Lecture | Streptococcus & Enterococcus

Question 1

catalase negative gram-positive cocci in pairs or chains

Answer 1

streptococci

Question 2

morphology: Streptococcus forms in

Answer 2

chain

Question 3

morphology: Staphylococcus forms in

Answer 3

clusters

Question 4

Used to differentiate Streptococcus from Micrococcaeceae

Answer 4

Catalase test

Question 5

Streptococcus is catalase ?

Answer 5

catalase negative

Question 6

Staphylococcus or other Micrococcus is catalase ?

Answer 6

catalase positive

Question 7

normal flora of Upper respiratory tract and skin lesions

Answer 7

S,pyogenes

Question 8

normal flora of Upper respiratory microbiota

Answer 8

S.penumoniae

Question 9

Lancefield groups based on carbohydrates in the cell wall

Answer 9

BETA-HEMOLYTIC STREPTOCOCCI

Question 10

Group A

Answer 10

S.pyogenes

Question 11

Group B

Answer 11

S.agalactiae

Question 12

Group C

Answer 12

S.dysgalactiae

Question 13

Group D

Answer 13

Enterococcus spp. and Streptococcus bovis complex

Question 14

most clinically important Lancefield group A

Answer 14

Streptococcus pyogenes

Question 15

Virulence factors of S. pyogenes responsible for the betahemolytic pattern on blood agar plates

Answer 15

Streptolysin O and S

Question 16

one of the most aggressive pathogens encountered in clinical microbiology laboratories.

Answer 16

S. pyogenes

Question 17

flesh eating bacteria

Answer 17

S. pyogenes

Question 18

oxygen-stable, nonimmunogenic, hemolysin capable of lysing erythrocytes, leukocytes, and platelets in the presence of room air. (20-22C)

Answer 18

Streptolysin S

Question 19

it means cannot trigger immune response

Answer 19

nonimmunogenic

Question 20

mmunogenic, capable of lysing the same cells and cultured cells, is broken down by oxygen

Answer 20

Streptolysin O

Question 21

will produce hemolysis only in the absence of room air.

Answer 21

Streptolysin O

Question 22

Streptolysin O is inhibited by this resulting in the absence of the development of protective antibodies associated with skin infection.

Answer 22

cholesterol in skin lipids

Question 23

virulent factor of S. pyogenes that permits the bacterial adherence to the respiratory epithelium

Answer 23

Lipotechoic acid

Question 24

virulent factor of S. pyogenes released and produce scarlet fever

Answer 24

Streptococcal Pyrogenic Exotoxins (SPEs)

Question 25

occurs in association with streptococcal pharyngitis and is manifested by a rash of the face and upper trunk.

Answer 25

scarlet fever

Question 26

The SPEs are erythrogenic toxins produced by

Answer 26

lysogenic strains

Question 27

They are heat labile and rarely found in group C and G streptococci.

Answer 27

Streptococcal Pyrogenic Exotoxins (SPEs)

Question 28

SPEs act as superantigens activating macrophages and T-helper cells and inducing the release of powerful immune mediators such as

Answer 28

(IL)-1, IL-2, IL-6, tumor necrosis factor (TNF)-alpha, TNF-beta, interferons, and cytokines

Question 29

from streptococcal infection through the mouth

Answer 29

Streptococcal toxic shock syndrome

Question 30

Streptococcal toxic shock syndrome, typified by multisystem involvement including

Answer 30

renal and respiratory failure, rash, and diarrhea, is a serious disease mediated by production of potent SPE.

Question 31

most important virulence factor of our Streptococcus pyogenes

Answer 31

M protein - anti-phagocytic cell wall

Question 32

anti-phagocytic and also very immunogenic

Answer 32

M protein

Question 33

associated with rheumatic fever

Answer 33

Class 1M protein

Question 34

Associated with glomerulonephritis

Answer 34

class I or II