Virulence factors and resistances

• Enzymes
  • Catalase: protection against ROS
  • Coagulase: protection against phagocytosis
  • Hyaluronidase
  • Lipase
  • Penicillinase: a β-lactamase
• Toxins
  • Superantigens
    • Toxic shock syndrome toxin-1 (TSST-1)
    • Enterotoxin B (heat stable)
      • Can cause Food poisoning
  • Exfoliative toxin
  • Leukocidin: creates pores in the membranes of infected cells → necrotic skin and mucosal lesions
• Proteins
  • Protein A (binds to the Fc region of IgG), prevents opsonization and phagocytosis
  • Modified penicillin-binding protein (PBP) in MRSA
• Capsular polysaccharides
  • Promote colonization and persistence in host tissues