In adults, bacteria colonization is present on normal intact skin, with the estimated amounts being several million. There may be a 1000 different bacterial species residing on the skin. Skin develops an ecosystem colonized with bacterial, viruses, fungi, and mites referred to the skin microbiome. The acid nature of the skin keeps the resident bacterial attached to the skin and the consistent turnover or shedding of the outer layer of skin keeps the bacterial numbers fairly constant. Medical conditions (Diabetes; chronic renal failure; dermatitis; obesity); Certain medications (anti-inflammatories, prednisone; chemotherapy; immunosuppression drugs), age, geographic location of residence in terms of hot and cold climates and the products used on the skin and moisture affect the type and amount of bacteria present on the skin.
The identification of biofilms in wounds has complicated the diagnosis and treatment of wound infections. A biofilm is a population or community of bacterial living in organized structures at the liquid interface. Bacteria within a biofilm live in microcolonies that are encapsulated in a matrix composed of an extracellular polymeric substance separated by open waster channels. The biofilm environment provides physical protection to bacterial and makes it difficult for antibiotics to penetrate and treat the infection.
Appropriate hand washing, disinfecting and hand drying with disposable paper towels are the most effective ways of removing bacteria from the skin. Quantities of bacteria experience a temporary decrease after hand washing, but are back to their usual amount within 2-4 hours. Skin and its outer colonies of bacteria have a normally symbiotic relationship, but anything, externally or internally, can disrupt the delicate relationship. When a wound occurs in the skin, the potential for infection exists. Probably the most important factor in preventing infection is the immune system of the individual. Even intact immune systems can be overwhelmed if there are large amounts or very virulent bacterial introduced.