Any S. aureus infection can cause the staphylococcal scalded skin syndrome, a cutaneous reaction to exotoxin absorbed into the bloodstream. It can also cause a type of septicaemia called pyaemia. The infection can be life-threatening. Problematically, methicillin-resistant Staphylococcus aureus (MRSA)  has become a major cause of hospital-acquired infections. MRSA has also been recognized with increasing frequency in community-acquired infections. The symptoms of a Staph Infection include a collection of pus, such as a boil or furuncle, or abscess. The area is typically tender or painful and may be reddened or swollen. Coagulase-negative
S. epidermidis, a coagulase-negative staphylococcus species, is a commensal of the skin, but can cause severe infections in immune-suppressed patients and those with central venous catheters. S. saprophyticus, another coagulase-negative species that is part of the normal vaginal flora, is predominantly implicated in uncomplicated lower genitourinary tract infections in young sexually active women. Other staphylococcal species have been implicated in human infections, notably S. lugdunensis, S. schleiferi, and S. caprae. Causes
Staph infections have a multitude of different causes, such as:

Open wounds – This is by far the biggest cause of staph infection. Any open wound, even ones as small as a paper cut, are vulnerable to being infected. Staph bacteria will enter the body through any open wound, so it is important to properly treat, disinfect, and bandage any wounds. Contact with infected persons or surfaces – Staph infections are very contagious when in contact with a person that is already infected.
A person with staph infection is contagious until the bacteria are completely out of their body, and any wounds from the infection are healed. It is common to see the spread of staph in contact sports; i.e. wrestling, through contact in locker rooms, or by sharing any equipment. Weakened immune system – Anyone with a weakened immune system for any reason can be more easily affected by staph bacteria, because their bodies are unable to defend against infectious bacteria as well. Unwashed linens – Staph bacteria are very resistant under harsh conditions, and they will cling to objects where they can create a niche. Unwashed bath towels, blanket, bed sheets, and clothes can create a great environment for these bacteria to grow. This is important to recognize, because every single day people use linens in their daily lives. Infection after surgery – Hospitals are a very common place for staph bacteria to contaminate. This becomes problematic when people are in surgery, because in some cases staph can be introduced to a persons body when an incision is opened. Invasive devices – Medical devices that have any connection to organs to the outside of the body are very problematic, because they allow an easy open pathway into the body. Examples of these devices are; catheters, dialysis tubing, feeding tubes, breathing tubes, etc. Signs and symptoms
Staph infection is typically characterized by redness, pus, swelling, and tenderness in areas of the infection. But, each type of skin infection caused by staph bacteria is different.