The flattened adjacent sides of the cellular appearance of which microorganism are said to resemble kidney beans?

• A. Aeromonas hydrophila
• B. Campylobacter jejuni
• C. Neisseria gonorrhoeae
• D. Pasteurella multocida

Answer: (C)

Recognizing the distinctive diplococcal morphology is what this item tests. Neisseria gonorrhoeae appears as Gram-negative diplococci that are often seen in pairs with flattened areas on the sides of the adjacent cocci, giving a kidney-bean shape. This paired, bean-like appearance is a classic clue in clinical specimens (such as urethral or cervicovaginal exudates) and helps distinguish gonococci from other Gram-negative bacteria.

Other organisms listed do not share this kidney-bean diplococcal form: Aeromonas hydrophila are rod-shaped, Campylobacter jejuni are curved rods, and Pasteurella multocida are small coccobacilli. The kidney-bean shape with flattened adjacent sides is characteristic of Neisseria gonorrhoeae.