Staphyloccocus Aureus

Question 1

Story? Staph Aureus

Answer 1

Old lady with hip replacement
Drug user - dirty needle (endocarditis)
Young adult wth a sty

Question 2

Have does staph aureus tend to enter the body?

Answer 2

Break in the skin - surgical wound infection, central venous catheter, ingrown hair

Question 3

Virulence factors? Staph Aureus

Answer 3

Protein A - anti-opsonin effect
Slime production
Phagocytosis resistant capsule
FnBP - binding factor - contains integrity so sticks to cells
Exotoxins - stimulates T cells and cause toxic shock

Question 4

Transmission? Staph Aureus

Answer 4

Ingestion
Inoculation
Contagious e.g. Tampon

Question 5

Bacteria? Staph Aureus

Answer 5

Gram pos cocci

Question 6

Investigations? Staph Aureus

Answer 6

Blood agar - yellow haemolytic - aureus = golden

Coagulase test - Staph Aureus clot in plasma - should be positive

Question 7

What is the difference between community acquired and hospital acquired MRSA?

Answer 7

Hospital = generally old, ill, disabled patients. Resistance common - low antibiotic affinity for beta lactam antibiotics
Community = often young, healthy patients - skin infections, pneumonia, septic shock - more sensitive to antibiotics

Question 8

Treatment? Staph Aureus

Answer 8

Drainage of abscesses

Often resistance to penicillin - Vancomycin (last resort)