Properties

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment & Prevention

Gram negative cocci.

Seen in pairs (diplococci)

Contain endotoxin in outer membrane.

Growth is inhibited by toxic trace metals & fatty acids.

Oxidase-positive.

Transmission:

- cause disease only in humans.

- transmitted sexually.

- newborns infected during birth.

- usually symptomatic in men but often asymptomatic in women.

Does not possess a polysaccharide capsule.

Pili is an important virulence factors because they mediate attachment to mucosal cell surfaces & are antiphagocytic.

Two other virulence factors:

- endotoxin

- IgA

Infect primarily mucosal surface.

Immunity does not develop after infection; multiple reinfections may occur.

Diseases:

- localized infections in genital tract.

- disseminated infections with seeding of various organs.

Gonorrhea in men:

- acute urethritis

- dysuria

- purulent discharge.

Gonorrhea in women:

- infection localized in endocervical canal.

- purulent vaginal discharge.

- intermenstrual bleeding.

- acute salpingitis – sterility & scarring.

- spread further to cause acute pelvic inflammatory disease.

- infection around liver: Fitz-Hugh-Curtis syndrome.

- vulvovaginitis in prepubertal girls.

Both sex:

- throat: pharyngitis

- disseminated infection with fever, joint pain/infection & small pustular skin lesions.

Gonococcal conjunctivitis:

- ophthalmia neonatorum in newborn infants.

- acquired from mother during passage through birth canal.

May coexist with other sexually transmitted infections, e.g. syphilis.

Gram-negative diplococci within PMNs in a sample of urethral discharge.

Culture:

- on Thayer-Martin medium.

- oxidase-positive colony composed of gram-negative diplococci.

ELISA detects gonococcal antigens.

DNA probe assay detects gonoccal ribosomal genes.

Serologic tests are not useful for diagnosis.

Ceftriaxone & ciprofloxacin are used.

Tetracycline recommended for mixed infections with C.trachomatis.

Prevention:

- use of condoms

- prompt treatment of symptomatic patients & their contacts.

- gonococcal conjunctivitis in newborns prevented by use of erythromycin ointment or silver nitrate droplets.

No vaccine.