Burn INfections

Question 1

Pseudomonas aeruginosa

Answer 1

Burn Infections
• G(-) ROD
• *ubiquitous
• soil, water, plants
• occasional normal microbiota skin, intest. (primarily hospitalized, immunocompromised)
• opportunist- wide range localized and systemic infect.
• *healthcare associated infections (HAIs)
• encapsulated
• motile, flagella
• *Obligate aerobe
• *oxidase +
• nonfermenter
• wide temp. range, 4-42°C
• salt-tolerant
• growth in distilled H20
─ simple C and N requirements
DISEASE
- **Ecthyma Gangrenosum (after burns)
LAB
• variety media: Blood, MacConkey
─ mucoid colonies
─ +/- odor of grapes 
─ +/- color: some strains produce pigments
1) *pyocyanin (blue)
   • stimulates IL-8 release → *PMN attractant (helps build biofilms?)
2) *pyoverdin (green
VIRULENCE
─ *alginate capsule (mucoid polysaccharide)
• *spreading factors:
   ─ *collagenase [Ecthyma Gangrenosum]
   ─ *elastase [Ecthyma Gangrenosum]
─ exotoxin A 
─ *biofilm formation
   a) *ALGINATE = major component
─ *intrinsic and acquired antibiotic resistance

Question 2

Ecthyma Gangrenosum

Answer 2

Burn Infections
• The rash that follows *septic infect.
• maculopapular lesions that become hemorrhagic, bullous, and eventually ulcerative w/ a *central necrotic black eschar
• Single