Transmission electron micrograph (TEM) of negatively stained lysed Neisseria gonorrhoeae. Old culture showing diplococcal feature and flagella. Note pits or holes in the membrane. Neisseria are gram-negative and usually occur in pairs with flattened sides but may occur singly or in irregular groups. N. gonorrhoeae is the causative agent of gonorrhea, a specific, contagious, catarrhal inflammation of the genital mucous membrane of either sex. The disease may also affect other parts of the body such as the heart, conjunctiva, oral mucosa, rectum or joints. In the female, the parts involved may be the urethra, vulva, vulvovagnial glands, vagina, endocervix, Skene's glands, Bartholin's glands or fallopian tubes. In the male, a yellow mucopurulent discharge from the penis results from inflammation of the urethra, which may become deep-seatetd and affect the prostate. This causes slow, difficult and painful urination and sometimes painful induration of the penis. Magnification: 20,000x at 2 1/4 film size.