Throat Swab for Culture and Sensitivity

Function

A Throat Swab Culture is used to detect the presence of harmful bacteria in the posterior pharynx and tonsillar area. While the throat is naturally colonized by many 'good' bacteria (normal flora), certain pathogens can cause significant infection and systemic complications if left untreated. The test involves streaking the swab across a growth medium to see if specific colonies develop.

Why it is Ordered

This test is most frequently ordered to distinguish between a viral sore throat and a bacterial infection, specifically 'Strep Throat.' Clinical symptoms often overlap, making the culture the gold standard for diagnosis. Indications include:

• Severe sore throat with difficulty swallowing.
• Swollen, red tonsils with white patches or pus (exudate).
• Tiny red spots on the roof of the mouth (petechiae).
• Swollen lymph nodes in the neck.
• Absence of a cough (which usually points toward a viral cause).

Associated Conditions

The primary target of this culture is Streptococcus pyogenes, also known as Group A Beta-Hemolytic Streptococcus. If left untreated, Strep A can lead to serious complications such as:

• Rheumatic Fever: A disease that can affect the heart, joints, brain, and skin.
• Post-Streptococcal Glomerulonephritis: An inflammatory kidney disease.
• Peritonsillar Abscess: A collection of pus behind the tonsils.

Other bacteria like Neisseria gonorrhoeae or Corynebacterium diphtheriae may be sought in specific clinical contexts, though they usually require specialized media.