Throat Culture

Why am I having this test? A throat culture, also called a throat swab culture, is a medical test used to determine what type of bacteria is causing your sore throat. A throat culture is most often done to test for strep throat. This is a bacterial infection caused by the bacteria Streptococcus pyogenes. You may have this test if you have symptoms of strep throat. These include: • Throat pain. • Fever. • A red throat with yellow or white spots. • Neck swelling and tenderness. • Loss of appetite. • Trouble breathing or swallowing. • Rash. • Dehydration. The test can be done in your health care provider's office. Results are usually ready in 24–48 hours. A rapid strep test, another kind of strep test, gives results more quickly than a throat culture, but the results of a culture test are more accurate. Your health care provider may do this test to confirm the results of a rapid strep test. What is being tested? This test checks for the Streptococcus pyogenes bacteria in a fluid sample from your throat area. A throat culture can also identify the different strains of strep bacteria and other types of bacteria that can cause throat infections. What kind of sample is taken? This test requires a sample of fluid from the back of your throat and tonsils. Your health care provider may hold down your tongue with a tongue depressor and use a swab to collect the sample. In the lab, the culture sample is combined with a substance that encourages bacteria to grow. How do I prepare for this test? Do not use mouthwash that contains an antiseptic before having a throat culture. How are the results reported? Your test results will be reported as either positive or negative for a bacterial infection. A false-negative result can occur. A false negative is incorrect because the test is showing that a condition is not present when it is. This can happen if a poor sample was taken. What do the results mean? If the result of your throat culture is negative, it means that: • No bacteria grew from your culture sample. • It is likely that you do not have strep throat or another bacterial infection. • A virus may be causing your sore throat. Viral infections cannot be tested with a throat culture. If the result of your throat culture is positive, it means that: • Bacteria grew from your culture sample. • It is likely that you do have strep throat or another bacterial throat infection. • You may have to take antibiotic medicine. Talk with your health care provider about what your results mean. Questions to ask your health care provider Ask your health care provider, or the department that is doing the test: • When will my results be ready? • How will I get my results? • What are my treatment options? • What other tests do I need? • What are my next steps? Summary • A throat culture, also called a throat swab culture, is a medical test used to determine what type of bacteria is causing your sore throat. It is most often done to test for strep throat. • Your health care provider may do this test to confirm the results of a rapid strep test or if your rapid test result was negative. • This test requires a sample of fluid from the back of your throat and tonsils. In the lab, the culture sample is combined with a substance that encourages bacteria to grow. • The throat culture identifies the bacteria causing your sore throat. This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.