1/26/2016 Streptococcal Skin Infections ·Erysipelas -5.pyogenes infects the dermal layer of the skin Starts as a rash:Causes local tissue destruction and sepsis Appears first on the face and is often preceded by Strepfococcal soar Throat Still sensitive to antibiotics Streptococcal Skin Infections Infections by Pseudomonads Necrotizing fasciitis -15,000 cases in the US each year with mortality rates Pseudomonas aeruginosa of40% -Gram-negative,aerobic rod:soil and water: -"Flesh-eating"disease grows on unusual organic matter uyo oribute -Pyocyanin produces a blue-green pus igen causing the -Associated with streptococcal toxic shock syndrome: -Pseudomonas dermatitis similar to staphylococcal TSS:higher mortality rate Self-limiting rash acquired in swimming pools Otitis externa "Swimmer's ear Resistant to many antibiotics1/26/2016 8 M protein on fibrils Streptococcal Skin Infections • Erysipelas – S. pyogenes infects the dermal layer of the skin • St t h C l l ti d t ti d Starts as a rash; Causes local tissue destruction and sepsis • Appears first on the face and is often preceded by streptococcal soar throat • Still sensitive to antibiotics Streptococcal Skin Infections • Necrotizing fasciitis – 15,000 cases in the US each year with mortality rates of 40% – "Flesh-eating disease " disease – Extotoxin A produced by S. pyogenes acts as a superantigen causing the immune system to contribute to the damage – Associated with streptococcal toxic shock syndrome; similar to staphylococcal TSS; higher mortality rate Infections by Pseudomonads • Pseudomonas aeruginosa – Gram-negative, aerobic rod; soil and water; g g rows on unusual organic matter – Pyocyanin produces a blue-green pus – Produces exo- and endotoxins; grows in biofilms; health-care associated infections – Pseudomonas dermatitis • Self-limiting rash acquired in swimming pools – Otiti t Otitis externa • "Swimmer's ear" – Opportunistic in burn patients and cystic fibrosis patients (biofilm) – Resistant to many antibiotics