2 staphylococcus and gram + RED WORDS Flashcards
most virulent member of Staphylococcus genus?
S. aureus
Toxin mediated diseases
food poisoning, scalded skin syndrome, toxic shock syndrome
cutaneous diseases
carbuncles, folliculitis, furuncles, impetigo, wound and surgery infections
alpha toxin
- aggregates into heptamer forming pore
- Encoded on both chromosome and plasmid
- Disrupts smooth muscles of blood vessels
- Binds to cell surface, aggregates to form port for efflux of ions
beta toxin or sphingomyelinase C
catalyzes phospholipids at sphingomyelin
delta toxin
membrane surfactant with detergent like effect
gamma and Panton-Valentine [P-V] leucocidin
- bicomponenttoxins that form pores
* S-slow component set and F-fast component set- capable of producing six distinct toxins
two exfoliative toxins (A and B)
- responsible for Staphylococcal scalded skin syndrome (SSSS-ie. exfoliative dermatitis)
- ET-A is heat stable and the gene is phage associated
- ET-B is heat labile serine protease that splits desmoglein-1, part of cell adhesion structures (desmosomes) of intercellular bridges
Five cytolytic or membrane-damaging toxins
1) alpha toxin
2) beta toxin or sphingomyelinase C
3) delta toxin
4) gamma and Panton-Valentine [P-V] leucocidin
5) two exfoliative toxins (A and B)
desmoglein-1
part of ET-B exfoliating toxins
*part of cell adhesion structures (desmosomes) of intercellular bridges
Scalded skin syndrome
Toxin-Mediated Disease
*looks like large peeling blisters (in infants)
Bullous impetigo
Toxin-Mediated Disease
- localized form of SSSS
- superficial skin blisters
- specific strains of toxin-producing S. aureus phage
hemoptysis
coughing up blood
*caused by Pneumonia; MRSA is responsible fro sever form of necrotizing pneumonia with hemoptysis, septic shock and high mortality
empyema
pus filled areaof infection occurs in some pneumonia patients
