MicrobeLibrary - Gram Stain of Urethral Discharge with Intracellular Neisseria gonorrhoeae

The direct Gram stain of a urethral discharge from males with urethritis is a rapid and sensitive screening test for Neisseria gonorrhoeae infection. This image shows gram-negative diplococci within polymorphonuclear leukocytes. Cocci are 0.6 to 1.0 mm in diameter and can occur singly, but are more often found in pairs with adjacent sides flattened (diplococci). Bacterial culture and carbohydrate fermentation studies provide definitive identification of the organism. N. gonorrhoeae is the etiological agent of the sexually transmitted disease gonorrhea. Infections caused by this organism are localized to the mucosal surfaces in the area of initial exposure to the organism (e.g., cervix, conjunctiva, pharyngeal surface, anorectal area, or urethra of males). The organism may also be spread from infected mother to newborn during birth.

This image is of a Gram stain of urethral discharge from a symptomatic male with urethritis. A urethral discharge was collected by inserting a flexible swab 2 to 4 cm into the urethra and rotating for 2 seconds. Then the specimen collected was rolled directly onto the surface of a clean, dry glass slide, heat fixed, stained using Gram stain technique, and examined under an oil immersion objective. After examination, stained slides should be discarded in an appropriate container.

1. Forbes, B. A., D. F. Sahm, and A. S. Weissfeld. 2002. Bailey & Scott´s diagnostic microbiology, p. 502–509. Mosby, St. Louis, MO

2. Whiley, D. M., J. W. Tapsall, and T. P. Sloots. 2006. Nucleic acid amplification testing for Neisseria gonorrhoeae: an ongoing challenge. J. Mol. Diagn. 8:3–15.