VIRULENCE FACTOR (STAPHYLOCOCCI)

Question 1

A heme enzyme that catalyzes the decomposition of H2O2 to water and oxygen:

Answer 1

catalase

Question 2

Differentiates (+) Staphylococci & (+) Micrococci from Streptococci (-):

Answer 2

catalase

Question 3

Reagent of catalase test:

Answer 3

hydrogen peroxide

Question 4

(+) result of catalase test:

Answer 4

bubble formation/ effervescence

Question 5

Aerobic catalase test:

Answer 5

3% H2O2

Question 6

Anaerobic catalase test:

Answer 6

15% H2O2

Question 7

Superoxidase test:

Answer 7

30% H2O2

Question 8

Causes pseudo-catalase reaction:

Answer 8

bubbles = need oxygen = AER

Aerococcus
Enterococcus
Rothia

Question 9

Coagulates the fibrinogen in plasma:

Answer 9

coagulase

Question 10

Promotes the formation of a fibrin layer therefore protecting the bacteria from phagocytosis:

Answer 10

coagulase

Question 11

Major virulence factor of S. aureus:

Answer 11

coagulase

Question 12

Coagulase bound to the cell wall:

Answer 12

cell-bound coagulase/clumping factor

Question 13

Cell-bound coagulase:

Answer 13

it causes bacterial cell to agglutinate in plasma

Question 14

Coagulase free from the cell wall:

Answer 14

unbound coagulase/free factor

Question 15

Unbound coagulase:

Answer 15

it causes clot formation when bacterial cells are incubated with plasma

Question 16

It enhances invasion and survival in tissues; breaks down hyaluronic acid resulting to spread of bacteria:

Answer 16

hyaluronidase

Question 17

Other names of hyaluronidase:

Answer 17

spreading-factor enzyme, Duran-Reynold factor

Question 18

It dissolves fibrin clot:

Answer 18

staphylokinase

Question 19

Other names of staphylokinase:

Answer 19

fibrinolysin

Question 20

Essential for the survival in sebaceous areas of the body:

Answer 20

lipase

Question 21

It is important for the formation of furuncles, carbuncles and boils:

Answer 21

lipase

Question 22

Other names of lipase:

Answer 22

fat-splitting enzyme

Question 23

Increases organisms mobility:

Answer 23

deoxyribonuclease (DNAse) and phosphatase

Question 24

Breaks down penicillin and other beta-lactam drugs:

Answer 24

beta-lactamase

Question 25

Acts as neurotoxins that stimulate the vagus nerve to cause vomiting:

Answer 25

enterotoxin

Question 26

Resistant to hydrolysis by the gastric and intestinal enzymes:

Answer 26

enterotoxin

Question 27

True or False: Reheating contaminated food will not prevent the disease.

Answer 27

TRUE. It is stable to heating at 100C for 30 minutes. They also do not cause any detectable odor or change in appearance or taste to food.

Question 28

Most common enterotoxin:

Answer 28

enterotoxin A (78%)

Question 29

Responsible for food poisoning (the infected food handler is the source of contamination):

Answer 29

enterotoxin A, B, and D

Question 30

Associated with pseudomembranous enterocolitis:

Answer 30

enterotoxin B

Question 31

Causes enterocolitis:

Answer 31

enterotoxin B, C, G, and I

Question 32

Is a pore-forming exotoxin that kills WBC; it suppresses phagocytosis:

Answer 32

leukocidin/panton-valentine leukocidin

Question 33

Responsible for necrotizing skin and soft tissue infections:

Answer 33

PVL

Question 34

PVL causes:

Answer 34

community-acquired MRSA

Question 35

It causes anemia- making iron available for microbial growth:

Answer 35

hemolysin

Question 36

Disrupts smooth muscle in blood vessels; toxic to RBCs, WBCs, hepatocytes, platelets:

Answer 36

alpha hemolysin

Question 37

Alpha hemolysin is exhibited by:

Answer 37

S. aureus

Question 38

Catalyzes the hydrolysis of membrane phospholipids resulting in cell lysis:

Answer 38

beta hemolysin

Question 39

It destroys sphingomyelin:

Answer 39

beta hemolysin

Question 40

Other names of beta hemolysin:

Answer 40

hot-cold lysin, sphingomyelinase C

Question 41

Cytolytic to RBCs and demonstrates nonspecific membrane toxicity to other mammalian cells:

Answer 41

delta hemolysin

Question 42

Delta hemolysin is exhibited by:

Answer 42

S. aureus, S. epidermidis, S. hemolyticus

Question 43

Responsible for the various skin, wound, and deep tissue infections:

Answer 43

gamma hemolysin

Question 44

Gamma hemolysin is exhibited by:

Answer 44

S. aureus

Question 45

Associated with PVL:

Answer 45

gamma hemolysin

Question 46

It causes the epidermal layer of the skin to slough off:

Answer 46

exfoliating toxin A and B

Question 47

It causes SSS or Ritter disease:

Answer 47

exfoliating toxin A and B

Question 48

Other names of Exfoliating toxin:

Answer 48

epidermolytic toxin

Question 49

A chromosomal-mediated toxin:

Answer 49

TSST-1

Question 50

Causes menstruating-associated TSS:

Answer 50

TSST-1

Question 51

Other names of TSST-1:

Answer 51

enterotoxin F, pyogenic exototxin C

Question 52

Immunologically active substance found in the cell wall:

Answer 52

protein A

Question 53

Antiphagocytic by competing with neutrophils for the fc portion of specific opsonin:

Answer 53

protein A

Question 54

Appear as a slime layer/biofilm; inhibits phagocytosis:

Answer 54

capsule

Question 55

Activates complement, IL-1, and act as a chemotactic factor for the recruitment of PMNs:

Answer 55

peptidoglycan