Gram Positive Bacteria

Question 1

Staphylococcus aureus - transmission

Answer 1

• transmission direct or indirect contact
• bacteria survives in air, dust and on objects for days
• lives on skin & moist areas
• endogenous or exogenous infection (immunocompromised)

Question 2

Staphylococcus aureus - virulence factors

Answer 2

• catalase positive (like all staph)
• coagulase & DNAse
• hyaluronidase, lipase, toxin A
• enterotoxin, TSS toxin 1
• fibrinolysin & haemolysin

Question 3

Staphylococcus aureus - clinical

Answer 3

• immunocompetent or immunocompromised
• readily colonize medical implants (intravascular catheters)
• pneumonia, TSS, endocarditis, osteomyelitis, skin & soft tissue infections

Question 4

Staphylococcus aureus - lab

Answer 4

culture

• creamy white, round colonies (all staph)
• hemolytic zones around colony, may exhibit yellow pigment

Question 5

Staphylococcus aureus - treatment

Answer 5

Cloxacillin (otherwise vancomycin)

Question 6

Staphylococcus aureus - general

Answer 6

-non-motile, non-sporing facultative anaerobes