Staphylococcus aureus
Staphylococcus aureus (also S. aureus, from the Greek σταφυλόκοκκος, “grape-cluster berry”, Latin aureus, “golden”) is a Gram-positive, round shaped bacterium appearing in grape-like clusters, often living on the skin or in the nose of a person, as well as in the lower reproductive tract of women. It is anaerobic, which means that it can grow without an oxygen atmosphere. Although S. aureus lives as a normal inhabitant on the human body, it can become an opportunistic pathogen. This means that if people have a weakened immune system, they can become ill from S. aureus infections. It causes a variety of illnesses, from skin and joint infections to respiratory infections, and food poisoning. Some of the diseases caused can be life threatening, like meningitis, bacteremia and toxic shock syndrome. S. aureus is a very common cause of infection in hospitals.