Which swab is ideal for recovering Corynebacterium diphtheriae from the nasopharynx?

Corynebacterium diphtheriae, the causative agent of diphtheria, requires specific conditions for optimal recovery during diagnostic sampling. The flexible calcium alginate nasopharyngeal swab is ideal for this purpose because calcium alginate does not interfere with culture media, allowing for better growth of the bacteria. This type of swab is also designed to navigate the anatomical structures of the nasopharynx effectively, ensuring that samples are collected from the appropriate area where the bacteria reside.

Using a cotton swab, plastic swab, or wooden stick can introduce substances that may inhibit the growth of microorganisms or might not collect samples efficiently from the nasopharynx, leading to false-negative results. Calcium alginate swabs have a softer and more flexible tip, allowing for better contact with the mucosal surfaces and ensuring adequate cellular material is obtained for culture and testing.