Gram +ve staphylococci Flashcards
which are more resistant gram +ve or -ve? why?
gram +ve as have thicker cell wall
what are the 2 most common types of staphylococci
S.aureus
S.epidermis
where is S.aureus found?
nose
perineum
oral environment
who is S.aureus seen as a risk to?
everyone
is S.aureus coagulase +ve or -ve? what does this mean?
coagulase +ve
good at coagulating plasma
how does S.aureus present in the body?
superficial lesions, systemic, toxinoses
what are virulence factors?
Proteins which can be assigned to increasing its ability to cause damage to the host
name virulence factors of S.aureus
fibrinogen binding protein - adhesins
coagulase
leukocidin PVL
TSST-1
what do adhesins do?
allow it to bind to fibrinogen, collagen etc. so it can coagulate plasma
allowing it to colonise wound sites and produces proteins that damage the host
what does leukocidin PVL do?
Causes damage to white blood cells (leukocytes)
how do PVL and a-toxins present in the body?
linked with CA-MRSA responsible for necrotising pneumonia and contagious severe skin infections
how does TSST-1 present in the body?
shock, rash, desquamation
what is desquamation?
outermost layer of tissue e.g. skin is shed
TSST-1 is a superantigen what does this mean?
overstimulate the immune system, aids more aggressive bacteria that thrive in a more hostile environment
S.aureus primarily causes what?
skin infections
