Skin and Wound Cultures
There is a very slight risk of spreading some infections if a biopsy is needed to collect the sample.
A skin or wound culture is a test to find and identify germs (such as bacteria, a fungus, or a virus) that may be growing on the skin or in a wound.
Some types of bacteria, fungi, and viruses grow quickly in culture, and some grow slowly. Test results may take from one day to several weeks, depending on the type of infection suspected.
Skin and wound cultures
No large numbers of harmful germs are found on the skin or in the wound. Normal culture results are negative.
Harmful germs are found on the skin or in the wound. Abnormal culture results are positive.
If test results are positive, sensitivity testing may be done help make decisions about treatment.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
- Taking or having recently taken antibiotics.
- Getting bacteria that is normally found on the skin in the tissue or wound sample.
What To Think About
- Types of bacteria that commonly cause infection in wounds are staph (Staphylococcus), strep (Streptococcus), and Clostridium perfringens, a bacterium found in soil and in stool (feces) that can cause gangrene. The most common type of fungus that causes infection in wounds is Candida albicans.
- Looking at fluid (such as pus) from a wound under a microscope can sometimes help identify the type of bacteria or fungi causing the infection before culture results are ready.
- A culture that does not grow any bacteria may not mean that you do not have an infection. Sometimes the amount of sample collected, the age of the wound (or skin problem), the type of culture done, and previous use of antibiotics can prevent the growth of bacteria in the culture.
- Testing for a virus may be done to detect and identify a viral infection in the body that is causing symptoms. To learn more, see the topic Viral Tests.
- Most types of fungi grow very slowly and may not show up in a culture for several weeks. Your doctor may recommend that you start treatment before your culture results come back if he or she thinks you could have a fungal infection.
- Sensitivity testing helps your doctor choose the best medicine to treat specific types of bacteria, viruses, or fungus.