G+ STREPTOCOCCI

Question 1

general characteristics of Strep spp.

Answer 1

gram + cocci in pairs/chains
catalase -
pinpoint colonies
facultative anaerobes

Question 2

what is unique about the cell wall of Strep spp.

Answer 2

antigen C-carbohydrate

Question 3

classification:

based on physiologic/temp reqs

Answer 3

academic/bergey’s

Question 4

academic/bergey’s:
grows only at 37 C
beta-hemolytic

Answer 4

pyogenic group

Strep pyogenes

Question 5

academic/bergey’s:
grows at 37 C and 45 C
alpha/gamma hemolytic

Answer 5

viridans group

Enterococcus faecalis

Question 6

academic/bergey’s:
grows at 10 C and 37 C
gamma hemolytic

Answer 6

lactococci group

Question 7

academic/bergey’s:

grows at all temp

Answer 7

enterococci group

Question 8

classification:
based on C-carbohydrate
most significant

Answer 8

lancefield

Question 9

classification:

based on hemolytic pattern

Answer 9

smith and brown’s

Question 10

complete hemolysis

Answer 10

beta hemolysis

clear zone

Question 11

partial hemolysis

Answer 11

alpha hemolysis

green discoloration

Question 12

non hemolytic

Answer 12

gamma hemolysis

Question 13

beta hemolytic streps:

Answer 13

S. pyogenes

S. agalactiae

Question 14

alpha hemolytic streps:

Answer 14

S. pneumoniae

Viridans group

Question 15

group A streps

Answer 15

S. pyogenes

Question 16

group B streps

Answer 16

S. agalactiae

Question 17

group D streps

Answer 17

E. faecalis

S. bovis

Question 18

Viridans group:

Answer 18

S. mutans
S. mitis
S. salivarius

Question 19

virulence factor of S. pyogenes

Answer 19

M protein

Question 20

S. pyogenes:
hemolysin that is responsible for lysing the rbcs;
oxygen labile;
higly immunogenic;

Answer 20

streptolysin O

Question 21

S. pyogenes:
oxygen stable;
non-immunogenic

Answer 21

streptolysin S

Question 22

S. pyogenes:

lysis of fibrin clots

Answer 22

streptokinase

Question 23

S. pyogenes:

spreading factor

Answer 23

hyaluronidase

Question 24

strep superantigens

Answer 24

pyrogenic/erythrogenic toxins
SpeA
SpeB
SpeC
SpeF

Question 25

most common manifestation of S. pyogenes

Answer 25

strep throat

Question 26

necrotizing fasciitis associated with S. pyogenes

Answer 26

type 2 NF

Question 27

post-strep sequela:
1 month after infection
fever, inflammation of the heart, joints, and blood vessels

Answer 27

rheumatoid fever

Question 28

post-strep sequela:
more common in children
deposition of antigen-antibody complexes in the glomeruli

Answer 28

glomerulonephritis

Question 29

only strep that expresses group B antigen

Answer 29

S. agalactiae

Question 30

virulence determinant of S. agalactiae

Answer 30

capsular sialic acid

Question 31

disease associated with S. agalactiae

Answer 31

neonatal GBS disease

Question 32

non-groupable strep

Answer 32

S. pneumoniae

Question 33

most important virulence factor of S. pneumoniae

Answer 33

capsule

Question 34

clinical manifestations of S. pneumoniae

Answer 34

bacterial and lobar pneumoniae
meningitis
bacteremia

Question 35

strep vaccine:

Answer 35

heptavalent pneumococcal conjugate vaccine

Question 36

drug of choice for treating group A, B, S. pneumoniae infections

Answer 36

penicillin

Question 37

strep associated with bacterial endocarditis

Answer 37

S. mitis

Question 38

strep associated with dental caries

Answer 38

S. mutans

Question 39

bacitracin (B) and sulfamethoxazole/trimethoprim (SXT) disk is performed on:

Answer 39

beta hemolytic strep

group A - S. pyogenes

Question 40

optochin (P) is performed on:

Answer 40

alpha hemolytic strep

S. pneumoniae

Question 41

sensitive on bacitracin:

Answer 41

S. pyogenes

Question 42

sensitive on optochin:

Answer 42

S. pneumoniae

Question 43

tests for determining group D/Enterococcus

Answer 43

6.5% NaCl + (turbidity)

Bile esculin + (blackening)