The organism whose isolation can be hindered by fatty acids present in clinical specimens is which?

• A. Neisseria gonorrhoeae
• B. Vibrio cholerae
• C. Aeromonas
• D. Rahnella

Answer: (A)

Fatty acids in clinical specimens can block the growth of certain bacteria, and Neisseria gonorrhoeae is particularly sensitive to these inhibitors. Because gonococcus is fastidious and relies on enriched, selective conditions to grow, the presence of fatty acids can prevent its isolation on routine media, leading to false negatives. To overcome this, labs use specialized media and processing that reduce inhibitors and suppress competing flora, such as selective media designed for Neisseria gonorrhoeae, which improves recovery from specimens. The other organisms listed are less affected by fatty acids in the same way and are not routinely hindered during isolation from clinical samples, so they are not the best match for this scenario.