Snapshot A 19-year-old male college student presents to the clinic complaining of a burning sensation with urination as well as purulent urethral discharge. He admits to rarely using condoms during sexual intercourse, and does not recall the last time he was tested for sexually-transmitted infections. Urinalysis is positive for leukocyte esterase and a Gram stain shows intracellular diplococci within polymorphonuclear neutrophils. Introduction Classification Neisseria Gram-negative diplococci often intracellular within neutrophils Epidemiology incidence the second most common bacterial sexually-transmitted infection (after Chlamydia) location genital tract risk factors unprotected sexual intercourse Pathogenesis mechanism molecular biology pili facilitate attachment to mucosal surfaces antigenic variation IgA protease allows invasion of mucosal surfaces contains lipooligosaccharides (LOS) with strong endotoxin activity invasion of mucosal surfaces results in inflammation transmission sexual perinatal Associated conditions septic arthritis neonatal conjunctivitis (2-5 days after birth) prophylaxis with erythromycin eye drops pelvic inflammatory disease (PID) Fitz-Hugh-Curtis syndrome Presentation Symptoms dysuria purulent discharge fever prostatitis (men) endocervicitis (women) urethritis Studies Labs Cervical and urethral culture Thayer-Martin agar selects for growth of Neisseria contains vancomycin, trimethoprim, colistin, and nystatin to inhibit growth of Gram-positive organisms, Gram-negative organisms except for Neisseria, and fungi Nucleic acid amplification testing (NAAT) Histology Gram stain of a cervical swab Gram-negative kidney-shaped diplococci Differential Chlamydia distinguishing factor visualization of intracytoplasmic inclusions (reticulate bodies) on histology Urinary tract infection distinguishing factor lack of growth on Thayer-Martin agar Genital herpes simplex distinguishing factor painful vesicles and ulcers Treatment Medical IM ceftriaxone add azithromycin or doxycycline for possible concomitant chlamydial infection Complications Pelvic inflammatory disease (PID) may include salpingitis, endometritis, hydrosalpinx, tubo-ovarian abscess risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and adhesions Fitz-Hugh-Curtis Syndrome perihepatitis infection and inflammation of liver capsule adhesions of peritoneum to liver Comparison with N. meningitidis Comparison with N. meningitidis Characteristics N. gonorrhoeae N. meningitidis Appearance Kidney-bean shaped diplococci Kidney-bean shaped diplococci Oxidase test Positive Polysaccharide capsule No Yes Fermentation Glucose ("Gonococci") Maltose and Glucose ("MeninGococci") Transmission Sex Respiratory Vaccine No (due to rapid antigenic variation) Yes β-lactamase production Common Rare IgA protease production Yes Yes