👉 Staphylococcus aureus is a Gram-negative, rod-shaped bacterium that can cause infections in various parts of the body. It is commonly found in the skin and mucous membranes, but it can also be found in other tissues and fluids such as blood, spinal fluid, and tears. A staphylococcus aureus infection occurs when bacteria enter the body through a cut or wound, where they cause an inflammation and damage to the lining of the skin or mucous membranes.