Staphylococci are one of the most common causes of skin infections in the United States. They can also cause food poisoning, toxic shock syndrome, or serious infections within virtually any organ of the body. Some examples include infections within the lungs (pneumonia), bone (osteomyelitis), and soft tissue (cellulitis) (see Staph Infection Types).
There are several dozen strains of Staphylococcus bacteria. Only a couple are known to cause infections in humans. Staphylococcus aureus (S. aureus) is the most common cause of staph infections (see Staph Infection Causes).
Probably the most well-known Staphylococcus bacteria are methicillin-resistant Staphylococcus aureus, or MRSA for short. MRSA is a less common, but potentially more serious, strain of staph. It is resistant to antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics, such as oxacillin, penicillin, and amoxicillin (Amoxil®).
Over the past several decades, MRSA has gone from being a controllable cause of staph infections to a serious public health concern.
(We have a series of articles that specifically talk about MRSA. Click MRSA (Methicillin-Resistant Staphylococcus Aureus) Infection to read more.)