"The family Neisseriaceae comprises the genera Neisseria, Moraxella, Kingella, and Acinetobacter. The only significant human pathogens are N gonorrhoeae, the agent of gonorrhea, and N. meningitidis, an agent of acute bacterial meningitidis. N gonorrhoeae infections have a high prevalence and low mortality, whereas N meningitidis infections have a low prevalence and high mortality. Moraxella is an oxidase-positive bacterium, sometimes mistaken for Neisseria, that may be isolated from eye infections and respiratory tract infections. Moraxella catarrhalis causes lower respiratory infection in adults with chronic lung disease and is a common cause of otitis media, sinusitis, and conjunctivitis in children. Kingella and Eikenella species are short bacilli or coccoid bacteria that act as opportunistic pathogens. They are sometimes secondary invaders of damaged tissues."

http://gsbs.utmb.edu/microbook/ch014.htm

Neisseria gonorrhoeae is a fastidious organism requiring growth factors which are present in hemolyzed blood cells. Thayer-Martin chocolate agar plates have VCN antibiotics which prevent growth of most organisms while supporting N gonorrhoeae growth. The gram stain is considered by many as the single most important characteristic of clinical bacteria. However the gram stain itself is not used for the identification of organisms. One rare exception would of course be a gram stain of urethral discharge which contains gram negative cocci in pairs inside neutrophils. GNID, gram-negative intracellular diplococci. are widely regarded as pathonomonic for Neisseria gonorrhoeae infection. On gram-stain they are among the smallest of bacteria. As a result, it takes a little practice to be able to quickly recognize their distinctive diplococcoid shape. You may have heard the term, "kidney bean shaped." But they are so small that you have to have an imagination to see that. When seen in the pus of a urethral smear their presence is usually so obvious as to be unmistakable. There will almost always be wall to wall neutrophils which microbiologists have a habit of calling PMN's or polymorphonuclear leukocytes since they are gram stained and not stained with a Wright's stain.. And the tiny diplococci must be seen within the boundaries of some of the PMN's to qualify as GNID.

In Japan infection with this organism is so uncommon that it is classified as "rare."

"The only distinguishing structural feature between N meningitidis and N gonorrhoeae is the presence of a polysaccharide capsule in the former. The capsule is antiphagocytic and is an important virulence factor."

http://gsbs.utmb.edu/microbook/ch014.htm

Here is a GNID image from "Doc" Kaiser's collection. http://www.cat.cc.md.us/~gkaiser/labmanua/lab16/gc.html

Urethral Smear GNID, Loyola University website:
http://www.meddean.luc.edu/lumen/DeptWebs/microbio/med/gram/slides/slide1.htm

SEM x27,200 electron micrograph courtesy of Dennis Kunkel. Click thumbnail to go to the EM website.

Also the image gallery at ASM:

http://gsbs.utmb.edu/microbook/ch014.htm