Neisseria gonorrhoeae

Overview
Neisseria gonorrhoeae (also known as Gonococci) is a species of Gram-negative bacteria responsible for the sexually transmitted disease gonorrhoea. Neisseria are highly fastidious cocci, requiring nutrient supplementation to survive. Thus, they grow on Chocolate agar (heated blood agar) with carbon dioxide. These cocci are facultatively intracellular and typically appear in pairs (diplococci).

Gonorrhoea symptoms include a purulent (or pus-like) discharge from the genitals which may be foul smelling, a burning sensation during urination and conjunctivitis commonly in neonates; that's why silver nitrate is used as a preventive measure. It also occurs occasionally in adults. Neisseria is usually isolated on a Thayer-Martin agar &mdash; an agar plate with 3 different antibiotics and nutrients which not only facilitate the growth of Neisseria species, but inhibit the growth of Gram-positive organisms and most bacilli and fungi. Further testing to differentiate the species includes testing for oxidase (all Neisseria show a positive reaction) and the carbohydrates maltose, sucrose, and glucose test in which N. gonorrhoeae will only oxidize (that is, utilize) the glucose.

If N. gonorrhoeae is resistant to the penicillin family of antibiotics, then ceftriaxone (a third-generation cephalosporin) is often used.

Patients should also be tested for Chlamydia infections, since co-infection is frequent.