Throat Culture

A throat culture is a laboratory diagnostic test to find a bacterial or fungal infection in the throat. Sampling is performed by throat swab, and the sample is put in a special cup (culture) that allows infections to grow. If an infection grows, the culture is positive. The type of infection is found using a microscope, chemical tests, or both. If no infection grows, the culture is negative.

Examples of infections that may be found during a throat culture include:

• Candida albicans

This fungus causes thrush, an infection of the mouth and tongue and sometimes of the throat. See a picture of thrush in the mouth.

• Group A streptococcus

This bacteria can cause strep throat, scarlet fever, and rheumatic fever. If strep throat is likely, a test called a rapid strep test (or quick strep) may be done before a throat culture. With a rapid strep test, results are ready in 10 minutes instead of 1 to 2 days with a throat culture. If the rapid strep test results are positive, antibiotics can be started immediately. A throat culture is more accurate than the rapid strep test. The rapid strep test can give false-negative results even when strep bacteria are present. When the results of a rapid strep test are negative, many health professionals recommend doing a throat culture to make sure that strep throat is not present.

• Neisseria meningitidis

This bacteria can cause meningitis. If bacteria grows in the culture, other tests may be done to check which antibiotic will treat the infection best. This is called susceptibility or sensitivity testing.