Which statement accurately describes Neisseria gonorrhoeae?

• A. It is a Gram-positive diplococcus.
• B. It is a Gram-negative diplococcus that grows on Thayer-Martin medium and causes purulent urethral discharge.
• C. It does not cause urethral discharge.
• D. It is a Gram-negative diplococcus that grows on standard blood agar.

Answer: (B)

Neisseria gonorrhoeae is a Gram-negative diplococcus that is fastidious and causes urethral infection with purulent discharge. It grows best on selective, enriched media like Thayer-Martin, which contains antibiotics to suppress competing bacteria and fungi, allowing this organism to flourish in a CO2-rich environment. It does not grow well on standard blood agar because it relies on enriched, selective conditions to isolate it from normal flora.

So the statement describing a Gram-negative diplococcus that grows on Thayer-Martin medium and causes purulent urethral discharge correctly captures its identification, while the other statements are inaccurate because the organism is not Gram-positive, it does cause urethral discharge, and it does not grow on standard blood agar.