Medical Microbiology

StreptococcusandEnterococcus 239

StreptococcuspyogenesInfections

S. pyogenes (M protein, PSE, other pathogenicity factors)

Host organism

Anti-M antibody (+) Anti-M antibody (–)

Silent infection

Anti-PSE antibodies (–)

Local infection

Anti-PSE antibodies (–)

and high-risk MHC II

allotype

Invasion via skin or mucosa

a

impetigo,

erysipelas,

cellulitis,

lymphangitis,

sinusitis,

otitis media,

tonsillitis

or Generalized invasive infection

sepsis

septic shock

necrotizing fasciitis

scarlet fever

(tonsillitis)

Fig.4. 4 aPathogenesisandclinicalpictures

ofS.pyogenesinfections(simplifiedscheme).

bErysipelascausedbyS.pyogenes.

4

Kayser, Medical Microbiology © 2005 Thieme