Genus Neisseria

• What is the Gram stain result for the genus Neisseria?

  Gram -ve
• What enzyme test is positive for Neisseria?

  Oxidase +ve
• What is the shape of Neisseria bacteria?

  Diplococci
• On which type of agar does Neisseria grow?

  Chocolate agar
• What is VPN agar also known as?

  Thayer-Martin medium
• What is the consequence of a deficiency in late complements C5 & C9 for Neisseria?

  Increased infections/bacteremia
• What are the virulence factors of Neisseria?

  • Pili: antigenic variation, antiphagocytic, attachment
  • IgA1 Proteases: cleaves mucosal IgA for adherence
  • Lipooligosaccharide (LOS): endotoxin inducing TNF-alpha + IL-1
• What is the Gram stain result for Neisseria meningitidis?

  Gram -ve
• What is the oxidase test result for Neisseria meningitidis?

  Oxidase +ve
• What is the catalase test result for Neisseria meningitidis?

  Catalase +ve
• What is the shape of Neisseria meningitidis?

  Kidney-shaped diplococci
• What sugars can Neisseria meningitidis ferment?

  Maltose and Glucose
• What is the appearance of Neisseria meningitidis colonies?

  Small with compact center + translucent periphery
• What type of environment does Neisseria meningitidis require for growth?

  Aerobic with increased CO2 concentration
• What is the reservoir for Neisseria meningitidis?

  Human Nasopharynx
• How is Neisseria meningitidis transmitted?

  Respiratory droplets
• What are the virulence factors of Neisseria meningitidis?

  • Pili: attachment and antiphagocytic
  • IgA1 Protease: cleaves mucosal IgA
  • LOS: endotoxin inducing TNF-alpha + IL-1
  • Polysaccharide capsule: antiphagocytic + antigenic
• What are the clinical manifestations of Neisseria meningitidis infection?

  • Meningitis: headache, fever, stiff neck, altered mental status
  • Meningococcemia: high fever, organ failure, petechial rash
  • Waterhouse-Friderichsen Syndrome: DIC, adrenal hemorrhage
• What specimens are used for microbiological diagnosis of Neisseria meningitidis?

  • CSF
  • Blood
  • Nasopharyngeal secretions
• What is the CSF profile in Neisseria meningitidis infection?

  Leucocytosis with neutrophils, elevated protein, low sugar
• What are the steps for Gram staining in microbiological diagnosis?

  1. Prepare a smear
  2. Heat-fix the smear
  3. Apply crystal violet
  4. Add iodide
  5. Decolorize with alcohol or acetone
  6. Counterstain with safranin or carbol fuchsin
• What culture media are used for Neisseria meningitidis?

  • Chocolate Agar: for predominant samples
  • VPN Agar: for contaminated samples
• What molecular techniques are used for diagnosing Neisseria meningitidis?

  PCR and Latex Agglutination
• What is the treatment for Neisseria meningitidis infection?

  • IV High Dose Penicillin G
  • 3rd Gen Cephalosporins (e.g., Ceftriaxone)
  • Prophylaxis: Rifampin or Ciprofloxacin for close contacts
• What is the Gram stain result for Neisseria gonorrhoeae?

  Gram -ve
• What is the oxidase test result for Neisseria gonorrhoeae?

  Oxidase +ve
• Does Neisseria gonorrhoeae have a capsule?

  No capsule
• What sugar can Neisseria gonorrhoeae ferment?

  Glucose only
• What is the shape of Neisseria gonorrhoeae?

  Kidney-shaped diplococci
• Where does Neisseria gonorrhoeae reside in the human body?

  Genital tract
• How is Neisseria gonorrhoeae transmitted?

  Sexual contact and childbirth
• What are the virulence factors of Neisseria gonorrhoeae?

  • Pili: attachment and evasion of immune response
  • IgA1 Protease: cleaves mucosal IgA
  • LOS: endotoxin
  • Beta-lactamase: evades beta-lactam antibiotics
• What are the clinical manifestations of Neisseria gonorrhoeae infection?

  • Urethritis: dysuria, purulent discharge
  • Males: epididymitis, scrotal pain, prostatitis
  • Females: cervicitis, PID, septic arthritis, neonatal conjunctivitis
• What specimens are used for microbiological diagnosis of Neisseria gonorrhoeae?

  • Urine
  • Urethral and cervical exudates
  • Nasopharyngeal secretions
• What culture media are used for Neisseria gonorrhoeae?

  Chocolate Agar or VPN Agar
• What test is used to confirm Neisseria gonorrhoeae?

  Oxidase test
• What is the treatment for Neisseria gonorrhoeae infection?

  • 3rd Generation Cephalosporins (e.g., Ceftriaxone)
  • Doxycycline or Azithromycin for co-infection with Chlamydia