Which statement about Neisseria gonorrhoeae is true?

Which statement about Neisseria gonorrhoeae is true?

• A. Adversely affected by fatty acids in clinical specimens
• B. Rapid growth on sheep blood agar
• C. Ferments glucose and maltose
• D. ONPG positive

Answer: (D)

This question tests how Neisseria gonorrhoeae is identified by its biochemical traits, especially enzyme activity and sugar use. The ONPG test measures beta-galactosidase activity by detecting cleavage of the substrate ONPG to a yellow compound. Neisseria gonorrhoeae typically shows a positive ONPG result, meaning it has beta-galactosidase activity detectable by this test. This helps distinguish it in the lab from other organisms with different enzyme profiles. In contrast, the other statements don’t fit the common identification pattern. Neisseria gonorrhoeae does not grow rapidly on routine sheep blood agar and instead requires enriched, selective media in a CO2-rich environment. It ferments glucose only, not maltose (so a pattern of glucose and maltose fermentation is incorrect). The notion about being adversely affected by fatty acids in clinical specimens is not a standard, reliable criterion used for identifying this organism, whereas ONPG positivity is a more specific, commonly tested trait.

This question tests how Neisseria gonorrhoeae is identified by its biochemical traits, especially enzyme activity and sugar use. The ONPG test measures beta-galactosidase activity by detecting cleavage of the substrate ONPG to a yellow compound. Neisseria gonorrhoeae typically shows a positive ONPG result, meaning it has beta-galactosidase activity detectable by this test. This helps distinguish it in the lab from other organisms with different enzyme profiles.

In contrast, the other statements don’t fit the common identification pattern. Neisseria gonorrhoeae does not grow rapidly on routine sheep blood agar and instead requires enriched, selective media in a CO2-rich environment. It ferments glucose only, not maltose (so a pattern of glucose and maltose fermentation is incorrect). The notion about being adversely affected by fatty acids in clinical specimens is not a standard, reliable criterion used for identifying this organism, whereas ONPG positivity is a more specific, commonly tested trait.