Neisseria gonorrhoeae (Gram Negative Bacteria)

Neisseria are fastidious Gram-negative cocci that require nutrient supplementation to grow in laboratory cultures. Specifically, they grow on chocolate agar with carbon dioxide. These cocci are facultatively intracellular and typically appear in pairs (diplococci), in the shape of coffee beans. Of the eleven species of Neisseria that colonize humans, only two are pathogens. N. gonorrhoeae is the causative agent of gonorrhoea and is transmitted via sexual contact.[2]

Neisseria is usually isolated on Thayer-Martin agar—an agar plate containing antibiotics (Vancomycin, Colistin, Nystatin, and SXT) and nutrients that facilitate the growth of Neisseria species while inhibiting the growth of contaminating bacteria and fungi. Further testing to differentiate the species includes testing for oxidase (all clinically relevant 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.

N. gonorrhoeae are motile (twitching motility) and possess type IV pili to adhere to surfaces. The type IV pili operate mechanistically similar to a grappling hook. Pili extend and attach to a substrate which signals the pilus to retract, dragging the cell forward. N. gonorrhoeae are able to pull 100,000 times their own weight and it has been claimed that the pili used to do so are the strongest biological motor known to date, exerting one nanonewton.[3]

"N. gonorrhoeae" is naturally competent for DNS transformation as well as being capable of conjugation. Both of these concepts allow for the DNA of N. gonorrhoeae the ability to undergo conformational changes. Especially dangerous to the health industry is the ability to conjugate since this can lead to antibiotic resistance.
[edit] Disease
Main article: Gonorrhoea

Symptoms of infection with N. gonorrhoeae differ depending on the site of infection. Note also that 10% of infected males and 50% of infected females are asymptomatic.

Infection of the genitals can result in a purulent (or pus-like) discharge from the genitals which may be foul smelling. Symptoms may include inflammation, redness, swelling, dysuria and a burning sensation during urination.

N. gonorrhoeae can also cause conjunctivitis, pharyngitis, proctitis or urethritis, prostatitis and orchitis.

Conjunctivitis is common in neonates (newborns), and silver nitrate or antibiotics are often applied to their eyes as a preventive measure against gonorrhoea. Neonatal gonorrheal conjunctivitis is contracted when the infant is exposed to N. gonorrhoeae in the birth canal and can lead to corneal scarring or perforation, resulting in blindness in the neonate.

Disseminated N. gonorrhoeae infections can occur, resulting in endocarditis, meningitis or gonococcal dermatitis-arthritis syndrome. Dermatitis-arthritis syndrome presents with arthralgia, tenosynovitis and painless non-pruritic (non-itchy) dermatitis.

Infection of the genitals in females with N. gonorrhoeae can result in pelvic inflammatory disease if left untreated, which can result in infertility. Pelvic inflammatory disease results if N. gonorrhoeae travels into the pelvic peritoneum (via the cervix, endometrium and fallopian tubes). Infertility is caused by inflammation and scarring of the fallopian tube. Infertility is a risk to 10 to 20% of the females infected with "N. gonorrhoeae".
[edit] Treatment and Prevention

If N. gonorrhoeae is resistant to the penicillin family of antibiotics, then ceftriaxone (a third-generation cephalosporin) is often used. Sexual partners should also be notified and treated.

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

Transmission can be reduced by the usage of condoms during intercourse, oral and anal sex, and by limiting sexual partners.