1 Staphylococci

Question 1

Gram-positive cocci arranged in grape-like clusters

A- staphylococci
B- streptococci
C- enterococci

Answer 1

Staphylococci

Question 2

Coagulase positive staphylococci

A- S. epidermidis
B- S. aureus
C- S. saprophyticus

Answer 2

S. Aureus

Question 3

Coagulase negative staphylococci

Answer 3

S. epidermidis & S. saprophyticus

Question 4

The most important human pathogen :

A- S. aureus
B- S. epidiermidis
C- S. saprophyticus

Answer 4

S. aureus

Question 5

Most strains of S. aureus produce :

Answer 5

Golden yellow endopigment

Question 6

The protein in cell wall of s. aureus and an important virulence factor is

Answer 6

Protein A

Question 7

Why protein A is an important virulence factor for S. aureus

Answer 7

Because s.aureus is antiphagocytic

Question 8

What type of staphylococci act as superantigens ?
A- aureus
B- epidermidis
C- saprophyticus

Answer 8

Aureus

Question 9

……. Differentiates staphylococci (catalase positive) from streptococci (catalase negative)
A- catalase test
B- coagulase

Answer 9

Catalase test

Question 10

Converts fibrinogen to fibrin which deposits on the surface of the organism protecting it from phagocytosis. So, it is considered as important virulence factor.

Answer 10

Coagulase

Question 11

Due to this enzyme, most suppurative staphylococcal lesions are localized
A- catalase
B- coagulate

Answer 11

Coagulate

Question 12

important in hospital acquired infections (MRSA).

Answer 12

S. Aureus

Question 13

The best method for typing staphylococci foe epidemiological purposes

Answer 13

Bacteriophage typing

Question 14

Second to E. coli as a cause of community acquired urinary tract infection in sexually active young women.

Answer 14

S. Saprophyticus

Question 15

Considered as one of the normal flora of the skin & mucous membranes

Answer 15

S. Epidermidis

Question 16

90% of staphylococci though production of

Answer 16

Penicillinases, beta lactamases

Question 17

20% of staphylococci are resistant called …….. by modified penicillin binding proteins (PBP)

Answer 17

Methicillin resistant staph aureus (MRSA)

Question 18

Current drug of choice for treat MRSA

Answer 18

Vancomycin

Question 19

organisms may spread via lymphatics
or blood (……….) to other parts of the body causing …………. .

Answer 19

bacteraemia, deep seated lesions.

Question 20

This syndrome was first described in menstruating females using
tampons contaminated with S. aureus. It may also occur with wound or localized infections.

Answer 20

Toxic shock syndrome (TSS)

Question 21

TSS is due to

Answer 21

Toxic shock syndrome toxin (TSST-1)

Question 22

Scalded skin syndrome due to

Answer 22

Exfoliative toxin

Question 23

Causes infection of the prosthetic devices

Answer 23

S. epidermidis

Question 24

Treatment of deep/metastatic infection

Answer 24

semi-synthetic penicllins, cephalosporins, erythromycin, clindamycin.

Question 25

Treatment of endocarditis

Answer 25

semi-synthetic penicillin + an aminoglycoside