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A throat culture is a
test to find germs (such as bacteria or a fungus) that can cause an infection. A sample of cells from the back of your throat is added to a substance that promotes the growth of germs. If no germs grow, the culture is negative. If germs that can cause infection grow, the culture
is positive. The type of germ may be identified using a microscope or chemical tests. Sometimes other tests are done to find the right medicine for treating the infection. This is called sensitivity testing.
Examples of infections that may be found during a
throat culture include:
If bacteria grows in the culture, other tests may be
done to check which antibiotic will treat the infection best. This is called
Most sore throats are caused by an infection with a virus, such as a cold or flu. Throat cultures are not done for viral infections because it is very hard to grow viruses and it is expensive.
A throat culture may be done
You do not need to do anything before
you have this test. Tell your doctor if you have recently taken
You will be asked to tilt your head
back and open your mouth as wide as possible. Your doctor will
press your tongue down with a flat stick (tongue depressor) and then examine
your mouth and throat. A clean swab will be rubbed over the back of your
throat, around your tonsils, and over any red areas or sores to collect a
The sample may also be collected using a throat washout.
For this test, you will gargle a small amount of salt water and then spit the
fluid into a clean cup. This method gives a larger sample than a throat swab
and may make the culture more reliable.
If your child needs a
throat culture, you may hold your child on your lap while the sample is taken. This can prevent your
child from moving around too much.
You may feel like gagging when the swab
touches the back of your throat. If your throat is sore, the swabbing may be
Generally there is no chance of problems with
collecting a sample for a throat culture. Your doctor can talk to
you about any specific risks of the test.
A throat culture is a test to find a
fungal infection in the throat. Throat culture test
results for bacterial infections are ready in 1 to 2 days, depending on which
bacteria are being tested for. Test results for a fungus may take about 7
Rapid strep test results are ready in 10 to 15 minutes. This
test is only for bacterial infections caused by strep bacteria.
No strep bacteria are detected. A throat culture may be
Strep bacteria are detected. This means you have
strep throat. Antibiotics can be started
No infection (bacteria or fungi) grows in
A negative throat culture may mean that the
cause of your infection is a
virus, rather than bacteria or fungus.
Some viruses that cause throat infections include:
Bacteria grows in the culture. Some
bacterial throat infections include:
Fungus grows in the culture. The most
common fungal throat infection is
thrush, caused by the fungus Candida albicans.
Reasons you may not be able to
have the test or why the results may not be helpful include:
Other Works Consulted
American Academy of Pediatrics (2015). Group A streptococcal infections. In LK Pickering et al., eds., Red Book: 2015 Report of the Committee on Infectious Diseases, 28th ed., pp. 616–628. Elk Grove Village, IL: American Academy of Pediatrics.
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
ByHealthwise StaffPrimary Medical ReviewerE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineSpecialist Medical ReviewerMartin J. Gabica, MD - Family Medicine
Current as ofMarch 23, 2016
Current as of:
March 23, 2016
E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Martin J. Gabica, MD - Family Medicine
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