- amount of organism that if given to a patient could cause infection in 50% of the population.
damage tissues/cell membranes/connectivity to facilitate spread or modulate host cell function
- typically work on outside of host cells
- "invasins" or "exoenzymes"
- include many "-ase" enzymes
CC: Staphylococcus aureus or Streptococcus pyogenes (GAS)
Dx: Gram stains
-S. aureus if G+, cocci, clusters
-S. pyogenes if G+, cocci, chains
Treatment: topical antibiotics
CC: herpes simplex virus is most common
VF: viral, latency, spread
Dx: appearances and discharge type (clear = viral)
Treatment: aggressive corticosteroids and acyclovir or valacyclovir or Viroptic