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Throat swab culture

A throat swab culture is a laboratory test that is done to identify germs that may cause infection in the throat. It is most often used to diagnose strep throat.

How the Test is Performed

You will be asked to tilt your head back and open your mouth wide. Your health care provider will rub a sterile cotton swab along the back of your throat near your tonsils. You will need to resist gagging and closing your mouth while the swab touches this area.

Your provider may need to scrape the back of your throat with the swab several times. This helps improve the chances of detecting bacteria.

How to Prepare for the Test

DO NOT use antiseptic mouthwash before this test.

How the Test will Feel

Your throat may be sore when this test is done. You may feel like gagging when the back of your throat is touched with the swab, but the test only lasts a few seconds.

Why the Test is Performed

This test is done when a throat infection is suspected, particularly strep throat. A throat culture can also help your provider determine which antibiotic will work best for you.

Normal Results

A normal or negative result means no bacteria or other germs that may cause a sore throat were found.

What Abnormal Results Mean

An abnormal or positive result means bacteria or other germs that can cause a sore throat were seen on the throat swab.

Risks

This test is safe and easy to tolerate. In very few people, the sensation of gagging may lead to an urge to vomit or cough.

Alternative Names

Throat culture and sensitivity; Culture - throat

References

Bryant AE, Stevens DL. Streptococcus pyogenes. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 197.

Nussenbaum B, Bradford CR. Pharyngitis in adults. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 9.

Stevens DL, Bryant AE, Hagman MM. Nonpneumococcal streptococcal infections and rheumatic fever. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 274.

Tanz RR. Acute pharyngitis. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 409.

Review Date 1/23/2020

Updated by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.