Staphylococcus aureus is the most common cause of staph infections. Its is a spherical bacterium, frequently part of the skin flora found in the nose and on skin. About 1 in 5 people are long-term carriers of S. aureus. This bacterium can cause a range of illnesses from minor skin infections, such as pimples, impetigo, boils, cellulitis folliculitis, carbuncles, scalded skin syndrome and abscesses, to life-threatening diseases such as pneumonia, meningitis, osteomyelitis, endocarditis, toxic shock syndrome (TSS), and septicemia. Its incidence is from skin, soft tissue, respiratory, bone, joint, endovascular to wound infections. As one of the five most common causes of nosocomial infections,  S.Aureus often causing postsurgical wound infections. Nosocomial infections itself are infections which are a result of treatment in a hospital or a healthcare service unit, but secondary to the patient’s original condition. Infections are considered nosocomial if they first appear 48 hours or more after hospital admission or within 30 days after discharge.

Spread of S. aureus (including MRSA) is through human-to-human contact, although recently some vets have discovered that the infection can be spread through pets, with environmental contamination thought to play a relatively unimportant part. Appropriate hand washing are effective in preventing the transmission of S. aureus. The use of disposable aprons and gloves by staff reduces skin-to-skin contact and therefore further reduces the risk of transmission.