B1.1 CATALASE-POSITIVE GRAM-POSITIVE COCCI

Question 1

Clinically significant catalase-positive gram-positive cocci

Answer 1

Staphylococcus aureus

Question 2

COAGULASE-NEGATIVE STAPHYLOCOCCI
spp

Answer 2

Staphylococcus epidermidis
Staphylococcus haemolyticus
Staphylococcus saprophyticus
Staphylococcus lugdunensis
Staphylococcus schleiferi

Staphylococcus capitis
Staphylococcus caprae
Staphylococcus warneri
Staphylococcus hominis
Staphylococcus auricularis
Staphylococcus cohnii
Staphylococcus xylosus
Staphylococcus simulans

Question 3

COAGULASE-NEGATIVE STAPHYLOCOCCI
that has clumping factor which may show false coagulase postive result

Answer 3

schleiferi at lugdunensis

Question 4

Micrococcus spp. and related
genera

Answer 4

Alloiococcus

Question 5

What family do Staphylococcus species belong to?

Answer 5

Staphylococcaceae

Question 6

Are Staphylococcus species catalase-positive or catalase-negative?

Answer 6

Catalase-positive

Question 7

What is the oxygen requirement for most Staphylococcus species?

Answer 7

They are aerobic or facultative anaerobic

Question 8

Which Staphylococcus subspecies are obligate anaerobes?

Answer 8

Staphylococcus aureus subsp. anaerobius and S. saccharolyticus

Question 9

Are Staphylococcus species motile or nonmotile?

Answer 9

Nonmotile

Question 10

Are Staphylococcus species spore-forming?

Answer 10

No, they are non-spore-forming

Question 11

What is the shape and size of Staphylococcus cells?

Answer 11

Spherical cells (0.5 to 1.5 μm) that appear singly, in pairs, or in clusters

Question 12

Where are Staphylococcus species commonly found in the human body?

Answer 12

On the skin, mucous membranes, and in the intestines

Question 13

Describe the appearance of Staphylococcus colonies on a blood agar plate (BAP).

Answer 13

Colonies are medium-sized (4 to 8 mm), cream-colored, white, or rarely light gold, and have a “buttery” look

Question 14

What is a distinguishing feature of Staphylococcus aureus colonies on BAP?

Answer 14

They may be β-hemolytic

Question 15

What is the appearance of colonies for other Staphylococcus species on BAP?

Answer 15

Some may have gray colonies.

Question 16

Differential Test Between Staphylococci and Micrococci

Bacitracin (0.04 U)

Answer 16

Staphylococci - R
Micrococci - S (> 10mm)

Question 17

Differential Test Between Staphylococci and Micrococci

Furazolidone Suceptibility
Test (100ug)

Answer 17

Staphylococci - S (>15mm)
Micrococci - R (6-9 mm)

Question 18

Differential Test Between Staphylococci and Micrococci

Lysostaphin Sensitivity Test

Answer 18

Staphylococci - S (10-16 mm)
Micrococci - R

Question 19

Differential Test Between Staphylococci and Micrococci

Modified Oxidase Test/Microdase Test

Answer 19

Staphylococci - Negative
Micrococci - Positive

Question 20

Differential Test Between Staphylococci and Micrococci

Growth on Furoxone-Tween 80-oil Red O Agar

Answer 20

Staphylococci - Negative
Micrococci - Positive

Question 21

Differential Test Between Staphylococci and Micrococci

Aid production from Glycerol (with erythromycin)

Answer 21

Staphylococci - Positive
Micrococci - Negative

Question 22

Differential Test Between Staphylococci and Micrococci

OF reaction

Answer 22

Staphylococci - Fermenter
Micrococci - Oxidizer