Staphylococcus Aureus Flashcards
Where is staphylococcus aureus normally found on the body?
It is a normal commensal of the skin and mucous membranes.
How does staphylococcus aureus normally cause infection?
When there is a break in the skin - IV lines, catheters, wounds, surgery, etc.
Immunocompromised patients.
How does staphylococcus aureus spread?
For people that are carriers, they may infect non-carriers through direct contact, or through indirect contact - this could be through food, or touching surfaces which can then be picked up onto the hands of non-carriers.
What are the virulence factors of staphylococcus aureus?
Enterotoxins.
Cytolytic exotoxins.
Exfoliatin toxin.
Toxin shock syndrome toxin 1.
Protein A.
What is the common clinical presentation of a staphylococcus aureus infection, and what can the complications be?
Skin abscesses, often at the site of the break in skin.
There can be swelling, accumulation of pus, and necrosis of the tissue - often causes cellulitis.
Bacteraemia can result in septicaemia, where the bacteria can infect the lung, kidney, heart or meninges. It can be rapidly fatal.
What is the gram stain and description for staphylococcus aureus?
Gram positive cocci, in clusters. It is coagulase-positive and an anaerobic bacteria.
What is the treatment for staphylococcus aureus infections?
Flucloxacillin if not MRSA.
Vancomycin if MRSA.
What is the function of fluclocaxillin and vancomycin?
They are both cell wall inhibitors.
How is staphylococcus aureus tested for?
Nasal swab to culture it.
Coagulase test - the only positive staphylococcus.
