virulence factors

virulence factors

1. enzymes

   • enhance virulence by breaking downlaltering host cells to allow virus to get access to nutrients
   • protects virus by interfering with host defenses
     • coagulase
       • promotes fibrin to be deposited on S. aureus to avoid detection

2. exotoxins

   • proteins released from pathogen
   • cytotoxins
     • causes cytoplasm to lyse
     • small, soluble, extracellular
     • hemolysin
       • lyse RBC
   • AB toxins
     • bind to host cell receptor (B) and transfers a damaging agent (A) across cell mem. = prevents proteins from being made
     • Diphtheria toxin
       • catalyzes ADP-riboylation of EF-2
       • prevents transfer of amino acids to making peptide chain in ribosome
     • botulinum toxin
       • blocks the release of acetylcholine to muscle
         • muscle can't contract
           • permanent relaxed state
       • paralysis
       • death by asphyxiatoin
   • superantigen toxin
     • immune boosting inflammation
     • fever, vomiting, mucus made, systematic shock
   • enterotoxins
     • affects small intestine causing vomiting and diarrhea

3. endotoxins

   • less toxic than exotoxins
   • bound and release in toxic amounts only when cells lyse