Neisseria spp: Overview


Neisseria spp.

  • Includes:
    • Neisseria gonorrhoeae
    • Neisseria meningitidis
  • Gram-negative diplococci
    • Contain lipooligosaccharides (LOS) with strong endotoxin activity
  • Facultatively intracellular
    • Often visualized within epithelial cells
  • Grows on Thayer-Martin agar
    • Selective chocolate (heated-blood) agar-based medium containing the antibiotics vancomycin, colistin, nystatin and trimethoprim
    • Prevents growth of microbes other than Neisseria
  • Produce IgA protease
    • Cleave IgA at hinge region, impairing its function at mucosal surfaces
    • Improves mucosal adherence
  • Increased risk with terminal complement deficiency (C5-C9)
    • Inability to generate membrane attack complex (MAC) leads to poor clearance of bacteria
  • Pili
    • Hair-like proteins that facilitates attachment to mucosal surfaces
      • Nasopharynx for N. meningitidis, vaginal/urethral for gonorrhoea
    • No vaccine due to antigenic variation of pilus proteins 
  • Disseminated infections present with petechial skin rash
    • Due to small-vessel vasculitis