In-Depth Notes on Neisseria gonorrhoeae and Gonorrhea

Overview of Neisseria

  • Neisseria: 12 species with 2 main pathogens.
    • Neisseria gonorrhoeae: Causes gonorrhea.
    • Neisseria meningitidis: Known for meningitis.

Virulence Factors of Neisseria

  • Key virulence factors include:
    • Fimbria: Helps in adherence to host cells.
    • Capsules: Protects bacteria from phagocytosis.
    • Lipooligosaccharide: A component that aids in virulence (combination of Lipid A and sugar).
  • Loss of any of these factors results in a non-infectious state.

Neisseria gonorrhoeae

  • Gonorrhea: Commonly known as "the clap" or "the drip".
    • One of the oldest known diseases, described in 150 AD by Galen.
    • Second most reported infectious disease in the U.S. after chlamydia.
    • An estimated 62 million cases occur worldwide annually.

Symptoms of Gonorrhea

  • In Males:

    • Painful urination, purulent discharge from the urethra.
    • 80% present symptoms within a week of exposure.
    • Can lead to scarring or blockage, resulting in potential sterility if testes or vas deferens are affected.

  • In Females:

    • Primarily infects cervical cells, leading to possible unnoticed infections.
    • Symptoms may include mild urethritis or increased vaginal discharge.
    • Untreated infections can cause Pelvic Inflammatory Disease (PID) leading to abdominal pain and fever.
    • May ultimately result in permanent sterility or ectopic pregnancies.

Complications of Gonorrhea

  • Untreated gonorrhea can disseminate (0.5%-3% of cases).
  • Complications may involve:
    • Ophthalmia neonatorum in newborns from infected mothers, preventing blindness with proactive treatments.
    • Possible severe complications include:
    • Blindness
    • Corneal scarring
    • Inflammation of the iris
    • Corneal perforation
    • Pneumonia

Diagnosis of Gonorrhea

  • In Males:

    • Gram stain of urethra pus revealing white blood cells with intracellular gram negative diplococci.

  • In Females:

    • Culture is required due to presence of other gram negative diplococci in normal flora.
    • Utilization of chocolate base media with antibiotics (Thayer-Martin medium, New York City medium).
    • N. gonorrhoeae is sensitive to cold; therefore, specimen transport must be timely or under specific atmospheric conditions.
    • Alternatives include ELISA, DNA, RNA probes, or monoclonal antibody tests for faster diagnosis.

Treatment of Gonorrhea

  • Historically treated with penicillin; however, it is no longer effective.
  • Current drug of choice (DOC): Ceftriaxone (single intramuscular dose) plus oral Azithromycin.
  • Partner testing and treatment is essential, regardless of symptoms.

Historical Treatment of Gonorrhea

  • Silver nitrate was commonly used until the late 19th century.
  • Replaced by Protargol (colloidal silver) and transitioned to antibiotics in the 1940s.