On Gram stain, a morphology that resembles 'seagull wings' is most characteristic of which organism?

• A. Campylobacter jejuni
• B. Neisseria gonorrhoeae
• C. Plesiomonas shigelloides
• D. Yersinia pseudotuberculosis

Answer: (A)

The seagull-wing appearance on Gram stain is classic for curved, motile Campylobacter species, especially Campylobacter jejuni. These bacteria are Gram-negative rods that bend into a distinct curved or S-shaped form, so when seen in smears they resemble two wings of a seagull. This morphology sets them apart from the other organisms listed: Neisseria gonorrhoeae appears as Gram-negative diplococci; Yersinia pseudotuberculosis is a small coccobacillus; and Plesiomonas shigelloides is a curved Gram-negative rod but does not typically show the characteristic seagull-wing shape. Campylobacter jejuni is also notable for being microaerophilic and often associated with gastroenteritis after poultry exposure.