Microbiological testing of the pharyngeal swab includes culture for the most common causes of microbial pharyngitis.
Throat
The most common cause of bacterial pharyngitis is group A Streptococcus (Lancefield), Streptococcus pyogenes. Healthy carriers of group A Streptococcus are usually children at a rate of up to 20%, while carrier rates are much lower in adults. In these individuals (carriers), isolating group A Streptococcus does not necessarily imply infection.
The extrapharyngeal manifestations of group A Streptococcus infection can be divided into those associated with the acute illness and post-streptococcal sequelae, such as acute rheumatic fever and glomerulonephritis, which occur 2-3 weeks after the pharyngeal infection. In the acute infection, bacteremia and streptococcal toxic shock may occur. Post-streptococcal sequelae appear to be restricted to specific microbe serotypes.
Group C Streptococcus (Lancefield) has also been reported as a cause of pharyngitis. The majority of these species, however, rarely cause disease in humans. This group includes the species and subspecies Streptococcus equi zooepidemicus, Streptococcus equi equi, and Streptococcus dysgalactiae dysgalactiae. The β-hemolytic group C Streptococcus, such as Streptococcus dysgalactiae equisimilis and the Streptococcus anginosus group (formerly the S. milleri group), which includes Streptococcus constellatus pharyngis and Streptococcus anginosus, are very rarely involved in bacterial pharyngitis.
Group G Streptococcus, known to cause pharyngitis, is subdivided into Streptococcus dysgalactiae equisimilis and Streptococcus anginosus.
Important Note
Laboratory test results are the most critical parameter for diagnosing and monitoring all pathological conditions. Between 70 to 80% of diagnostic decisions are based on laboratory tests. Correctly interpreting laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be analyzed based on each case and family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
