What is the most commonly used nonselective medium for isolation of Neisseria gonorrhoeae?

What is the most commonly used nonselective medium for isolation of Neisseria gonorrhoeae?

• A. Chocolate agar
• B. Cefsulodin-irgasan-novobiocin agar
• C. Martin-Lewis agar
• D. Modified Thayer-Martin agar

Answer: (A)

Neisseria gonorrhoeae is a fastidious organism that grows best on enriched media. Chocolate agar provides abundant nutrients and growth factors released from lysed red blood cells, without any antibiotics. This nonselective environment supports gonococcal growth alongside other flora, making chocolate agar the most common choice when you want to isolate the organism without selective inhibition. The other media listed include antibiotics or inhibitory components to suppress competing organisms, so they’re not nonselective and are used in different isolation scenarios.

Neisseria gonorrhoeae is a fastidious organism that grows best on enriched media. Chocolate agar provides abundant nutrients and growth factors released from lysed red blood cells, without any antibiotics. This nonselective environment supports gonococcal growth alongside other flora, making chocolate agar the most common choice when you want to isolate the organism without selective inhibition. The other media listed include antibiotics or inhibitory components to suppress competing organisms, so they’re not nonselective and are used in different isolation scenarios.