A throat culture is a technique for identifying disease bacteria in material taken from the throat. Most throat cultures are done to rule out infections caused by beta-hemolytic streptococci, which cause strep throat. Hemolytic means that these streptococci destroy red blood cells. These organisms are Group A streptococci, specifically Streptococcus pyogenes. Since most sore throats are caused by viral infections rather than by S. pyogenes, a correct diagnosis is important to prevent unnecessary use of antibiotics and to begin treatment of strep infections as soon as possible. Group A streptococcal infections are potentially life-threatening, often involving other parts of the body in addition to the throat. Besides causing sore throat (pharyngitis), streptococci can also cause scarlet fever, rheumatic fever, kidney disease, or abscesses around the tonsils.

Throat cultures can also be used to identify other disease organisms that are present in the patient's throat; and to...