M6 Flashcards
S.aureus and S.epidermis
S. aureus - Gram +
S.epidermis - Gram +
features of S.aureus
- 20-60% colonisation
- anterior nares and perineum
- nasocomial and community
- coagulase +
features of S.epidermis
- 100% colonisation
- skin + mucus membrane
- gram +
- coagulase -
what is the direct transmission of Staphylococci?
hand, skin, mucous
what is the indirect transmission of staphylococci?
instruments, bedding and door handles
can enter (opportunistic) by
Hair follicles and glands - boils
- broken skin - cuts, bites and injections
list three examples of types of virulence factors
- Fibrinogen binding protein
- leukocidin (PVL)
- TSST-1 (toxin)
what is the function of fibrinogen binding protein?
adhesin
what is the function of leukocidin (PVL)
kills leukocytes
what is the function of TSST-1 (toxin)?
Shock, rash, desquamation
what is the effect of TSST-1?
rapid progression (48 hours) high fever, vomiting, diarrhea, sore throat, muscle pain
what is a superantigen?
- ability to promote massive activation of immune cells leading to release of inflammatory mediators that can lead to hypotension, shock, organ failure, death
1 in 5 T cells
what adhesins allow bacteria to bind?
- fibrinogen binding
- collagen binding
how does protein A evade host defences?
for coagulase +ve only
binds Fc portion of IgG antibodies
what does PVL stand for?
Panton-Valentine Leukocidin
