A wound culture is a test used to identify bacteria, viruses, fungi, and other germs that may exist within a wound. To conduct a wound culture, a health professional takes a fluid or tissue sample from the wound in question and places it in a container containing a medium, or growth culture. A medium is a nutrient-rich substance used to promote growth; any germs present in the fluid or tissue sample will almost certainly grow and multiply. If anything does grow in the container, the presence of some form of germ has been confirmed and further tests can be performed for the purpose of identification. If nothing grows, on the other hand, one can reasonably assume that there are no bacteria, fungi, or viruses growing in the wound.
A specific kind of wound culture such as a fungal culture may be used if the cause of a given infection is suspected or if most other alternative possibilities have been ruled out. A viral culture, for example, uses a medium full of cells that a virus can infect in order to grow and multiply. The infected cells change in various ways, allowing health professionals to confirm the presence of a virus in the culture. Some kinds of cultures may grow quickly, allowing for rapid identification, while others may require several weeks of growth time before they can be properly identified.
The primary purpose of a wound culture is to identify the specific agent causing an infection so a proper treatment can be administered to prevent further damage from infection. In some cases, simple topical antibiotic or antifungal medications may be adequate to remove the infection and to allow the wound to heal properly. In other cases, however, the wound culture reveals the presence of a particularly resilient infectious agent that must be treated through other means. Serious infections can spread from the wound to the rest of the body and cause serious problems. In particularly severe cases, such infections can even be fatal.
A doctor will typically only order a wound culture when there is evidence that a patient's wound may be infected. Such evidence typically includes abnormal wound color, fluid emissions from the wound, or in advanced cases, general sickness accompanied by wound abnormality. In some cases, a health professional may begin treatment before the results of the wound culture actually return. This is common when a doctor strongly suspects a specific kind of infection and wants to begin treating it as soon as possible. A wound culture may also be ordered after treatment to verify the effectiveness of the treatment.