Staph

Question 1

The first test to run on cocci grown aerobically?

What test should follow?

Answer 1

Gram’s stain.

Catalase.

Question 2

What is catalase?

What does a positive catalase test look like?

Answer 2

An enzyme (produced by aerobes) used to neutralize oxidative toxins (such as H2O2).

Bubbles

Question 3

You have a G+ aerobic, catalase + cocci - what test is next?

Answer 3

coagulase

Question 4

What methods can be used to test the presence of coagulase?

Answer 4

Slide (agglutination) or tube (clot).

Question 5

Who am I? G+ aerobic clusters, catalase +, coagulase+

Answer 5

S. aureus

Question 6

You have a G+ aerobic cocci, catalase (+), coagulase (-) - what test is next?

Answer 6

Bacitracin sensitivity

Question 7

Who am I? Aerobic G+ cocci, catalase (+), coagulase (-), bacitracin (+/sensitive).

Answer 7

Micrococcus sp.

Question 8

What is the PYR test (L-Pyrrolidonyl-β-naphthylamide)?

Answer 8

Test used to detect an enzyme that breaks down specific protein structures.

Question 9

Who am I? Aerobic G+ cocci, catalase (+), coagulase (-), bacitracin (-/resistant), PYR (+)?

Answer 9

Staph. lugdenesis

Question 10

Aerobic G+ cocci, catalase (+), coagulase (-), bacitracin (-/resistant), PYR (-) - what’s the next test?

Answer 10

novobiocin resistance

Question 11

Aerobic G+ cocci, catalase (+), coagulase (-), bacitracin (-/resistant), PYR (-), novibiocin (+/sensitive)?

Aerobic G+ cocci, catalase (+), coagulase (-), bacitracin (-/resistant), PYR (-), novibiocin (-/resistant)?

Answer 11

Staph. epi

Staph. saprophyticus

Question 12

What test distinguishes staph from strep?

Answer 12

catalase