Sketchy Micro: Staph Epidermidis

Question 1

Staphylococcus epidermidis and saprophyticus are Gram-_____________.

Answer 1

positive (just like the violet drapes)

Question 2

S. epidermidis often infects _______________.

Answer 2

prosthetic joints, artificial heart valves, and catheter tubing (just like the hardware, heart-shaped valves, and catheter-like tubes beneath the sink that the plumber is working on)

Question 3

How is S. epidermidis able to be so infective?

Answer 3

It secretes a polysaccharide biofilm that allows it to adhere to surfaces and hide from antibiotics. (Think of the biofilm covering the hardware beneath the sink.)

Question 4

What is the recommended drug for treating S. epidermidis?

Answer 4

Vancomycin (like the plumber’s van outside the window)

Question 5

Many healthy people will grow S. epidermidis if you culture their blood. Why?

Answer 5

Because S. epidermidis is everywhere!

Question 6

What is a common way of distinguishing between S. epidermidis and S. saprophyticus?

Answer 6

S. epidermidis is novobiocin-sensitive (just like the plumber’s sensitive navel exposed beneath the sink)

S. saprophyticus, however, is novobiocin-resistant (just like the girl’s covered navel)

Question 7

S. epidermidis and S. saprophyticus are both (like all Staphylococci) catalase-_____________.

Answer 7

positive

Think of the cat watching the plumber work.

Question 8

S. saprophyticus is most commonly found in _____________.

Answer 8

UTIs in sexually active females (think of the girl on the counter, looking flirtatiously at the plumber and twirling her hair: she’s holding a drink that looks like a bladder)

Question 9

S. epidermidis and S. saprophyticus are both urease-_______________.

Answer 9

positive (think of the ammonia bottle on the counter)

Question 10

This is important: S. epidermidis and S. saprophyticus are both coagulase-_____________.

Answer 10

negative (like the untouched – un-coagulated –jello on the counter)